Online Links:
| Value | Definition |
|---|---|
| H2O | water |
| Jdb | Diabase breccia of Mount Umunhum |
| Jog | Gabbro cumulates |
| Joi | Intrusive complex |
| Jos | Serpentinized ultramafic rocks |
| Jos? | Serpentinized ultramafic rocks, identification uncertain |
| Jou | Ultramafic cumulates |
| Jou? | Ultramafic cumulates, identification uncertain |
| Jov | Basalt, andesite, and dacite |
| Jov? | Basalt, andesite, and dacite, identification uncertain |
| Jt | Altered tuff of Mount Umunhum |
| KJm | Mudstone (Lower Cretaceous and Upper Jurassic) |
| KJm? | Mudstone (Lower Cretaceous and Upper Jurassic), identification uncertain |
| Kuc | Conglomerate (Upper Cretaceous) |
| Kus | Sandstone and shale |
| Kus? | Sandstone and shale, identification uncertain |
| MD | Mine dump |
| PP | Percolation pond |
| QTsc | Santa Clara Formation |
| QTsc? | Santa Clara Formation, identification uncertain |
| Qal | Alluvium, undivided |
| Qhc | Stream Channel deposits |
| Qhc? | Stream Channel deposits, identification uncertain |
| Qhf | Alluvial fan deposits (Holocene) |
| Qls | Landslide deposits, undivided |
| Qls? | Landslide deposits, undivided, identification uncertain |
| Qoa | Older alluvium, undivided |
| Qpf | Alluvial fan deposits (Pleistocene) |
| Qt | Alluvial terrace deposits, undivided |
| Tbm | Mudstone (late Eocene) |
| Tbu | Undivided sandstone and shale |
| Tcm | Mottled mudstone and sandstone of Mount Chual |
| Tcm? | Mottled mudstone and sandstone of Mount Chual, identification uncertain |
| Tcml | Limestone |
| Tls | Sandstone and mudstone |
| Tls? | Sandstone and mudstone, identification uncertain |
| Tms | Monterey Shale |
| Tp | Purisima Formation |
| Tsr | Rices Mudstone Member |
| Tsr? | Rices Mudstone Member, identification uncertain |
| Tst | Twobar Shale Member |
| Tt | Temblor Sandstone |
| Ttv | Volcanic and intrusive rocks |
| Tus | Unnamed sandstone |
| Tv | Vaqueros Formation |
| Tv? | Vaqueros Formation, identification uncertain |
| Tvb? | Basalt flows, identification uncertain |
| af | Artificial fill |
| am | Amphibolite blocks |
| bs | Blueschist blocks |
| ch | Chert blocks |
| dbm | Diabase and gabbro of Morrell Cutoff Road and Laurel Creek |
| fm | Melange of the Central belt |
| fm? | Melange of the Central belt, identification uncertain |
| fmc | Radiolarian chert |
| fmc? | Radiolarian chert, identification uncertain |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fms? | Sandstone (Upper and (or) Lower Cretaceous), identification uncertain |
| fmv | Basaltic volcanic rocks |
| fmv? | Basaltic volcanic rocks, identification uncertain |
| fpl | Foraminiferal limestone |
| fpv | Volcanic rocks |
| fpv? | Volcanic rocks, identification uncertain |
| sc | Silica-carbonate rock |
| v | Basaltic volcanic rock blocks |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| atten. fault, certain | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| atten. fault, concealed | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| atten. fault, concealed, queried | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| atten. fault, inferred | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, inferred | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| crack, 10/17/89 | Surface crack recognized as deformation that occurred during Loma Prieta earthquake of October 17, 1989. |
| dam | The edge of a dam. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| glauconitic marker | Mappable sedimentary horizon composed largely of glauconite pellets (³ 30%); consistently occurs at same stratigraphic level. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| thrust fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| thrust fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| topographic escarpment | Approximately linear steep topographic gradient separating less steep topography. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| approx. attitude | Dip and strike of planar feature approximated at a distance in the field or inferred from air photos. |
| axial trend, small anticline | Line delineates trend direction of small anticline. |
| axial trend, small syncline | Line delineates trend direction of small syncline. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. |
| bedding, in trench | Symbol denotes dip and strike measured from exposures at geotechnical or construction trench site. |
| complex folds | Symbol denotes axial trend and plunge direction(s) of outcrop-scale folds. |
| flat bedding | Sedimentary layers that retain their original horizontal position were observed at this point. |
| fold axis dip | Arrow and number define direction and degree of inclination of axial plane of fold. |
| foliation | Metamorphic foliation was observed at this point. |
| inclined lineation | Arrow and number denotes direction and amount of rake of linear feature on surface of a plane. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| lava flow attitude, w/tops | Ball on symbol denotes that top of flow unit is known from texture or pillow surface. |
| ot bedding | Originally horizontal sedimentary layers were observed at this point. Evidence that the beds are overturned was observed, although that observation may not have been made at this point. |
| ot bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were overturned. |
| vert bedding | Originally horizontal sedimentary layers were observed at this point. These layers are now vertical. |
| vert bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. These layers are now vertical. |
| vert foliation | Symbol denotes that foliation in rock is vertical. |
| vert lava flow or dike or sill | Symbol denotes that volcanic flow or dike or sill is vertical. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., anticline, inferred, queried | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, concealed | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, inferred, queried | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| Value | Definition |
|---|---|
| H2O | water |
| Jos | Serpentinized ultramafic rocks |
| PP | Percolation pond |
| Qal | Alluvium, undivided |
| Qhb | Basin deposits |
| Qhc | Stream Channel deposits |
| Qhf | Alluvial fan deposits (Holocene) |
| Qhfp | Floodplain deposits |
| Qhl | Levee deposits |
| Qpf | Alluvial fan deposits (Pleistocene) |
| Tms | Monterey Shale |
| Tt | Temblor Sandstone |
| Tt? | Temblor Sandstone, identification uncertain |
| Tus? | Unnamed sandstone, identification uncertain |
| af | Artificial fill |
| fm | Melange of the Central belt |
| fmc | Radiolarian chert |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fms? | Sandstone (Upper and (or) Lower Cretaceous), identification uncertain |
| fpv | Volcanic rocks |
| Value | Definition |
|---|---|
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| ot bedding | Originally horizontal sedimentary layers were observed at this point. Evidence that the beds are overturned was observed, although that observation may not have been made at this point. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, concealed | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| Value | Definition |
|---|---|
| H2O | water |
| Jog | Gabbro cumulates |
| Joi | Intrusive complex |
| Jos | Serpentinized ultramafic rocks |
| Kgr | Granitic and metamorphic rocks |
| Kuc | Conglomerate (Upper Cretaceous) |
| Kus | Sandstone and shale |
| Qa | Aromas Sand |
| Qal | Alluvium, undivided |
| Qls | Landslide deposits, undivided |
| Qls? | Landslide deposits, undivided, identification uncertain |
| Qmt | Alluvium, undivided |
| Qof | Older floodplain deposits |
| Qof? | Older floodplain deposits, Identification uncertain |
| Qt | Alluvial terrace deposits, undivided |
| Tbc | Conglomerate (middle Eocene or younger) |
| Tbm | Mudstone (late Eocene) |
| Tbs | Sandstone (middle Eocene or younger) |
| Tbu | Undivided sandstone and shale |
| Tcm | Mottled mudstone and sandstone of Mount Chual |
| Tcms | Undivided sandstone and shale |
| Tla | Lambert Shale |
| Tlo | Lompico Sandstone |
| Tls | Sandstone and mudstone |
| Tm | Monterey Formation |
| Tp | Purisima Formation |
| Tp? | Purisima Formation, identification uncertain |
| Tsc | Santa Cruz Mudstone |
| Tsm | Santa Margarita Sandstone |
| Tsm? | Santa Margarita Sandstone, identification uncertain |
| Tsr | Rices Mudstone Member |
| Tsr? | Rices Mudstone Member, identification uncertain |
| Tst | Twobar Shale Member |
| Tv | Vaqueros Formation |
| Tvb | Basalt flows |
| Tz | Zayante Sandstone |
| dbm | Diabase and gabbro of Morrell Cutoff Road and Laurel Creek |
| sc | Silica-carbonate rock |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| atten. fault, certain | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| atten. fault, concealed | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| atten. fault, inferred | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, concealed, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| contact, inferred | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| contact, inferred, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| glauconitic marker | Mappable sedimentary horizon composed largely of glauconite pellets (³ 30%); consistently occurs at same stratigraphic level. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| normal fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| normal fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| normal fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| normal fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| s.s. fault, approx. located | Fault that has dominantly lateral slip, with opposite sides displaced either to the right or left. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| s.s. fault, certain | Fault that has dominantly lateral slip, with opposite sides displaced either to the right or left. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| s.s. fault, l.l., certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced sinistral offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| s.s. fault, r.l., approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| s.s. fault, r.l., certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| s.s. fault, r.l., concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| s.s. fault, r.l., inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| thrust fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of this fault has been inferred from probable stratigraphic and structural relationships observed at a regional scale. |
| topographic escarpment | Approximately linear steep topographic gradient separating less steep topography. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| approx. attitude | Dip and strike of planar feature approximated at a distance in the field or inferred from air photos. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. |
| flat bedding | Sedimentary layers that retain their original horizontal position were observed at this point. |
| foliation | Metamorphic foliation was observed at this point. |
| inclined lineation | Arrow and number denotes direction and amount of rake of linear feature on surface of a plane. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| ot bedding | Originally horizontal sedimentary layers were observed at this point. Evidence that the beds are overturned was observed, although that observation may not have been made at this point. |
| ot bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were overturned. |
| vert bedding | Originally horizontal sedimentary layers were observed at this point. These layers are now vertical. |
| vert bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. These layers are now vertical. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., anticline, approx. located | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., anticline, inferred, queried | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., ot anticline, approx. located | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. Evidence that the anticline is overturned was observed, although that observation may not have been made at this point. |
| f.a., ot anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. Evidence that the anticline is overturned was observed, although that observation may not have been made at this point. |
| f.a., syncline, approx. located | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, concealed | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, inferred, queried | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| Value | Definition |
|---|---|
| Jog | Gabbro cumulates |
| Joi | Intrusive complex |
| Jos | Serpentinized ultramafic rocks |
| Jos? | Serpentinized ultramafic rocks, identification uncertain |
| Jou | Ultramafic cumulates |
| Jov | Basalt, andesite, and dacite |
| Jovb | Quartz-keratophyre breccia and siliceous tuff |
| Jsl | Slate of Loma Prieta Peak |
| KJm | Mudstone (Lower Cretaceous and Upper Jurassic) |
| Kus | Sandstone and shale |
| QTf | Fluvial deposits, undivided |
| Qa | Aromas Sand |
| Qad | Dune deposits |
| Qaf | Fluvial deposits |
| Qal | Alluvium, undivided |
| Qls | Landslide deposits, undivided |
| Qoa | Older alluvium, undivided |
| Qof | Older floodplain deposits |
| Qpf | Alluvial fan deposits (Pleistocene) |
| Tbm | Mudstone (late Eocene) |
| Tbu | Undivided sandstone and shale |
| Tcm | Mottled mudstone and sandstone of Mount Chual |
| Tcm? | Mottled mudstone and sandstone of Mount Chual, identification uncertain |
| Tcms | Sandstone lenses |
| Tlm | Siliceous mudstone |
| Tlm? | Siliceous mudstone, identification uncertain |
| Tls | Sandstone and mudstone |
| Tme | Shale and sandstone of Highland Way |
| Tms | Monterey Shale |
| Tp | Purisima Formation |
| Tp? | Purisima Formation, identification uncertain |
| Tsr | Rices Mudstone Member |
| Tsr? | Rices Mudstone Member, identification uncertain |
| Tst | Twobar Shale Member |
| Tt | Temblor Sandstone |
| Tv | Vaqueros Formation |
| Tz | Zayante Sandstone |
| ch | Chert blocks |
| dbc | Diabase of Corralitos Creek |
| dbc? | Diabase of Corralitos Creek, identification uncertain |
| fm | Melange of the Central belt |
| fm? | Melange of the Central belt, identification uncertain |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fpl | Foraminiferal limestone |
| fpt | Siliceous radiolarian-bearing tuff |
| fpv | Volcanic rocks |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| atten. fault, certain | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| atten. fault, concealed | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| atten. fault, concealed, queried | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| atten. fault, inferred, queried | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| conglomeratic marker | Mappable sedimentary unit composed of pebble to boulder-size clastic material; recognizable as distant horizon. |
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, inferred, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| glauconitic marker | Mappable sedimentary horizon composed largely of glauconite pellets (³ 30%); consistently occurs at same stratigraphic level. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| marker bed | Mappable sedimentary horizon with known stratigraphic position, having distinct lithologic attributes. |
| normal fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| normal fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| normal fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| normal fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| photo lineament | Linear physiographic feature, delineated by alignment of topographic features, i.e., offsets or alignments of drainages, gullys, ridges, valley fronts, scarps or steps in topography. They are generally delineated from aerial photographs. They are inferred to be related to faulting, although are seldom checked in the field. |
| s.s. fault, r.l., approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| s.s. fault, r.l., certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| s.s. fault, r.l., concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| s.s. fault, r.l., inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced dextral offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| thrust fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| thrust fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| thrust fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| thrust fault, inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| thrust fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| topographic escarpment | Approximately linear steep topographic gradient separating less steep topography. |
| Value | Definition |
|---|---|
| approx. attitude | Dip and strike of planar feature approximated at a distance in the field or inferred from air photos. |
| axial trend, small anticline | Line delineates trend direction of small anticline. |
| axial trend, small anticline_ | Line delineates trend direction of small anticline. |
| axial trend, small syncline | Line delineates trend direction of small syncline. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. |
| complex folds | Symbol denotes axial trend and plunge direction(s) of outcrop-scale folds. |
| complex folds_ | Symbol denotes axial trend of outcrop-scale folds. |
| fold axis dip | Arrow and number define direction and degree of inclination of axial plane of fold. |
| foliation | Metamorphic foliation was observed at this point. |
| inclined lineation | Arrow and number denotes direction and amount of rake of linear feature on surface of a plane. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| lava flow attitude, w/tops | Ball on symbol denotes that top of flow unit is known from texture or pillow surface. |
| ot bedding | Originally horizontal sedimentary layers were observed at this point. Evidence that the beds are overturned was observed, although that observation may not have been made at this point. |
| ot bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were overturned. |
| vert bedding | Originally horizontal sedimentary layers were observed at this point. These layers are now vertical. |
| vert bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. These layers are now vertical. |
| vert foliation | Symbol denotes that foliation in rock is vertical. |
| vert lava flow or dike or sill | Symbol denotes that volcanic flow or dike or sill is vertical. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., antiform, inferred, queried | Surface denotes axial trend of anticlinal warp in penetratively sheared rocks. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., anticline, inferred | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., anticline, inferred, queried | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., ot syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. Evidence that the syncline is overturned was observed, although that observation may not have been made at this point. |
| f.a., ot syncline, concealed | The surface trace of the axis of an syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. Evidence that the syncline is overturned was observed, although that observation may not have been made at this point. |
| f.a., syncline, approx. located | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, concealed | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, inferred | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, inferred, queried | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| Value | Definition |
|---|---|
| H2O | water |
| Jos | Serpentinized ultramafic rocks |
| Jos? | Serpentinized ultramafic rocks, identification uncertain |
| Qal | Alluvium, undivided |
| Qhb | Basin deposits |
| Qhc | Stream Channel deposits |
| Qhf | Alluvial fan deposits (Holocene) |
| Qhl | Levee deposits |
| Qls | Landslide deposits, undivided |
| Qpf | Alluvial fan deposits (Pleistocene) |
| am | Amphibolite blocks |
| ch | Chert blocks |
| fm | Melange of the Central belt |
| fm? | Melange of the Central belt, identification uncertain |
| fmc | Radiolarian chert |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fms? | Sandstone (Upper and (or) Lower Cretaceous), identification uncertain |
| fmv | Basaltic volcanic rocks |
| fpl | Foraminiferal limestone |
| fpv | Volcanic rocks |
| fpv? | Volcanic rocks, identification uncertain |
| sc | Silica-carbonate rock |
| sc? | Silica-carbonate rock, identification uncertain |
| v | Basaltic volcanic rock blocks |
| Value | Definition |
|---|---|
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, inferred, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| photo lineament | Linear physiographic feature, delineated by alignment of topographic features, i.e., offsets or alignments of drainages, gullys, ridges, valley fronts, scarps or steps in topography. They are generally delineated from aerial photographs. They are inferred to be related to faulting, although are seldom checked in the field. |
| thrust fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| thrust fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| approx. attitude | Dip and strike of planar feature approximated at a distance in the field or inferred from air photos. |
| axial trend, small anticline | Line delineates trend direction of small anticline. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. |
| foliation | Metamorphic foliation was observed at this point. |
| joint | Surface of fracture or parting, with no displacement, was observed here. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| H2O | water |
| Jog | Gabbro cumulates |
| Jos | Serpentinized ultramafic rocks |
| KJm | Mudstone (Lower Cretaceous and Upper Jurassic) |
| Kuc | Conglomerate (Upper Cretaceous) |
| Kus | Sandstone and shale |
| Kus? | Sandstone and shale, identification uncertain |
| PP | Percolation pond |
| Qal | Alluvium, undivided |
| Qhc | Stream Channel deposits |
| Qhf | Alluvial fan deposits (Holocene) |
| Qhfp | Floodplain deposits |
| Qhl | Levee deposits |
| Qls | Landslide deposits, undivided |
| Qpf | Alluvial fan deposits (Pleistocene) |
| Qpf? | Alluvial fan deposits (Pleistocene), identification uncertain |
| Qt | Alluvial terrace deposits, undivided |
| Qt? | Alluvial terrace deposits, undivided, identification uncertain |
| Tcm | Mottled mudstone and sandstone of Mount Chual |
| Tcm? | Mottled mudstone and sandstone of Mount Chual, identification uncertain |
| Tls | Sandstone and mudstone |
| Tls? | Sandstone and mudstone, identification uncertain |
| Tme | Shale and sandstone of Highland Way |
| Tms | Monterey Shale |
| Tp | Purisima Formation |
| Tt | Temblor Sandstone |
| Ttv | Volcanic and intrusive rocks |
| Tus | Unnamed sandstone |
| af | Artificial fill |
| bs | Blueschist blocks |
| cg | Conglomerate block |
| ch | Chert blocks |
| fm | Melange of the Central belt |
| fm? | Melange of the Central belt, identification uncertain |
| fmc | Radiolarian chert |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fmv | Basaltic volcanic rocks |
| fpl | Foraminiferal limestone |
| fpv | Volcanic rocks |
| fpv? | Volcanic rocks, identification uncertain |
| mdi | Metadiorite block |
| sc | Silica-carbonate rock |
| v | Basaltic volcanic rock blocks |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| atten. fault, certain | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| atten. fault, concealed | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| atten. fault, inferred, queried | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, concealed, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| contact, inferred, queried | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the contact is inferred from structural and stratigraphic relationships observed elsewhere. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| normal fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| normal fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| normal fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| normal fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| photo lineament | Linear physiographic feature, delineated by alignment of topographic features, i.e., offsets or alignments of drainages, gullys, ridges, valley fronts, scarps or steps in topography. They are generally delineated from aerial photographs. They are inferred to be related to faulting, although are seldom checked in the field. |
| thrust fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| thrust fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| thrust fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| thrust fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| axial trend, small anticline | Line delineates trend direction of small anticline. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were upright. |
| complex folds | Symbol denotes axial trend and plunge direction(s) of outcrop-scale folds. |
| fold axis dip | Arrow and number define direction and degree of inclination of axial plane of fold. |
| foliation | Metamorphic foliation was observed at this point. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| lava flow attitude, w/tops | |
| ot bedding | Originally horizontal sedimentary layers were observed at this point. Evidence that the beds are overturned was observed, although that observation may not have been made at this point. |
| ot bedding w/tops | Originally horizontal sedimentary layers were observed at this point. In addition, a geopedal indicator was observed that showed the beds were overturned. |
| vert bedding | Originally horizontal sedimentary layers were observed at this point. These layers are now vertical. |
| vert foliation | Symbol denotes that foliation in rock is vertical. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., antiform, certain | Surface denotes axial trend of anticlinal warp in penetratively sheared rocks. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., antiform, concealed | Surface denotes axial trend of anticlinal warp in penetratively sheared rocks. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., antiform, inferred | Surface denotes axial trend of anticlinal warp in penetratively sheared rocks. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., anticline, inferred | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., anticline, inferred, queried | The surface trace of the axis of an anticline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| f.a., syncline, approx. located | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, concealed | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, concealed, queried | The surface trace of the axis of a syncline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| f.a., syncline, inferred | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, inferred, queried | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
| Value | Definition |
|---|---|
| GP | Gravel pit |
| H2O | water |
| Joi | Intrusive complex |
| Jos | Serpentinized ultramafic rocks |
| Jov | Basalt, andesite, and dacite |
| Jssp | Sedimentary serpentinite |
| Kuc | Conglomerate (Upper Cretaceous) |
| Kuc? | Conglomerate (Upper Cretaceous), identification uncertain |
| Kus | Sandstone and shale |
| MD | Mine dump |
| PP | Percolation pond |
| QTsc | Santa Clara Formation |
| QTsc? | Santa Clara Formation, identification uncertain |
| Qal | Alluvium, undivided |
| Qhb | Basin deposits |
| Qhc | Stream channel deposits |
| Qhf | Alluvial fan deposits (Holocene) |
| Qhl | Levee deposits |
| Qls | Landslide deposits, undivided |
| Qpf | Alluvial fan deposits (Pleistocene) |
| Tcm | Mottled mudstone and sandstone of Mount Chual |
| Tcml | Limestone |
| Tls | Sandstone and mudstone |
| Tms | Monterey Shale |
| Tt | Temblor Sandstone |
| Ttv | Volcanic and intrusive rocks |
| af | Artificial fill |
| am | Amphibolite blocks |
| bs | Blueschist blocks |
| ch | Chert blocks |
| fm | Melange of the Central belt |
| fm? | Melange of the Central belt, identification uncertain |
| fmc | Radiolarian chert |
| fmc? | Radiolarian chert, identification uncertain |
| fms | Sandstone (Upper and (or) Lower Cretaceous) |
| fms? | Sandstone (Upper and (or) Lower Cretaceous), identification uncertain |
| fmv | Basaltic volcanic rocks |
| fmv? | Basaltic volcanic rocks, identification uncertain |
| fpl | Foraminiferal limestone |
| fpv | Volcanic rocks |
| fpv? | Volcanic rocks, identification uncertain |
| sc | Silica-carbonate rock |
| v | Basaltic volcanic rock blocks |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| atten. fault, certain | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| atten. fault, concealed | Fault at low angle to bedding, interpreted as low-angle normal fault, double hachures on down-dropped (upper plate) side. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| contact, approx. located | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| contact, certain | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| contact, concealed | Boundary between two mapped units that retains the original depositional or intrusive relationship (i.e. not faulted). The contact is obscured by overlying map units, so it is not well-located as described in positional accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced relative offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| map boundary | Edge of the mapped area. Used primarily to bound polygons at the edge of the map database. The location of the boundary is well located as described in Positional_Accuracy. |
| normal fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced normal offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, approx. located | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 2 mm at map scale (1:24,000) or within about 48 meters on the ground. |
| thrust fault, certain | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| thrust fault, concealed | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| thrust fault, concealed, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault is obscured by overlying mapped units, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. |
| thrust fault, inferred, queried | Structural boundary between mapped units or structural discontinuity within a mapped unit that has experienced thrust offset between the rock bodies on either side of the fault. The fault has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fault is inferred from structural and stratigraphic relationships observed elsewhere. |
| water boundary | The edge of a mapped body of water. This line is derived from the base map, and therefore is well-located as described in Positional_Accuracy. |
| Value | Definition |
|---|---|
| approx. attitude | Dip and strike of planar feature approximated at a distance in the field or inferred from air photos. |
| bedding | Originally horizontal sedimentary layers were observed at this point. |
| foliation | Metamorphic foliation was observed at this point. |
| lava flow or dike attitude | Symbol denotes dip and strike of volcanic flow or dike. |
| vert bedding | Originally horizontal sedimentary layers were observed at this point. These layers are now vertical. |
| vert foliation | Symbol denotes that foliation in rock is vertical. |
| vert lava flow or dike or sill | Symbol denotes that volcanic flow or dike or sill is vertical. |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 90 |
| Units: | degrees |
| Resolution: | 1 |
| Range of values | |
|---|---|
| Minimum: | 0 |
| Maximum: | 359 |
| Units: | degrees |
| Resolution: | 1 |
| Value | Definition |
|---|---|
| f.a., antiform, certain | Surface denotes axial trend of anticlinal warp in penetratively sheared rocks. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, certain | The surface trace of the axis of an anticline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., anticline, concealed | The surface trace of the axis of an anticline. The axis is obscured by overlying mapped units, so it is not well located as described in Positional_Accuracy, but the location is constrained to be within about 5 mm at map scale (1:24,000) or within about 120 meters on the ground. |
| f.a., syncline, certain | The surface trace of the axis of a syncline. The axis has been observed or is closely constrained, so it is well-located as described in Positional_Accuracy. |
| f.a., syncline, inferred, queried | The surface trace of the axis of a syncline. The axis has not been observed, so it is not well-located as described in Positional_Accuracy, but the location is constrained to be within about 10 mm at map scale (1:24,000) or within about 240 meters on the ground. The existence of the fold is inferred from structural and stratigraphic relationships observed elsewhere. |
The geology of this area was mapped by R. J. McLaughlin, J. C. Clark, E. E. Brabb, and E. J. Helley between 1988 and 1996; part of the Mt. Madonna quadrangle was mapped by C. J. Colon from 1991-1992. The geology of the New Almaden area is partly compiled from Bailey and Everhart, 1964. The geology along the San Andreas fault is partly incorporated from Sarna-Wojcicki and others, 1975 and from U. S. Geological Survey Staff, 1989.
Numerous scientists within the U.S. Geological Survey and from academia, have contributed to this database:
Critical paleontologic support was provided by: K. McDougall-Reid and Richard Pierce (deceased), Tertiary benthic foraminifers; D. Bukry, Tertiary nannofossils; J. Barron, Tertiary diatoms; C. Powell, W. Addicott, and J. Vedder, Tertiary macrofossils; W. V. Sliter (deceased), Mesozoic foraminifers; B. Murchey, Y. Isozaki, and I. Hattori, Mesozoic radiolaria; and W. Elder and D.L. Jones, Mesozoic macrofossils.
Isotopic data for age and provenance determinations were provided by R. Kistler and D. Champion, Rubidium and Strontium; J. Nakata, D. Sorg and P. Russell, K-Ar and Ar-Ar radiometric ages; and J. Wooden, U-Pb radiometric age.
A fission track age investigation, conducted in the map region in 1992-1994 by T. Dumitru, R. BŸrgmann, and Ramon Aerosmith, of Stanford University, in cooperation with the senior author, has contributed substantially to an understanding of the structural history of this area.
The senior author (McLaughlin) also wishes to acknowledge the following scientists for their collaborative and cooperative work, that has strongly influenced interpretations of the geology and crustal structure of the map region: R. Jachens, A. Griscom and V. Langenheim (U.S.G.S.), modeling of gravity and aeromagnetic data; R. BŸrgmann (Stanford, now at U.C. Berkeley), geodetic data; C.M. Wentworth and R.G. Stanley (U.S.G.S.), regional geology; R. Wells, D. Ponti, C. Prentice, D. Schwartz, S. Ellen, and K. Schmidt, (all at the U.S.G.S.), and W. Cotton ( W. Cotton and Associates), detailed work on surface deformation and active fault relationships following the 1989 Loma Prieta earthquake.
The authors wish to acknowledge the many owners of large land parcels and ranches in rural areas of Santa Clara and Santa Cruz Counties, who have cooperated with these mapping investigations by providing access to their properties and showing interest in the work. We also thank the following private and public agencies for their cooperation in allowing access and gate keys to their properties, including the San Jose Water Company; Mid- Peninsula Open-Space District; and the Santa Clara County Park system.
We also wish to thank the California Division of Forestry, particularly CDF Burrel Fire Station of Santa Cruz County, for providing lodging to the senior author (McLaughlin) in the course of mapping investigations.
This digital database was compiled in ARC/INFO, a commercial G.I. S.(ESRI). The digital compilation was done using the 1996 version 3.0 of the menu interface ALACARTE (originally published as version 1.0 by Fitzgibbon and Wentworth, 1991). The digitization of geologic contacts, development and integration of various data sets into the digital map database were largely supervised by C. M. Wentworth (1988-1997). Numerous individuals have compiled and edited parts of the digital files for this publication at different times, including T. A. Lindquist (1988), P. Showalter (1989-1990), C. E. Nelson (1994), L. Gerhardt ( 1996), C. R. Randolph, T. E. May, and J. L. Minnick (1996-1998), and Z. C. Valin (1996-2001). The digital geology was initially compiled as a part of the geologic map database for the San Jose, California 1:100,000-scale quadrangle (Wentworth and others, unpublished, 1999) but the maps are herein released at 1:24,000.
Geologic mapping was at a scale of 1:24,000, which is therefore the scale of maximum resolution. Enlargement of these maps to scales substantially less than 1:24,000 is here considered inappropriate.
Technical reviews of this report were provided by P. Stone ( Western Earth Surface Processes Team, U.S.G.S.) and by M. C. Blake, Jr., (Emeritus). R. Graymer (Western Earth Surface Processes Team, U.S.G.S.) reviewed the database. Technical editing of this report for publication by the U.S. Geological Survey was provided by J. Zigler, and preparation of the database website was by R. Koch and C. Donlin (all at Western Publications Unit, U.S.G.S.).
Note: Authorship of the geology of this publication resides in the first five names in the author list in the order given. The last nine names starting with Z.C. Valin, are the digital database authors in the order given.
This database and accompanying plot files depict the distribution of geologic materials and structures at a regional (1:24,000) scale. The report is intended to provide geologic information for the regional study of materials properties, earthquake shaking, landslide potential, mineral hazards, seismic velocity, and earthquake faults. In addition, the report contains new information and interpretations about the regional geologic history and framework. However, the regional scale of this report does not provide sufficient detail for site development purposes. In addition, this map does not take the place of fault-rupture hazard zones designated by the California State Geologist (Hart and Bryant, 1997). Similarly, the database cannot be substituted for comprehensive maps that systematically identify and classify landslide hazards.
Are there legal restrictions on access or use of the data?Access_Constraints: None
Use_Constraints:Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited for a scale of 1:24,000 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:24,000 will not yield greater real detail, although it may reveal fine- scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this publication has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.
| Data format: | Plotfiles, one for each map sheet, one for the pamphlet, one for this database pamphlet, two for the cross section sheets, and one for the explanation sheet. in format PDF (version 1.3) Adobe Acrobat PDF files, v. 3.0 |
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| Network links: |
http://pubs.usgs.gov/mf/2002/2373/mf2373pdf.tgz |
| Data format: | Geologic units and structural features along with supporting documentation in format ARCE (version 7.2.1) Size: 17 |
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| Network links: |
http://pubs.usgs.gov/mf/2002/2373/mf2373db.tgz |
