Online Links:
| Value | Definition |
|---|---|
| atten. fault, approx. located | Attenuated fault whose position is not precisely known |
| atten. fault, certain | Observed attenuated fault |
| atten. fault, concealed | Concealed attenuated fault whose position is inferred |
| fault, approx. located | Fault whose position is not precisely known |
| fault, certain | Observed fault |
| fault, concealed | Concealed fault whose position is inferred |
| fault, concealed, queried | Concealed fault whose position is questionable |
| fault, inferred | Fault whose position is inferred |
| fault, inferred, queried | Fault whose position is inferred and questionable |
| s.s. fault, r.l., approx. located | Right-lateral strike-slip fault whose position is not precisely known |
| s.s. fault, r.l., certain | Observed right-lateral strike-slip fault |
| s.s. fault, r.l., concealed | Concealed right-lateral strike-slip fault |
| thrust fault, approx. located | Thrust fault whose position is not precisely known |
| thrust fault, certain | Observed thrust fault |
| thrust fault, concealed | Concealed thrust fault whose position is inferred |
| thrust fault, inferred | Thrust fault whose position is inferred |
| Value | Definition |
|---|---|
| Castro Valley | |
| Chabot | |
| Fremont | |
| San Leandro | |
| San Pablo | |
| creeping | |
| east boundary | |
| (blank) | unknown |
| Value | Definition |
|---|---|
| JKfm | Franciscan melange (Late Jurassic and Early Cretaceous) |
| JKfn | Sandstone of Novato Quarry (Late Cretaceous) |
| JKf | Undivided rocks of the Franciscan Complex (Late Jurassic to Late Cretaceous) |
| sp | Serpentinite - Coast Range Ophiolite (Jurassic) |
| Jgb | Gabbro - Coast Range Ophiolite (Jurassic) |
| Jb | Massive basalt and diabase - Coast Range Ophiolite (Jurassic) |
| Jpb | Pillow basalt, basalt breccia, and minor diabase - Coast Range Ophiolite (Jurassic) |
| Jsv | Keratophyre and quartz keratophyre (Late Jurassic) |
| JKk | Knoxville Formation (Late Jurassic and Early Cretaceous) |
| Knc | Sandstone and shale of Niles Canyon (Early Cretaceous, Albian) |
| Kjm | Joaquin Miller Formation (Late Cretaceous, Cenomanian) |
| Ko | Oakland Sandstone (Late Cretaceous, Cenomanian and/or Turonian) |
| Kcv | Unnamed sandstone, conglomerate, and shale of the Castro Valley area (Late Cretaceous, Turonian and younger(?)) |
| Ksc | Shephard Creek Formation (Late Cretaceous, Campanian) |
| Kr | Redwood Canyon Formation (Late Cretaceous, Campanian) |
| Kp | Pinehurst Shale (Late Cretaceous, Campanian) |
| Ku | Undivided, unnamed sandstone and siltstone (Cretaceous) |
| Kc | Undivided, unnamed conglomerate (Cretaceous) |
| Tas | Unnamed glauconitic sandstone (Paleocene) |
| Tps | Unnamed siltstone and sandstone (Paleocene) |
| Tes | Unnamed mudstone (Eocene) |
| Ttls | Gray, algal limestone - Tolman Formation of Hall (1958) (Eocene?) |
| Tts | Dark gray to dark greenish-gray, indistinctly bedded, glauconite bearing, medium- to coarse- grained lithic sandstone - Tolman Formation of Hall (1958) (Eocene?) |
| Tgs | Unnamed glauconitic mudstone (Oligocene(?) and Miocene) |
| Tsh | Unnamed sandstone, shale, chert, and dolomite (early Miocene) |
| Ts | Sobrante Sandstone (middle Miocene) |
| Tcc | Chert and siliceous shale member - Claremont Formation (middle to late Miocene) |
| Tcs | Sandstone and siltstone member - Claremont Formation (middle to late Miocene) |
| To | Oursan Sandstone (middle to late Miocene) |
| Tt | Tice Shale (late Miocene) |
| Tbr | Briones Formation (late Miocene) |
| Tor | Orinda Formation (late Miocene) |
| Tm | Moraga Formation (late Miocene) |
| Tst | Siesta Formation (late Miocene) |
| Tbp | Bald Peak Basalt (late Miocene) |
| Tn | Neroly Sandstone (late Miocene) |
| Tv | Unnamed volcanic rocks (late Miocene or early Pliocene) |
| Tss | Unnamed sandstone and conglomerate (Tertiary) |
| Tsk | Silver Creek Gravels of Graymer and DeVito (1993) (Pliocene) |
| QTp | Packwood Gravels of Crittenden (1951) (Pliocene and Pleistocene(?)) |
| QTl | Livermore Gravels (Pliocene and/or Pleistocene) |
| QTi | Irvington Gravels of Savage (1951) (Pliocene(?) and Pleistocene) |
| Qoa | Unnamed gravels and terrace deposits (Pleistocene) |
| Qls | Landslide deposits (Pleistocene and/or Holocene) |
| Qu | Undivided surficial deposits (Pleistocene or Holocene) |
| Qm | Manmade deposits (Holocene) |
| Value | Definition |
|---|---|
| atten. fault, approx. located | Attenuated fault whose position is not precisely known |
| atten. fault, certain | Observed attenuated fault |
| atten. fault, concealed | Concealed attenuated fault whose position is inferred |
| fault, approx. located | Fault whose position is not precisely known |
| fault, certain | Observed fault |
| fault, concealed | Concealed fault whose position is inferred |
| fault, concealed, queried | Concealed fault whose position is questionable |
| fault, inferred | Fault whose position is inferred |
| fault, inferred, queried | Fault whose position is inferred and questionable |
| s.s. fault, r.l., approx. located | Right-lateral strike-slip fault whose position is not precisely known |
| s.s. fault, r.l., certain | Observed right-lateral strike-slip fault |
| s.s. fault, r.l., concealed | Concealed right-lateral strike-slip fault |
| thrust fault, approx. located | Thrust fault whose position is not precisely known |
| thrust fault, certain | Observed thrust fault |
| thrust fault, concealed | Concealed thrust fault whose position is inferred |
| thrust fault, inferred | Thrust fault whose position is inferred |
| contact, approx. located | Contact whose position is not precisely known |
| contact, certain | Observed contact |
| contact, inferred | |
| map boundary | Boundary of mapped area |
| scratch boundary | Position of scratch boundary |
| water boundary | Boundary of a body of water |
| (blank) | unknown |
All of the geologic mapping for the Hayward fault zone is new, but we acknowledge our debt to previous workers who established the geologic framework. Data sources for geologic mapping in the fault zone within Contra Costa County are provided by Graymer, Jones, and Brabb (1994). In Alameda and Santa Clara Counties, the geologic reports by Radbruch (1969), Case (1968), Graymer and others (1994), Robinson (1956), Hall (1958), and Crittenden (1951) are especially relevant. Preliminary geologic maps by T.W. Dibblee of most of the 1:24,000 quadrangles are available in Open-File Reports of the U.S. Geological Survey (see references). The map and report by Lienkaemper (1992) provided some of the lines for the creeping strand of the Hayward fault, and they contain many references to previous work. Several students have done theses in the area; the ones by Haltenhoff (1978), Whiteley (1978), and Prowell (1974) are especially pertinent.
The purpose of this report is fivefold. 1) to demonstrate the short history of the creeping strand and to describe the structural history of the fault zone as a whole; 2) to illustrate potentially active strands within the Hayward fault zone in addition to the creeping strand defined by Lienkaemper; 3) to describe structures related to the Hayward fault zone including compressive structures; 4) to show possible Hayward - Calaveras fault connections in addition to that proposed by Andrews and others; 5) to describe rock types involved in the Hayward fault zone.
Are there legal restrictions on access or use of the data?Access_Constraints: none
Use_Constraints:
This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
This database, identified as "Geologic map of the Hayward fault zone, Contra Costa, Alameda, and Santa Clara Counties, California: A digital database," has been approved for release and publication by the Director of the USGS. Although this database 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: |
ARC/INFO Coverages Description of Coverage hfcc_um/ Geologic map of the Hayward fault zone in Contra Costra County hfal_um/ Geologic map of the Hayward fault zone in Alameda County hfsc_um/ Geologic map of the Hayward fault zone in Santa Clara County hf_um-flt/ Map of faults in the Hayward fault zone hf_dr/ Drainage base map hf_cu/ Cultural base map hf_topo/ Topographic contours base mapin format ARCE (version 6.x) Size: 18.6 |
|---|---|
| Network links: |
http://pubs.usgs.gov/of/1995/of95-597/hf_g1.tar.Z |
