|NECB||New England Coastal Basin|
|CONN||Connecticut, Housatonic, and Thames River Basins|
|STL_HUD||St. Lawrence-Hudson River Basins|
|Avalon Belt||Avalon Belt terrane, Avalon Province
Localized in eastern Massachusetts, Rhode Island, and coastal Connecticut. Principally Precambrian Z granite and granitic gneiss and metasedimentary rocks of Precambrian Z to Ordovician age. Intruded by Ordovician to Devonian granites. Cretaceous sediments and thick areas of Quaternary glacial sediments occur in southern coastal areas.
|Bronson Hill Sequence||Bronson Hill Sequence terrane
Triassic to Jurassic age sediments and basalt flows deposited in localized rift basins in from Connecticut to western New Hampshire and northern Maine. Principally Ordovician igneous and metavolcanic rocks overlain by Ordovician to Devonian metasedimentary rocks. Sulfidic schists and mafic rocks are common. Intruded by Devonian granites.
|Coastal Maine||Coastal Maine terrane
Localized along northeastern coastal Maine. Principally PreCambrian Z to Silurian metasedimentary and metavolcanic rocks intruded by Devonian granites.
|Eugeosyncline Sequence||Eugeosyncline Sequence terrane
Includes slates and pelitic metamorphic rocks in the Taconic Range and schists east of the Grenville Belt. Principally Cambrian to Ordovician pelitic metasedimentary rocks, including metavolcanic layers and lenses of ultramafic rocks.
|Grenville Belt||Grenville Belt terrane
Includes areas of Grenville Basement (PreCambrian Y metamorphic rocks) in western Connecticut, Massachusetts, and Vermont. Principally granitic gneiss and metasedimentary rocks. Includes some Cambrian metasedimentary rocks deposited on Precambrian basement.
|Grenville Shelf Sequence||Grenville Shelf Sequence terrane
Principally carbonate rocks and other metasedimentary rocks deposited in a carbonate shelf sequence overlying Grenville basement in western Connecticut, Massachusetts, and Vermont.
|Mesozoic Basin||Mesozoic Basin terrane
Triassic to Jurassic age sediments and basalt flows deposited in localized rift basins in central Connecticut and Massachusetts. Intruded by Jurassic diabase and basalt dikes.
|NH - Maine Sequence||NH-ME terrane, New Hampshire-Maine Sequence
Covers eastern Connecticut, central Massachusetts, eastern New Hampshire, and central Maine. Principally Silurodevonian metasedimentary rocks and Silurodevonian and younger igneous rocks, principally granite.
|Narragansett Basin||Narragansett basin terrane
Permian conglomerates and other sediments deposited in fault-bounded basins in Avalon province rocks in southeastern Massachusetts and Rhode Island.
|Waits River-Gile Mt. S||Waits River Gile Mt. Sequence terrane
Principally Devonian variably-calcareous metasedimentary rocks in eastern Vermont and the northern Connecticut valley in Massachusetts, intruded by Devonian granite.
|B||Bronson Hill Sequence|
|C||Waits River-Gile Mt. Sequence|
|M||NH - Maine Sequence|
|S||Grenville Shelf Sequence|
|Basin Sedimentary||Sediments deposited in fault-bounded basins of Permian and younger age.|
|Calcpelite||Calcareous clastic and metaclastic rocks containing approximately 15-45% carbonate minerals.|
|Carbonate Rocks||General rock composition carbonate rock, includes limestone, dolomite, and marble with mixed calc-silicate rocks.|
|Granites||General rock composition granite.|
|Mafic Rocks||General rock composition mafic igneous rocks and their metamorphic equivalents.|
|Metamorphic Rocks Undivi||Metamorphic rocks other than carbonate rocks, calcpelite, or mafic rocks.|
|Unconsolidated Sediments||Unconsolidated or poorly consolidated sediments of tertiary and younger age.|
|Water||Inland freshwater body|
|Alkali Granite (White Mt)||Alkali granites associated with the White Mountain Plutonic-Volcanic suite (Lyons and others, 1997. Includes granitic rocks in the New England-Quebec and White Mountain igneous provinces of McHone and Butler (1984).|
|Avalon Granite||Granite of Precambrian Z age in the Avalon province.|
|Calcpelite||Calcareous clastic and metaclastic rocks containing Approximately 15-45% carbonate minerals.|
|Calcgranofels||Fine-grained calcareous clastic and metaclastic rocks containing calc-silicate minerals. May contain a small percentage of carbonate minerals.|
|Carbonate rocks||General rock composition carbonate rock, includes limestone, dolomite, and marble with mixed calc-silicate rocks.|
|Felsic Volcanics||Felsic volcanic rocks and mixed volcanic rocks where felsic volcanics predominate.|
|Granite, other||Granite, other than types listed below.|
|Grenville Granite||Granite of the Precambrian Y age in Grenville basement rocks.|
|Mafic Rocks||Mafic igneous rocks and their metamorphic equivalents.|
|Mesozoic Basin Sediments||Triassic-Jurassic continental sediments deposited in rift basins of Mesozoic age.|
|Metamorphic Rocks Undivi||Metamorphic rocks other than carbonate rocks, calpelite, calcgranofels, pelitic rocks, sulfidic schists, or mafic rocks.|
|Narragansett Basin Sediment||Permian continental sediments deposited in fault-bounded Permian basin.|
|Pelitic Rocks||Pelitic rocks and interbedded pelitic and sandy sediments and their metamorphic equivalents.|
|Peraluminous granite||Granite types containing primary muscovite, of Late Devonian to Carboniferous age.|
|Sulfidic Schists||Metamorphosed pelitic rocks containing sufficient pyrite and(or) pyrrhotite to develop a rusty-weathering characteristic.|
|Ultramafic Rocks||Serpentine, dunite, and other ultramafic rocks.|
|Unconsolidated Sediments||Unconsolidated and poorly consolidated sediments of tertiary or younger age.|
|Water||Inland bodies of fresh water.|
|0||Inland body of fresh water|
|20||Mesozoic basin sediments|
|21||Narragansett basin sediments|
|3||Metamorphic rocks, undivided|
|64||Alkali granite (White Mt)|
This includes both non-consolidated and poorly consolidated sediments, and encompasses areas in the south-coastal part of the New England study area where the bedrock is overlain by thick glacial sediments at the surface. These surficial glacial deposits are the primary aquifer for these areas.
|-9999||(surface water body)|
|11||limestone, dolomite, and carbonate-rich clastic rocks; may include fine-grained non-calcareous clastic rocks|
|12||marble; may include some calc-silicate rock|
|13||calcareous clastic and metaclastic rocks containing approximately 15 to 45% carbonate minerals|
|21||tan and red mudstone and shale; may include sandstone; locally contains minor carbonate or gypsum|
|22||interbedded mudstone, shale, and siltstone; may contain sandstone|
|23||sandstone and interbedded sandstone and conglomerate; may contain siltstone, shale, and mudstone|
|31||slate and graywacke|
|32||pelitic schist and phyllite, may include granofels|
|33||mixed schist, granofels; and gneiss|
|34||quartzose metasandstone, quartzite, quartz granofels, and quartzose gneiss|
|42||greenstone, lower greenschist facies metabasalt, and schistose mafic rock with minor dispersed carbonate (Mg-rich)|
|43||amphibolite and layered mafic gneiss; may be mixed with other lesser lithologies such as felsic volcanics and metaclastic rocks|
|44||massive mafic rocks; includes gabbro, diorite, monzodiorite, and diabase|
|50||ultramafic rocks; includes serpentinites, dunites, peridotites, and tremolite-talc schists associated with other ultramafic rocks|
|61||granitoid rocks; includes granite, quartz monzonite, granodiorite, trondhjemite, and equivalent gneiss|
|62||quartz-poor plutonic rocks; includes syenite, monzonite, quartz syenite, and anorthosite|
|70||nepheline syenite; includes feldspathoid-bearing syenitic rocks and volcanic rocks|
|u||unit is undifferentiated|
|c||unit may contain small or variable amounts of carbonate minerals|
|cs||unit may contain small or variable amounts of carbonate minerals and minor amounts of pyrite, pyrrhotite, or both|
|g||unit contains variable amounts of graphite or organic materials|
|gc||unit may contain variable amounts of carbonate minerals and organic materials|
|gs||unit may contain minor amounts of pyrite, pyrrhotite, or organic materials, sufficient to cause a rusty-weathering characteristic.|
|s||unit may contain minor amounts of pyrite, pyrrhotite, or both|
|v||felsic volcanics associated within granite intrusions|
|Codeset Name:||Lithologic units from state maps|
|Codeset Source:||File Bedrock.dbf in this data set|
|Water||Inland freshwater body|
|Codeset Name:||Lithologic units from state maps|
|Codeset Source:||File Bedrock.dbf in this data set|
|Range of values|
|Range of values|
Individuals involved in the creation of the final New England Lithology (NE_LITH), CONN, and NECB coverages are listed as follows:
New England Lithology (final Coverage NE_LITH):
Gilpin R. Robinson, Jr.: U.S. Geological Survey, Reston, Va. Primary developer of the classification scheme. Preparation of source materials and information for combining the coverages into a general representation of New England Lithology.
Katherine E. Kapo: U.S. Geological Survey, Reston, Virginia. Assisted in editing the coverage linework and attributes, creation of the final "New England Lithology" version, and compilation of the final metadata.
Joseph D. Ayotte: U.S. Geological Survey, Pembroke, New Hampshire. New England Coastal Basin NAWQA ground-water specialist; reviewed the construction of the combined coverage.
Laura Hayes: U.S. Geological Survey, Pembroke, New Hampshire. Reviewed the finalized coverage and metadata and provided corrections for the metadata and attribute table.
Gilpin R. Robinson, Jr: Preparation of source materials and compilation of lithogeochemical units for Connecticut and Massachusetts regions; primary development of lithogeochemical classification scheme.
John D. Peper: Preparation of source materials and compilation of lithogeochemical units for Vermont and New Hampshire regions; additional development of lithogeochemical classification scheme.
Peter A. Steeves: Construction, revision, quality-assurance, and documentation of the digital data layer and publication of the data layer as a digital map product.
Leslie A. DeSimone: Quality assurance, revision, and documentation of the data layer and publication of the data layer as a digital map product.
Stephen P. Garabedian: Connecticut River NAWQA chief; coordinating personnel and funding, planning, oversight, and review of the data layer
Stephen J. Grady: Connecticut River NAWQA ground-water specialist; primary user of the resulting data; planning and definition of water quality issues of the NAWQA study unit for use in development of the data layer and oversight of the initial data-layer construction phases.
Robert Sava, Jr: Digitizing and coding contributions in NH, MA, and VT
Shanon Wappel: Digitizing and coding contributions in CT
Gilpin R. Robinson, Jr.: U.S. Geological Survey, Reston, VA. Primary developer of the classification scheme. Preparation of source materials and compilation of lithogeochemical units for Maine, Massachusetts, and Rhode Island.
John D. Peper: U.S. Geological Survey, Reston, VA. Preparation of source materials and compilation of lithogeochemical units for New Hampshire; secondary developer of the lithogeochemical classification scheme.
John C. Rader: U.S. Geological Survey, Marlboro, Massachusetts. Construction, revision, quality-assurance, and documentation of the original digital data layer.
Keith W. Robinson: U.S. Geological Survey, Pembroke, New Hampshire. New England Coastal Basin NAWQA Chief; Coordination of personnel and funding, planning, oversight, and review of the data layer.
Joseph D. Ayotte: U.S. Geological Survey, Pembroke, New Hampshire. New England Coastal Basin NAWQA ground-water specialist; primary user of the resulting data; planning and definition of the water-quality issues of the NAWQA study unit for use in development of the data layer and oversight of the data layer construction phases.
Leslie A. DeSimone: U.S. Geological Survey, Marlboro, Massachusetts. Technical reviewer of original digital data layer.
Walt Bawiec: U.S. Geological Survey, Reston, Virginia. Colleague reviewer who performed technical reviews of the completed digital data set and metadata document.
Curtis Price: U.S. Geological Survey, Rapid City, South Dakota. Colleague reviewer who performed technical reviews of the completed digital data set and metadata document.
Sarah M. Flanagan: U.S. Geological Survey, Pembroke, New Hampshire. Edited the coverage and assisted in compilation and editing the metadata.
Laura Hayes: U.S. Geological Survey, Pembroke, New Hampshire. Created plots of the CONN lithogeochemical coverage and the NECB lithogeochemical coverage so that consistency along the study-unit border could be checked. Corrected the shift in the Massachusetts portion of the coverage. Assisted in compilation and editing of the NECB metadata.
This geologic characterization provides a framework to interpret regional geochemistry and habitat characteristics in relation to bedrock lithology and geologic provinces that share common features. The lithogeochemical data layer combines and extends data previously compiled for the U.S. Geological Survey National Water Quality Assessment Program (NAWQA) study areas of the New England Coastal Basin (NECB), and the Connecticut, Housatonic, and Thames River Basins (CONN). The coverage provides digital geologic information that may be applied to the analysis of water-quality characteristics of surface water and shallow ground water, and soil and stream sediment characteristics based on bedrock lithogeochemistry.
The geologic characterization provided in this classification is intended to portray significant bedrock geologic features that influence stream sediment and soil chemistry and water quality.
"Near-surface bedrock" in this report refers to lithified materials covered by no more than about 60 feet of overlying unconsolidated surficial materials. The thickness of Quaternary sediments overlying bedrock is generally less than 60 feet in the New England states (Soller, 1993).
The bedrock units shown on the source maps were grouped and generalized for this compilation. Consequently this map will show fewer geologic units and less detail than the state geologic maps from which the information was drawn.
A few areas have been modified from those shown on the state maps, for example, additional units portrayed by Smoot (1991) are shown in the Hartford Basin area of Connecticut and Massachusetts and mismatched contacts have been adjusted along state borders.
Based on the geologic map compilation scales, mismatches of some unit contacts across state boundaries, and the positioneal uncertainty of the source digital files relative to the published geologic maps, the spatial accuracy of this compilation is estimated as 1.5 km.
To the degree that surficial materials are related to their proximal bedrock source, the variations in bedrock geology also provide guidelines to the expected variation in the properties and chemistry of surficial materials and surface waters. In glaciated areas, such as New England, the mineralogy of tills and some stratified drift is related to adjacent bedrock units, and bedrock geology has been used to help define their chemical character (Bailey and Hornbeck, 1992). A lithogeochemical framework similar to that provided in this report has been used to define correlations between groundwater chemistry and bedrock geology (Grady and Mullaney, 1988; Ayotte and others, 1999). Groundwater chemistry for alkalinity, pH, Ca, Mg, Na, silica, and radon in surficial aquifers sampled from wells up to 60 feet in depth in surficial aquifers have been shown to correlate with groups of lithology of the underlying bedrock (Grady and Mullaney, 1988). Groundwater chemistry for pH, iron, manganese, and arsenic in fractured crystalline bedrock aquifers sampled from wells up to 500 feet in depth differ by bedrock lithology groups (Ayotte and others, 1999; Ayotte and others, 2003).
The lithogeochemical characterization in these data have been put to use analyzing water-quality characteristics in studies by Grady and Mullaney (1998) and Ayotte and others (2003).
Are there legal restrictions on access or use of the data?
Although these data have been used by the U.S. Department of the Interior, U.S. Geological Survey, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.
The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
|Data format:||Lithogeochemical units and geologic provinces in format ARCE (version 8.3) Size: 14|
|Data format:||Lithogeochemical units and geologic provinces in format Shapefile (version 1.0) Size: 14|