Abstract: This geographic information system (GIS) data layer shows the generalized lithologic and geochemical, termed lithogeochemical, character of near-surface bedrock in the New England Coastal Basins (NECB) study area of the U.S. Geological Survey's National Water Quality Assessment (NAWQA) Program. The area encompasses 23,000 square miles in western and central Maine, eastern Massachusetts, most of Rhode Island, eastern New Hampshire and a small part of eastern Connecticut. The NECB study area includes the Kennebec, Androscogginn, Saco, Merrimack, Charles, and Blackstone River Basins, as well as all of Cape Cod. Bedrock units in the NECB study area are classified into 38 lithogeochemical units based on the relative reactivity of their constituent minerals to dissolution and the presence of carbonate or sulfide minerals. The 38 lithogeochemical units are generalized into 7 major groups: (1) carbonate-bearing metasedimentary rocks; (2)primarily noncalcareous, clastic sedimentary rocks with restricted deposition in discrete fault-bounded sedimentary basins of Mississipian or younger age; (3) primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism; (4) mafic igneous rocks and their metamorphic equivalents; (5) ultramafic rocks; (6) felsic igneous rocks and their metamorphic equivalents; and (7) unconsolidated and poorly consolidated sediments.
Purpose: The lithogeochemical data layer was compiled to provide the NECB NAWQA study area with digital geologic information that could be used in the analysis of surface- and ground-water quality. Goals of the NAWQA program are to describe the status and trends of a large representative part of the Nation's surface- and ground-water resources and to identify the natural and human factors that affect the quality of these resources (Leahy and others, 1990). The data layer presented here was intended to characterize the bedrock units in the study area in terms of mineralogic and chemical parameters relevant to water quality, such that the geologic data could be used in GIS to plan NAWQA study-unit activities, and to analyze and interpret water-quality and ecosystem conditions.
Supplemental Information: The classification scheme used was first developed as part of the USGS's study of the Connecticut, Housatonic, and Thames River Basins (CONN), an adjacent NAWQA study area (Robinson and others, 1999). The classification scheme is based on geochemical principles, previous studies of the relations among water-quality and ecosystem characteristics and rock type, and the regional geology of New England. The classification scheme and data set are intended to provide a general, flexible framework for classifying and mapping bedrock units in the study area for all types of water-quality analysis. The data set is a lithologic map that has been coded to reflect the potential influence of geology on water quality. The classification scheme provides flexibility because the user can reclassify the 38 lithogeochemical units into other groups for other types of data analysis. The bedrock units in this study area have been mapped defined by time- stratigraphic and other geologic criteria which may not be directly relevant to water quality. Bedrock units depicted on the State geologic maps are inconsistent across state boundaries in some areas (See Data_Quality_Information section of this document for explanation on how these discrepancies were addressed with the classification scheme). Thus, a study-area-wide coding scheme was developed to classify the geologic map units according to mineralogical and chemical characteristics that are relevant for water-quality investigations. Bedrock units were classified for water-quality purposes according to the chemical composition and relative susceptibility to weathering of their constituent minerals. Although weathering rates may vary, the relative stability of different minerals during weathering in moist climates is generally consistent (Robinson, 1997). However, the degree to which a rock weathers reflects the proportions of its constituent mineral as well as many other factors such as degree of induration and relative amount of mineral surfaces exposed to water through primary and secondary porosity. Thus, although largerly based on the relative stability of rock constituent minerals, the classification scheme to group bedrock units according to effects on water quality is more complex than mineral- stability sequences. Most common rock-forming minerals are only sparingly soluble, so that small amounts of highly reactive minerals can have large effects of water quality (Robinson, 1997). For example, carbonate minerals are more rapidly weathered and tend to produce higher solute concentrations in natural waters than other rock types. In contrast, granites, schists and quartzites, which are rich in alkali-feldspar, muscovites, and quartz, produce low solute concentrations because they react to a lesser degree and at slower rates than other rock types in humid temperate climates (Robinson, 1997). The lithogeochemical classification scheme used in this data set incorporates the relative stability of minerals classifications criteria such as used in previous studies, and the characteristics of bedrock geology specific to the study area (such as the presence of a discrete fault bounded sedimentary basins of Mississipian or younger age). Further description of the lithogeochemical classification scheme and the expected water- quality and ecosystem characteristics associated with each lithogeochemical unit is explained in Robinson (1997). Thirty-eight lithogeochemical units have been defined for the NECB study area based on the mineral and textural properties of the bedrock unit's constituent minerals, presence of carbonate and sulfide minerals and for some of the granitic units, relative age. The classification scheme used descriptions from State geologic maps (Osberg and others, 1985; Lyons and others, 1997; Zen and others, 1985;Hermes and others, 1994; and Rogers, 1985) of the lithology, mineralogy, and weathering characteristics of the bedrock units. For example, "rusty-weathering" serves as an indicator of sulfidic-bearing bedrock units (Robinson, 1997). Carbonate and sulfide minerals predominate in the classification scheme because these highly reactive minerals have a disproportionately large effect on water chemistry compared to other minerals commonly found in the rocks of this region. In the Maine data set, information about metamorphic grade was also used to classify bedrock units. A digital data layer of generalized regional metamorphic zones (Guidotti, 1985, shown in Osberg and others,1985), was obtained from the Maine Geological Survey. This layer was intersected with the digital bedrock geology to determine the regional metamorphic grade of each polygon in the bedrock geology data layer. Polygons lying within two metamorphic zones were split at the metamorphic-zone boundary. Metamorphic grade and geochemical composition of the protolith (pre-metamorphism source rock) were used to classify polygons into lithogeochemical units. For example, bedrock units with protoliths of "limestone and(or) dolostone" were classified as "limestone, dolomite, and carbonate-rich clastic sediments" (lithogeochemical unit "11u") in areas of none or weak regional metamorphism and as "marble, may include some calc-silicate rock" (lithogeochemical unit "12u") in areas of greenschist facies or high grade metamorphism. The 38 lithogeochemical units defined for the NECB study area result from the combination of a lithology code (numeric) with a modifier code (alphabetic). There are 17 lithology codes that represent the influences on water chemistry of lithology, metamorphic grade, and geologic setting. Each bedrock unit is assigned one of 17 lithology codes based on the description of the bedrock unit from the State bedrock geologic maps. There are 13 modifier codes used to identify minor amounts of carbonate and(or) sulfide minerals, and subdivide granitic units into subgroups based on their chemical and mineral characteristics and relative age. A description of the 38 lithogoechemical units in the NECB study area and their potental effects on water quality can be found in the Supplemental_Information section of this document. The 38 lithogeochemical units are generalized into 7 major groups that share similarities in overall geochemistry and lithology: (1) carbonate-bearing metasedimentary rocks; (2) primarily noncalcareous, clastic sedimentary rocks deposited in fault-bounded sedimentary basins of Mississipian or younger age; (3) primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism; (4) mafic igneous rocks and their metamorphic equivalents; (5) ultramafic rocks; (6) felsic igneous rocks and their metamorphic equivalents; and (7) unconsolidated and poorly consolidated sediments. Major group 7 encompasses areas in the south-coastal part of the NECB 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. An example of how this data set has been used in study design strategies and in analyzing water-quality characteristic by lithogeochemical units and major groups is provided in Ayotte and others (1999). The bedrock units shown on the individual State maps for the NECB were classified according to a lithogeochemical scheme modified from Robinson and others (1999). Specifically, the modification included the subdivision of granitic bedrock units into additional lithogeochemical units with modifying attributes to indicate relative age. However, this modification to the classification system is evident in the lithogeochemical units. Thus, the CONN and the NECB data set can be readily merged together to create a larger regional product with these difference being more frequent when the data set is viewed with the lithogeochemical units showing and less frequent when the data set is viewed with the major groups showing. Overall, the bedrock units in the two study units are classified in a consistent manner to a create regional product that can be used to evaluate the influences of bedrock geology on water-quality characteristics. Quality Assurance procedures: The scientific content of this digital data set underwent technical review by two USGS scientists who have knowledge of the regional geology,and GIS and spatial-data production. The data set was evaluated on positional accuracy, contextual accuracy, attribute accuracy, and topological consistency. References_Cited Ayotte, J.P., Nielsen, M.G., Robinson, G.R., Jr., Moore, R,B., 1999, Relation of arsenic, iron, and manganese in ground water to aquifer type, bedrock lithogeochemistry, and land use in the New England Coastal Basins, U. S. Geological Survey Water-Resources Investigative Report 99-4162, 61 p. Guidotti, C.V., 1985, Generalized map of regional metamorphic zones: in Osberg, P.H., and others: Augusta, Maine, Maine Geological Survey, 1 map sheet, 1:1,600,000. Hermes, O.D., Gromet, L.P., Murray, D.P., 1994, Bedrock geologic map of Rhode Island: Kingston, R.I., Office of the Rhode Island State Geologist, Rhode Island Map Series No 1, 1 map sheet, 1:100,000. Leahy, P.P., Rosenshein, J.S., and Knopman, D.S., 1990, Implementation plan for the National Water-Quality Assessment Program: U.S. Geological Survey Open-File Report 90-174, 10 p. Lyons, J.B., Bothner, W.A., Moench, R.H., and Thompson, J.B., Jr., 1997, Bedrock geologic map of New Hampshire: Reston, Va., U.S. Geological Survey Special Map, 2 map sheets, 1:250,000. Osberg, P.H., Hussey, A.M. II, and Boone, G.M., 1985, Bedrock geologic map of Maine: Augusta, Maine, Maine Geological Survey, 1 map sheet, 1:500,000. Robinson, G.R., Jr., 1997, Portraying chemical properties of bedrock for water quality and ecosystem analysis: an approach for the New England Region: U.S. Geological Survey Open-File Report 97-154, 17 p. Robinson, G.R., Jr., Peper, J.D., Steeves, P.A., and DeSimone, L.A., 1999, Lithogeochemical character of near-surface bedrock in the Connecticut, Housatonic, and Thames River Basins: U.S. Geological Survey, Water-Resources Investigations Report 99-4000 digital. Rogers, John (compiler), 1985, Bedrock geological map of Connecticut: Connecticut Geologic and Natural History Survey, Natural Resource Atlas Map Series, 2 map sheets, 1:125,000. Zen, E-an, Goldsmith, G.R., Ratcliffe, N.L., Robinson, P., and Stanley, R.S., 1983, Bedrock geologic map of Massachusetts: U.S. Geological Survey, Monograph Series, 3 map sheets, 1:250,000. Tabled descriptions of the Major Groups and Lithogeochemical Units Item Name: Major_group Rock types can be selected on their major groupings through a redefined item called Maj_group. Maj_group is a one-column-width, interger item corresponding to the first digit in the litho_unit. When Maj_group = 1 is reselected, all of the litho_units that fall under "Carbonate-bearing metasedimentary rock groups" are selected. The breakdown is listed in the Supplemental_Information section of this document, showing both the major group and individual lithogeochemical units in that Maj_group. Below is an outline of all lithogeochemical units in each of the Major_groups. Maj_group 1: litho_unit(s) = 11u, 12u, 13u Maj_group 2: litho_unit(s) = 23u Maj_group 3: litho_unit(s) = 31u, 31c, 31s, 32u, 32c, 32s, 33u, 33c, 33s, 33cs, 34u, 34c, 34cs Maj_group 4: litho_unit(s) = 41u, 42u, 43u, 44u, 45u Maj_group 5: litho_unit(s) = 50u Maj_group 6: litho_unit(s) = 61u, 61v, 61vx, 61vz, 61x, 61xq, 61y, 61z, 62u, 62nz, 62x, 62z, Maj_group 7: litho_unit(s) = 70u, 70q, 70xq Item Name: Lithogeochemical Unit, (litho_unit) This item represents the primary lithogeochemical classification scheme used in this data set. Extended table attributes of these lithogeochemical units, including chemical character of natural waters and sensitivity to acid deposition and other habitat characteristics, are described below in the following sections: Litho_unit: 11u litho_code: 11 modifier_code: u Rock_type_description: limestone, dolomite, and carbonate-rich clastic sediments Maj_group 1: carbonate-bearing metasedimentary rocks Chemical character of natural waters: high alkalinity and high calcium and bicarbonate concentrations; neutral to high pH; may have high concentrations of sulfate and solutes complexed by bicarbonate ions. Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; flora favoring alkaline, high-calcium soils may occur; productive aquatic faunas Litho_unit: 12u litho_code: 12 modifier_code: u Rock_type_description: marble, including dolomitic marble; may include some calc-silicate rock Maj_group 1: carbonate-bearing metasedimentary rocks Chemical character of natural waters: high alkalinity and high calcium and bicarbonate concentrations; high pH; may have high concentrations of sulfate and solutes complexed by bicarbonate ion. Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; flora favoring alkaline, high-calcium soils may occur; productive aquatic faunas Litho_unit: 13u litho_code: 13 modifier_code: u Rock_type_description: calcareous clastic and metaclastic rocks containing approximately 15 to 45 percent carbonate minerals Maj_group 1: carbonate-bearing metasedimentary rocks Chemical character of natural waters: high alkalinity and high calcium and bicarbonate concentrations; neutral to high pH; may have high concentrations of sulfate and solutes complexed by bicarbonate ions. Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; flora favoring alkaline, high-calcium soils may occur; productive aquatic faunas Litho_unit: 23u litho_code: 23 modifier_code: u Rock_type_description: sandstone and interbedded sandstone and conglomerate; may contain siltstone, shale, and mudstone. Maj_group 2: primarily noncalcareous, clastic sedimentary rocks with restricted deposition in discrete fault-bounded sedimentary basins of Mississipian or younger age Chemical character of natural waters: variable Sensitivity to acid deposition and other habitat characteristics: moderately sensitivity to acid deposition Litho_unit: 31u litho_code: 31 modifier_code: u Rock_type_description: slate and graywacke Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism. Chemical character of natural waters: low to moderate solute concentrations; generally low calcium-to-sodium ratios; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous Sensitivity to acid deposition and other habitat characteristics: moderate to high sensitivity to acid deposition Litho_unit: 31c litho_code: 31 modifier_code: c Rock_type_description: slate and graywacke; noncalcareous to slightly calcareous Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism. Chemical character of natural waters: low to moderate solute concentrations; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous. Sensitivity to acid deposition and other habitat characteristics: moderate sensitivity to acid deposition Litho_unit: 31s litho_code: 31 modifier_code: s Rock_type_description: graphitic and sulfidic slate and graywacke Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: moderate solute concentrations; iron concentrations may be high in ground water where Eh and pH are low; sulfate concentrations may be high Sensitivity to acid deposition and other habitat concentrations: sensitive to acid deposition; endemic floras may occur in acidic metal-rich soils over sulfide-rich horizons Litho_unit: 32u litho_code: 32 modifier_code: u Rock_type_description: pelitic schist and phyllite; may include granofels Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; generally low calcium-to-sodium ratios; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous Sensitivity to acid deposition and other habitat characteristics: moderate to high sensitivity to acid deposition Litho_unit: 32c litho_code: 32 modifier_code: c Rock_type_description: pelitic schist and phyllite; may include granofels; noncalcareous to slightly calcareous Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; generally low calcium-to-sodium ratios; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous. Sensitivity to acid deposition and other habitat characteristics: low to moderate sensitivity to acid deposition Litho_unit: 32s litho_code: 32 modifier_code: s Rock_type_description: sulfidic schist; may include sulfidic granofels Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: moderate solute concentrations; iron concentrations may be high in ground water where Eh and pH are low; sulfate concentrations may be high Sensitivity to acid deposition and other habitat characteristics: sensitive to acid deposition; endemic floras may occur in acidic metal-rich soils over sulfide-rich horizons Litho_unit: 33u litho_code: 33 modifier_code: u Rock_type_description: mixed schist, granofels, and gneiss Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; generally low calcium-to-sodium ratios; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous Sensitivity to acid deposition and other habitat characteristics: moderate to high sensitivity to acid deposition Litho_unit: 33c litho_code: 33 modifier_code: c Rock_type_description: mixed schist, granofels, and gneiss; noncalcareous to slightly calcareous Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; variable potassium-to-sodium ratios; higher calcium concentrations when slightly calcareous Sensitivity to acid deposition and other habitat characteristics: low to moderate sensitivity to acid deposition Litho_unit: 33s litho_code: 33 modifier_code: s Rock_type_description: sulfide-bearing schistose granofels and mixed schist and gneiss (sulfidic character may be local) Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: moderate solute concentrations; iron concentrations may be high in ground water where Eh and pH are low; sulfate concentrations may be high Sensitivity to acid deposition and other habitat characteristics: moderately sensitive to acid deposition; endemic floras may occur in acidic metal-rich soils over sulfide-rich horizons Litho_unit: 33cs litho_code: 33 modifier_code: cs Rock_type_description: mixed schist, granofels, and gneiss; calcareous and sulfide-bearing (sulfidic character may be local) Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; iron concentrations may be high in ground water where Eh and pH are low; sulfate concentrations may be high Sensitivity to acid deposition and other habitat characteristics: low to moderate sensitivity to acid deposition; endemic floras may occur in acidic metal-rich soils over sulfide-rich horizons Litho_unit: 34u litho_code: 34 modifier_code: u Rock_type_description: quartzose metasandstone, quartzite, quartz granofels, and quartzose gneiss Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: generally low solute concentrations; low pH; high potassium-to-sodium ratios Sensitivity to acid deposition and other habitat characteristics: high sensitivity to acid deposition Litho_unit: 34c litho_code: 34 modifier_code: c Rock_type_description: quartzose metasandstone, quartzite, quartz granofels, and quartzose gneiss Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of waters: generally low solute concentrations; low to neutral pH; high potassium-to-sodium ratios Sensitivity to acid deposition and other habitat characteristics: moderate to high sensitivity to acid deposition Litho_unit: 34cs litho_code: 34 modifier_code: cs Rock_type_description: quartzose metasandstone, quartzite, quartz granofels, and quartzose gneiss; contains variable amounts of carbonate minerals, calc-silicate minerals, calcareous and sulfidic areas may be local. Maj_group 3: primarily noncalcareous, clastic sedimentary rocks at or above biotite-grade of regional metamorphism Chemical character of natural waters: low to moderate solute concentrations; iron concentrations may be high in ground water where Eh and pH are low; sulfate concentrations may be high Sensitivity to acid deposition and other habitat characteristics: moderate to high sensitivity to acid deposition Litho_unit: 41u litho_code: 41 modifier_code: u Rock_type_description: basalt Maj_group 4: mafic igneous rocks and their metamorphic equivalents Chemical character of natural waters: high calcium- and magnesium-to- sodium ratios; variable silica concentrations (sometimes high due to dissolution of reactive silicates); where Eh and pH are low, iron and manganese concentrations are high Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; may have endemic flora favoring alkaline, high-magnesium and low-potassium soils; productive aquatic faunas where calcium is high in surface waters Litho_unit: 42u litho_code: 42 modifier_code: u Rock_type_description: amphibolite, greenstone, greenschist-facies metavolcanics,and schistose mafic rock with minor dispersed carbonate Major group 4: mafic igneous rocks and their metamorphic equivalents Chemical character of natural waters: high calcium- and magnesium-to- sodium ratios; variable silica concentrations (sometimes high due to dissolution of reactive silicates); where Eh and pH are low, iron and manganese concentrations are high Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; may have endemic flora favoring alkaline, high-magnesium and low-potassium soils; productive aquatic faunas where calcium is high in surface waters Litho_unit: 43u litho_code: 43 modifier_code: u Rock_type_description: mafic gneiss and mafic lithologies mixed with felsic volcanics and(or) metaclastic lithologies Maj_group 4: mafic igneous rocks and their metamorphic equivalents Chemical character of natural waters: high calcium- and magnesium-to- sodium ratios; variable silica concentrations (sometimes high due to dissolution of reactive silicates); where Eh and pH are low, iron and manganese concentrations are high Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; may have endemic flora favoring alkaline, high-magnesium and low-potassium soils; productive aquatic faunas where calcium is high in surface waters Litho_unit: 44u litho_code: 44 modifier_code: u Rock_type_description: mafic plutonic rocks, including gabbro, diorite, monzodiorite, and diabase Maj_group 4: mafic igneous rocks and their metamorphic equivalents Chemical character of natural waters: high calcium- and magnesium-to- sodium ratios; variable silica concentrations (sometimes high due to dissolution of reactive silicates); where Eh and pH are low, iron and manganese concentrations are high Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; may have endemic flora favoring alkaline, high-magnesium and low-potassium soils; productive aquatic faunas where calcium is high in surface waters Litho_unit: 45u litho_code: 45 modifier_code: u Rock_type_description: mixed fine-grained felsic, mafic and(or) intermediate volcanic rocks Maj_group 4: mafic igneous rocks and their metamorphic equivalents Chemical character of natural waters: low to moderate solute concentrations; variable concentrations of silica and major ions Sensitivity to acid deposition and other habitat characteristics: variable Litho_unit: 50u litho_code: 50 modifier_code: u Rock_type_description: ultramafic rocks, including serpentinites, dunites, peridotites, and talc schists Maj_group 5: ultramafic rocks Chemical character of natural waters: high magnesium-to-calcium ratios; relatively high silica concentrations due to dissolution of reactive silicates; ground water may have low Eh values and high metal concentrations Sensitivity to acid deposition and other habitat characteristics: low sensitivity to acid deposition; frequently has endemic flora favoring high-magnesium, low-potassium, alkaline soils Litho_unit: 61u litho_code: 61 modifier_code: u Rock_type_description: granitoid plutonic rocks, including granite, quartz monzonite, granodiorite, tonalite, trondhjemite, and equivalent gneiss Maj_group 6: felsic igneous rocks and their metamorphic equivalents: may be subdivided based on age and chemistry of intrusion denoted by 'x', 'y', 'z' for the modifer code; defined in the Entity_and_ Attribute_Information section of this document. Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; relatively low pH; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61v litho_code: 61 modifier_code: v Rock_type_description: fine-grained felsic rocks of volcanic and subvolcanic origin; includes feldspathic hypabyssal dikes and flows Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61vx litho_code: 61 modifier_code: vx Rock_type_description: fine-grained felsic rocks of volcanic and subvolcanic origin; includes feldspathic hypabyssal dikes and flows Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61vz litho_code: 61 modifier_code: vz Rock_type_description: fine-grained felsic rocks of volcanic and subvolcanic origin; includes feldspathic hypabyssal dikes and flows Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61x litho_code: 61 modifier_code: x Rock_type_description: metaluminous granitoids in the Avalon terrain Maj_group 6: felsic igneous rocks and their metamorphic equivalent Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61xq litho_code: 61 modifier_code: xq Rock_type_description: generally thick unconsolidated sandy Quaternary sediments underlain by granitoids of the Avalon terrain Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61y litho_code: 61 modifier_code: y Rock_type_description: granitoid plutonic rocks, including granite, quartz monzonite, granodiorite, trondhjemite, and equivalent gneiss Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; relatively low pH; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 61z litho_code: 61 modifier_code: z Rock_type_description: granitoid plutonic rocks, including granite, quartz monzonite, quartz syenite, and equivalent gneiss Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 62u litho_code: 62 modifier_code: u Rock_type_description: quartz-poor plutonic rocks, including syenite, quartz syenite, monzonite, and anorthosite Maj_group 6: felsic igneous rocks and their metamorphic equivalents chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 62nz litho_code: 62 modifier_code: nz Rock_type_description: nepheline syenite, granitoid plutonic rocks Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; neutral to relatively high pH ground water; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 62x litho_code: 62 modifier_code: x Rock_type_description: quartz-poor plutonic rocks, including syenite, quartz syenite, monzonite, and anorthosite Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 62z litho_code: 62 modifier_code: z Rock_type_description: quartz-poor plutonic rocks, including syenite, quartz syenite, monzonite, and anorthosite Maj_group 6: felsic igneous rocks and their metamorphic equivalents Chemical character of natural waters: generally low solute concentrations; relatively high bicarbonate and silica concentrations; calcium and magnesium concentrations generally are low; fluoride, uranium, and radon concentrations may be high Sensitivity to acid deposition and other habitat characteristics: high Litho_unit: 70u litho_code: 70 modifier_code: u Rock_type_description: unconsolidated or poorly consolidated marine and(or) glacial sediments Maj_group 7: unconsolidated sediments Chemical character of natural waters: variable Sensitivity to acid deposition and other habitat characteristics: not applicable Litho_unit: 70q litho_code: 70 modifier_code: q Rock_type_description: unconsolidated or poorly consolidated marine and(or) glacial sediments: No Bedrock Defined Maj_group 7: unconsolidated sediments Chemical character of natural waters: variable Sensitivity to acid deposition and other habitat characteristics: not applicable Litho_unit: 70xq litho_code: 70 modifier_code: xq Rock_type_description: generally thick unconsolidated sandy Quaternary sediments underlain by granitoids of the Avalon terrain Maj_group 7: unconsolidated sediments Chemical character of natural waters: variable Sensitivity to acid deposition and other habitat characteristics: high Appendix A-- State (column 1), Geologic map code from source materials (column 2), lithology code (column 3), modifier code (column 4), Major group (column 5), formation name (column 6; Abbrevations used in the formation descriptions are from source materials, for Connecticut, Rodgers and other, 1985 and Hermes and others, 1994; for Massachusetts, Zen and others, 1983; for Maine, Osberg and others, 1985 and Guidotti, 1985; for New Hampshire, Lyon and others, 1997; for Rhode Island, Hermes and others, 1994. Geologic and formation names listed below are the geologic names used on the cited geologic base maps, which may not conform with the North American Stratigraphic Code, with current usage, or with current U.S. Geological Survey editorial standards. Current status of geologic name usage may be obtained from the Internet at http://ngmdb.usgs.gov/Geolex/accessed 10/19/01. CT Png 61 y 6 Narr. Pier Plut. Ste: granite subsolvus granite, lesser granodiorite and quartz monzonite CT Zeag 61 x 6 Esmond Igneous Suite: augen granite gneiss- gneiss with alkali-feldspar porphyroclasts CT Zp 34 u 3 Plainfield Formation: interlayered, thinly- bedded quartzite, mica schist, and dark- gray gneiss CT Zp+Zsh 34 u 3 Plainfield Formation plus Hope Valley Alaskite Gneiss: interlayered, thinly-bedded quartzite, mica schist, and dark-gray gneiss and light-pink to gray, medium-to coarse-grained granitic gneiss CT Zpq 34 u 3 Quartzite unit in Plainfield Formation: light-gray, glassy, generally thin bedded quartzite CT Zsag 61 x 6 Sterling Plutonic Grp: alaskite gneiss leucocratic granite gneiss CT Zsgg 61 x 6 Sterling Plutonic Grp: granite gneiss granite gneiss with biotite CT Zsh 61 x 6 Hope Valley Alaskite Gneiss: light-pink to gray, medium-to coarse-grained granitic gneiss CT Zsh+Zspp+Zsph 61 x 6 Hope Valley Alaskite Gneiss plus Porphyritic phase of Potter Hill Granite Gneiss plus Potter Hill Granite Gneiss: light-pink to gray, tan weathering, fine to medium- grained, well-foliated granitic gneiss CT Zsp 61 x 6 Ponaganset Gneiss: dark-gray to spotted, coarse-grained, well foliated gneiss CT Zss 61 x 6 Scituate Granite Gneiss: light-pink to gray, medium- to coarse-grained, lineated granitic gneiss CT Zss+Zsh 61 x 6 Scituate Granite Gneiss plus Hope Valley Alaskite Gneiss: light-pink to gray, medium- to coarse-grained, lineated granitic gneiss CT Zw 43 u 4 Waterford Group: light to dark, medium- grained gneiss CT Zwm 43 u 4 Waterford Gr: Mamacoke Formation: interlayered light- to dark grey, medium-grained gneiss CT Zwr 61 x 6 Waterford Group, Rope Ferry Gneiss MA Cbw 31 u 3 Braintree Argillite and Weymouth Fm argillite, with some rare limestone MA Cg 33 u 3 Green Lodge Fm of Rhodes and Graves (1931)-quartzite and slate MA Ch 31 u 3 Hoppin Fm--quartzite, argillite, and minor limestone MA DSdi 44 u 4 Diorite and tonalite MA DSn 61 v 6 Newbury Volcanic Complex--undivided sedimentray and volcanic rocks MA DSna 45 u 4 Newbury Volcanic Complex--porphyritic andesite, includes tuffaceous mudstone MA DSnl 45 u 4 Newbury Volcanic Complex--basalt, andesite, rhyolite, and tuff MA DSnr 61 v 6 Newbury Volcanic Complex--micrographic rhyolite MA DSnu 31 c 3 Newbury Volcanic Complex--calcareous mudstone, red mudstone, and siliceous siltstone MA DSw 31 u 3 Worcester Fm--carbonaceous slate and phyllite and minor metagraywacke MA DZl 61 vx 6 Lynn Volcanic Complex--rhyolite, agglomerate, and tuff MA Dcgr 61 y 6 Chelmsford Granite--muscovite-biotite granite MA Dcygr 61 u 6 Cherry Hill Granite--alaskite granite containing ferro-hornblende MA Dfgd 61 u 6 Fitchburg Complex--biotite granodiorite to tonalite gneiss MA Dfgds 61 u 6 Fitchburg Complex--biotite-muscovite granitic gneiss with mica schist and feldspathic granulite inclusions MA Dfgr 61 u 6 Fitchburg Complex--muscovite-biotite granite MA Dfgrg 61 u 6 Fitchburg Complex--biotite-muscovite granite to granodiorite gneiss MA Dl 32 u 3 Littleton Formation MA Dlm 12 u 1 Littleton Fm--calcitic marble MA Dmgr 61 u 6 Muscovite-biotite granite MA Dpgr 61 u 6 Peabody Granite--alkalic granite containing ferro-hornblende MA Drgr 61 u 6 Granite of Rattlesnake Hill pluton biotite-granite and fine-grained riebeckite granite MA Dwm 61 u 6 Wenham Monzonite--monzonite containing ferro-hornblende MA Jd 41 u 4 Diabase dikes and sills MA K 70 q 7 Cretaceous sediments--clay, silt, sand, and gravel, mostly non-marine and near-shore MA OZf 34 u 3 Fish Brook Gneiss--biotite-plagioclase quartz gneiss MA OZm 43 u 4 Marlboro Fm--amphibolite, biotite schist and gneiss, minor calc-silicate granofels and felsic granofels MA OZma 61 u 6 Massabesic Gneiss Complex--biotite feldspar paragneiss intruded by potassium-feldspar-rich gneiss MA OZmg 43 u 4 Marlboro Fm--feldspathic gneiss MA OZn 33 s 3 Nashoba Fm--sillimanite schist and gneiss, partly sulfidc, amphibolite, biotite gneiss, calc-silicate gneiss, and marble MA OZnb 42 u 4 Nashoba Fm: Boxford Mbr--massive amphibolite, minor biotite gneiss MA OZsh 34 cs 3 Shawsheen Gneiss--sillimanite gneiss, sulfidic at base; minor amphibolite MA Ongb 44 u 4 Nahant Gabbro and gabbro at Salem Neck labradorite-pyroxene gabbro, hornblende gabbro, and hornblende diorite MA PZb 23 u 2 Bellingham Conglomerate--red and gray metamorphosed conglomerate, sandstone, graywacke, and shale MA Pcm 32 u 3 Coal Mine Brook Fm--carbonaceous slate and garnet phyllite; lens of meta-antracite; conglomerate and arkose MA Pd 23 u 2 Dighton Conglomerate--coarse conglomerate having sandy matrix; minor sandstone MA Pgr 61 y 6 Biotite granite, with magnetite-bearing pegmatite MA Ph 33 u 3 Harvard Conglomerate--conglomerate and chloritoid-hematite phyllite MA Pp 23 u 2 Pondville Conglomerate--quartz conglomerate having abundant sandy matrix; boulder conglomerate; arkose MA Pr 23 u 2 Rhode Island Fm--sandstone, graywacke, shale, and conglomerate; minor beds of meta-antracite MA Prc 23 u 2 Rhode Island Fm--conglomerate, sandstone, and graywacke MA Pw 23 u 2 Wamsutta Fm--red to pink conglomerate, graywacke, sandstone, and shale MA Pwv 23 u 2 Wamsutta Fm--rhyolite and mafic volcanic rocks MA PzZc 31 u 3 Cambridge Argillite--gray argillite and minor quartzite; rare sandstone and conglomerate MA PzZr 31 u 3 Roxbury Conglomerate--conglomerate, sandstone, siltstone, argillite, and melaphyre MA PzZrb 31 u 3 Roxbury Conglomerate--melaphyre MA SOad 61 u 6 Ayer Granite--Devens-Long Pond facies, porphyritic gneissic biotite granite and granodiorite MA SOagr 61 u 6 Andover Granite--muscovite-biotite granite MA SObgr 61 u 6 Blue Hill Granite Porphyry-- microperthite-quartz porphyry MA SObo 32 s 3 Bolyston Schist--carbonaceous phyllite and schist, locally sulfidic; quartzite; calc- silicate beds MA SOcb 62 u 6 Cape Ann Complex: Beverly Syenite MA SOcgr 61 u 6 Cape Ann Complex--alkalic granite to quartz syenite containing ferro-hornblende MA SOcsm 61 u 6 Cape Ann Complex: Squam Granite monzodiorite MA SOngd 61 u 6 Newburyport Complex--tonalite and granodiorite MA SOqgr 61 u 6 Quincy Granite--alkalic granite containing riebeckite and aegirine MA SOvh 33 u 3 Vaughn Hills Quartzite--quartzite, phyllite, conglomerate, and chlorite schist MA SZtb 32 s 3 Tadmuck Brook Schist--andalusite phyllite and sillimanite schist, partly sulfidic; local quartzite MA Sacgr 61 u 6 Ayer Granite--Clinton facies, porphyritic biotite granite MA Sagr 61 u 6 Ayer Granite--granite to tonalite MA Sb 13 u 1 Berwick Fm--metamorphosed calcareous sandstone, siltstone, and minor muscovite schist MA Sb 33 c 3 Berwick Fm--metamorphosed calcareous sandstone, siltstone, and minor muscovite schist MA Sbs 32 s 3 Berwick Fm--mica schist MA Se 32 c 3 Eliot Fm--phyllite and calcareous phyllite MA Sgr 61 u 6 Rusty-weathering biotite granite to granodiorite MA Sngr 61 u 6 Newburyport Complex--porphyritic granite with microcline phenocrysts MA So 13 u 1 Oakdale Fm--metamorphosed pelitic and calcareous siltsone and muscovite schist MA Sp 33 cs 3 Paxton Fm--biotite granofels, calc-silicate granofels, and sulfidic schist MA Spqr 33 s 3 Paxton Fm--rusty-weathering sulfidic quartzite and sulfidic schist MA Spss 32 s 3 Paxton Fm--sulfidic mica schist MA Ssaqd 44 u 4 Straw Hollow Diorite and Assabet Quartz Diorite, undifferentiated--biotite- hornblende diorite and quartz diorite MA Ssqd 44 u 4 Sharpners Pond Diorite--biotite-hornblende tonalite and diorite MA St 34 u 3 Tower Hill Quartzite--quartzite and phyllite MA Sts 32 u 3 Tower Hill Quartzite--gray phyllite MA TRe 23 u 2 Red arkosic conglomerate, sandstone, and siltstone MA Zagr 61 x 6 Alaskite--mafic-poor gneissic granite, commonly containing muscovite MA Zb 43 u 4 Blackstone Group--undivided, quartzite, schist, phyllite, marble, and metavolcanic rocks MA Zdgr 61 x 6 Dedham Granite--granite; includes dioritic rock MA Zdi 44 u 4 Diorite--hornblende diorite metamorphosed in part to amphibolite and hornblende gneiss MA Zdigb 44 u 4 Diorite and gabbro--complex of diorite and gabbro, sub. metavolcanic rocks and intrusive granite and granodiorite MA Zdngr 61 x 6 Dedham Granite--granite to granodiorite MA Zegr 61 x 6 Esmond Granite--biotite granite MA Zfgr 61 x 6 Granite of the Fall River pluton--biotite granite, in part mafic poor MA Zgb 44 u 4 Gabbro--hornblende gabbro and hornblende- pyroxene gabbro metamorphosed in part to hornblende gneiss and amphibolite MA Zgg 61 x 6 Granite, gneiss, and schist, undivided plutonic and metamorphic rocks MA Zgg 61 xq 6 Granite, gneiss, and schist, undivided plutonic and metamorphic rocks MA Zgg 70 xq 7 Granite, gneiss, and schist, undivided plutonic and metamorphic rocks MA Zgmgd 61 x 6 Grant Mills Granodiorite--porphyritic granodiorite MA Zgn 33 u 3 Biotite gneiss near New Bedford feldspathic gneiss MA Zgr 61 x 6 Biotite granite MA Zgs 33 u 3 Gneiss and schist near New Bedford hornblende and biotite schist and gneiss, amphibolite MA Zhg 61 x 6 Hope Valley Alaskite Gneiss--mafic-poor gneissic granite, locally containing muscovite MA Zm 61 vx 6 Mattapan Volcanic Complex--rhyolite, melaphyre, agglomerate, and tuff MA Zmgd 61 x 6 Milford Granite--seriate to subporphyritic granite to granodiorite, locally gneissic MA Zmgr 61 x 6 Milford Granite--biotite granite, locally gneissic MA Zp 34 u 3 Plainfield Fm--quartzite, pelitic schist, minor calc-silicate rock and amphibolite MA Zpg 61 x 6 Ponaganset Gneiss--gneissic biotite granite containing megacrysts of microcline MA Zpgr 61 x 6 Porphyritic granite--seriate to porphyritic biotite granite with epidote and sphene and mafic inclusions MA Zrdi 44 u 4 Diorite at Rowley--hornblende diorite MA Zsg 61 x 6 Scituate Granite Gneiss--gneissic granite containing biotite MA Zssy 62 x 6 Sharon Syenite--syenite containing microperthite, oligoclase, and clinopyroxene, mixed with ferro-gabbro MA Ztgd 61 x 6 Topsfield Granodiorite--porphyritic granodiorite MA Zv 45 u 4 Metamorphosed mafic to felsic flow, and volcaniclastic and hypabyssal intrusive rocks MA Zvf 61 vx 6 Metamorphosed felsic metavolcanic rocks MA Zw 33 u 3 Westboro Fm--quartzite, schist, calc- silicate quartzite, and amphibolite MA Zwgr 61 x 6 Westwood Granite MA grg 61 u 6 Biotite granitic gneiss MA igd 61 u 6 Granodiorite of the Indian Head pluton biotite granodiorite and hornblende- biotite tonalite MA mgr 61 u 6 Muscovite granite MA u 50 u 5 Serpentinite ME C1 61 u 6 Biotite granite (GS) ME C1(m) 61 u 6 Muscovite-biotite granite (E,AA,AB) ME C1b(m) 61 y 6 Biotite-muscovite granite (AB,AC) ME C1b(m,s) 61 y 6 Muscovite-biotite granite with abundant metasedimentary inclusions ME C4a 61 z 6 Alkali-feldspar quartz syenite (AB) ME C7 62 z 6 Syenite (AB) ME C9 44 u 4 Gabbro, diorite, or ultramafic rocks (GS,E,AB) ME C-6 44 u 4 Quartz diorite (GS) ME C-9 44 u 4 Garbbo, diorite, or ultramafic rocks (W,GS) ME C-9c 50 u 5 Ultramafic rocks(GS) ME C-h 33 u 3 Hurricane Mountain Formation--W,GS (melange) ME C-ha 42 u 4 Hurricane Mtn Fm: Amphibolite and greenschist (W) (basaltic volcanic rocks) ME C-hmg 44 u 4 Hurricane Mtn Fm: Metagabbro 9a,b (GS) ME C-hpx 44 u 4 Hurricane Mtn Fm: Metapyroxenit 9c (GS) ME C-hq 34 u 3 Hurricane Mtn Fm: Black and gray metaquartzite (GS) (quartz sandstone) ME C-hqw 34 u 3 Hurricane Mtn Fm: Metaquartzwacke (W) (feldspathic sandstone) ME C-hr 61 v 6 Hurricane Mtn Fm: Metafelsite (W) (rhyolitic volanic rocks) ME C-j 45 u 4 Jim Pond Formation--GS (mafic to felsic volcanic rocks) ME C-jf 33 u 3 Jim Pond Fm: Quartzwacke and pelite (W,GS) (lithic sandstone) ME C-jg 41 u 4 Jim Pond Fm: Mafic volcanic rocks (W,GS) (basaltic volcanic rocks) ME C-jk 61 v 6 Jim Pond Fm: Felsic volcanic rocks (GS) (rhyolitic volanic rocks) ME C-jp 33 u 3 Jim Pond Fm: Sandstone, mudstone, and pelite (W,GS) (interbed. pelite and ss) ME C-jq 31 u 3 Jim Pond Fm: Graywacke (GS) (feldspathic sandstone) ME C-uvm 41 u 4 Unnamed mafic volcanic rocks (GS) (basaltic volcanic rocks) ME D1 61 u 6 Granite (U,W,GS,E,AA,AB,AC) ME D1(m) 61 u 6 Muscovite-biotite granite (W,GS,E,AA,AB,AC) ME D1(x) 61 u 6 Porphyritic granite (U) ME D1,2(h) 61 u 6 Biotite-hornblende granite and biotite-hornblende granodiorite (GS) ME D1-6 44 u 4 Granite to quartz diorite--E ME D10(h) 62 nz 6 Foid-bearing biotite-hornblende syenite (AB) ME D1b 61 u 6 Granite (W,GS,E,AA,AB) ME D1b(m) 61 u 6 Muscovite-biotite granite (GS,AA,AB,AC) ME D1b(m),3 61 u 6 Muscovite-biotite granite and tonalite ME D2 61 u 6 Granodiorite (GS,E,AB,AC) ME D2(h) 61 u 6 Hornblende-biotite granodiorite (W,GS) ME D2(m) 61 u 6 Muscovite-biotite granodiorite (GS,E,AA,AB) ME D2-4b 61 u 6 Granodiorite to quartz diorite--E ME D3 61 u 6 Tonalite--AB,AC ME D4c(m) 61 u 6 Muscovite-biotite quartz monzonite (AB) ME D5,6(p) 44 u 4 Quartz monzodiorite and pyroxene-biotite quartz diorite (AB) ME D9 44 u 4 Gabbro, diorite, and ultramafic rocks (GS,E,AA,AB,AC) ME D9a 44 u 4 Diorite (GS) ME D9b 44 u 4 Gabbro (GS,E) ME D9b-c 50 u 5 Gabbro to ultramafic rocks--GS,E,AB ME DC-us 33 u 3 Unnamed sedimentary rocks (GS) (interbed. pelite and ss) ME DOb 33 c 3 Bucksport Formation (U,W,GS,E,AA,AB,AC) (calc. ss; interbed. ss & imp. ls) ME DOup 32 u 3 Unnamed pelite (GS) (pelite) ME DSm 33 c 3 Madrid Formation--E,AA,AB,AC (calc. ss; interbed. ss and imp. ls) ME DSm 13 u 1 Madrid Formation--W,GS (calc. ss; interbed. ss and imp. ls) ME DSmig 61 u 6 Undiff. sed. rks ext. migmatization (interbed. pelite and ss) ME DSra 33 u 3 Rindgemere Formation: Upper member (AA,AB) (interbed. pelite and ss) ME DSrb 33 c 3 Rindgemere Formation: Lower member E,AA,AB, (interbed. pelite and ls and(or) dols) ME DSrbl 12 u 1 Rindgemere Fm: Lower member: limestone--AB (limestone and(or) dolostone) ME DSrbr 32 s 3 Rindgemere Fm: Lower member: sulfidic pelite (AA,AB) (sulfidic/carbonaceous pelite) ME DSt 32 s 3 Towow Formation (AA,AB) (sulfidic/carbonaceous pelite) ME DStc 34 u 3 Towow Formation: Conglomerate member (AA) (conglomerate) ME DSuss 33 u 3 Unnamed conglomeratic sandstone (GS) (conglomerate) ME DSuv 45 u 4 Unnamed volcanic rocks--GS (mafic to felsic volcanic rocks) ME DZg 32 u 3 Gonic Formation (E) (pelite) ME Db 13 u 1 Beck Pond Limestone (GS) (interbed. pelite, ss, and ls and(or) dols) ME Dc 32 u 3 Carrabassett Formation (GS,E,AA) (pelite) ME Dcm 32 u 3 Carrabassett Fm: Massive pelite member (W,GS,E) (pelite) ME Dcq 34 u 3 Carrabassett Fm: Quartzite member (GS,E) (quartz sandstone) ME Dcs 33 u 3 Carrabassett Fm: Thinly layered member (GS,E) (interbed. pelite and ss) ME Dh 13 u 1 Hildreths Formation (GS,E,AA,AB,AC) (interbed. pelite, ss, and ls and/or dols) ME Dhb 34 u 3 Hobbstown Formation (GS) (lithic sandstone and congl) ME Dhm 61 v 6 Heald Mountain Rhyolite (GS) (rhyolitic volanic rocks ME Dhmd 61 v 6 Heald Mtn Rhyolite: Dark tuff member (GS) (rhyolitic volanic rocks) ME Dim 32 u 3 Ironbound Mountain Formation (W,GS) (pelite) ME Dl 33 u 3 Littleton Formation (AB,AC) (interbed. pelite and ss) ME Dpk 12 u 1 Parker Bog Formation--GS (limestone and(or) dolostone) ME Ds 33 u 3 Seboomook Formation (W,GS,E,AA,AB,AC) (interbed. pelite and ss) ME Dsc 42 u 4 Seboomook Fm: Camera Hill Greenstone (GS) (basaltic volcanic rocks) ME Dsd 33 u 3 Seboomook Fm: Day Mountain Member (GS,E,AA,AB,AC) (interbed. pelite and ss) ME Dsdc 34 u 3 Seboomook Fm: Day Mountain Member, Conglomerate (GS) (conglomerate) ME Dsdl 12 u 1 Seboomook Fm: Day Mountain Member, Limestone--AA,E,GS (limestone and(or) dolostone) ME Dsm 13 u 1 Seboomook Fm: Mount Blue Member (GS,E,AA,AB) (interbed. pelite and ss) ME Dsm 33 u 3 Seboomook Fm: Mount Blue Member (GS,E,AA,AB) (interbed. pelite and ss) ME Dst 32 s 3 Seboomook Fm: Temple Stream Member (GS,E,AA,AB,AC) (sulfidic/carbonaceous pelite) ME Dt 33 u 3 Tarratine Formation (W,GS) (feldspathic sandstone) ME Dtm 34 u 3 Tarratine Fm: Misery Quartzite (W) (quartz sandstone) ME Dtmc 11 u 1 Tarratine Fm: McKenny Pond Limestone (GS) (interbed. pelite, ss, and ls and(or) dols) ME Dto 33 u 3 Tomhegan Formation (GS) (feldspathic sandstone) ME Dtokc 61 v 6 Tomhegan Fm: Kineo Rhyolite Member: tuffs and volcaniclastic rocks (W,GS) (rhyolitic volc. rks) ME Dtokg 61 v 6 Tomhegan Fm: Kineo Rhyolite Member: garnet rhyolite (W) (rhyolitic volanic rocks) ME Dtokm 61 v 6 Tomhegan Fm: Kineo Rhyolite Member: Massive felsite (W,GS) (rhyolitic volanic rocks) ME Durg 61 v 6 Unnamed garnet rhyolite (W,GS) (rhyolitic volanic rocks) ME Duvm 42 u 4 Unnamed mafic volcanic rocks (GS) (basaltic volcanic rocks) ME Dw 34 u 3 Whiskey Quartzite (GS) (quartz sandstone) ME J1 61 z 6 Granite (AB) ME K1a 61 z 6 Alkali-feldspar granite (GS) ME K1b 61 z 6 Granite (GS) ME K4a 61 z 6 Alkali-feldspar quartz syenite (GS) ME K5 44 u 4 Quartz monzonite (AB) ME K6,9 44 u 4 Quartz diorite and gabbro, diorite, and ultramafic rocks (GS) ME K7a 62 z 6 Alkali-feldspar syenite (GS,AB) ME K8 44 u 4 Monzodiorite (AB) ME K9 44 u 4 Gabbro, diorite, and ultramafic rocks (GS,AB) ME Kv 61 vz 6 Mafic to felsic volcanic rocks (AB) (mafic to felsic volcanic rocks) ME Mz1(h) 61 z 6 Hornblende-biotite granite (AB) ME Mz10 62 nz 6 Foid-bearing syenite (AC) ME Mz7 62 z 6 Syenite (AC) ME Mz7a 62 z 6 Alkali-feldspar syenite (AB) ME Mz9 44 u 4 Gabbro, diorite, and ultramafic rocks (AB) ME Mzv 61 vz 6 Mafic to felsic volcanic rocks (AB) (mafic to felsic volcanic rocks) ME O1 61 u 6 Granite (GS) ME O1b 61 u 6 Alkali-feldspar granite (GS,E,AA,AB) ME O1b,2 61 u 6 Alkali-feldspar granite and granodiorite (AB) ME O2 61 u 6 Granodiorite (W,GS) ME O4c(h) 61 u 6 Hornblende-biotite quartz monzonite (GS) ME O9 44 u 4 Gabbro, diorite, and ultramafic rocks (W,GS) ME OC-d 33 u 3 Dead River Formation (E,AB) (interbed. pelite and ss) ME OC-dp 33 u 3 Dead River Fm: Lower member (W,GS,E,AA,AB)(interbed. pelite and ss) ME OC-dq 33 u 3 Dead River Fm: Upper member (W,GS,E)(feldspathic sandstone) ME OC-z 32 u 3 Aziscohos Formation--GS,E,AA,AB,AC (pelite) ME Ozc 43 u 4 Cushing Formation (GS,E,AA,AB,AC) (mafic to felsic volcanic rocks) ME OZce 33 u 3 Cape Elizabeth Formation (GS,E,AA,AB,AC) (interbed. pelite and ss) ME OZceq 34 u 3 Cape Elizabeth Fm: Quartzite member (AB,AC)(quartz sandstone) ME OZcg 42 u 4 Cushing Fm: Mafic volcanic member (E,AB,AC)(basaltic volcanic rocks) ME OZcl 12 u 1 Cushing Fm: Limestone member (AB,AC) (limestone and(or) dolostone) ME OZcq 34 u 3 Cushing Fm: Quartzite member (E,AA,AB) (quartz sandstone) ME OZcr 32 s 3 Cushing Fm: Sulfidic pelite member (E,AA,AB,AC) (sulfidic/carbonaceous pelite) ME OZj 32 s 3 Jewell Formation (GS,E,AA) (sulfidic/carbonaceous pelite) ME OZm 31 c 3 Macworth Formation (GS,E,AA,AB) (calcareous pelite) ME OZs 45 u 4 Spring Point Formation--E,AA,AB,AC (mafic to felsic volcanic rocks) ME OZs 44 u 4 Spring Point Formation--GS (mafic to felsic volcanic rocks) ME OZsc 33 u 3 Scarboro and Diamond Island Formations (E,AA,AB,AC) (sulfidic/carbonaceous pelite) ME OZsk 11 u 1 Spurwink Limestone (GS,E,AA) (limestone and/or dolostone) ME Oam 42 u 4 Ammonoosuc Volcanics (AB) (mafic to felsic volcanic rocks) ME Ok 61 v 6 Kennebec Formation (W) (rhyolitic volcanic rocks) ME Okmg 41 u 4 Kamankeag Fm: Basalt and graywacke member (GS,E,AA) (feldspathic sandstone) ME Okms 32 u 3 Kamandeag Fm: Pelite member (GS,E,AA) (sulfidic/carbonaceous pelite) ME Olm 42 u 4 Lobster Mountain Vol. Complex--GS (mafic to felsic volcanic rocks) ME Olm 41 u 4 Lobster Mountain Vol. Complex--W (mafic to felsic volcanic rocks) ME Olma 41 u 4 Lobster Mtn Vol: Andesite member (W) (andesitic volcanic rocks) ME Olmb 41 u 4 Lobster Mtn Vol: Basalt member (W) (basaltic volcanic rocks) ME Oq 33 u 3 Quimby Formation (GS,E,AA,AB) (interbed. pelite and ss) ME Oqg 31 u 3 Quimby Fm: Graywacke member (GS) (lithic sandstone) ME Oqs 31 u 3 Qiumby Fm: Pelite member (GS) (interbed. pelite and ss) ME Oqv 61 v 6 Quimby Fm: Rhyolitic volcanic member (GS) (rhyolitic volanic rocks) ME Ouvm 42 u 4 Unnamed mafic volcanic rocks (GS,AB) (basaltic volcanic rocks) ME Ouvs 45 u 4 Unnamed volcanic and sedimentary rocks W,GS (mafic to felsic volcanic rocks) ME S1 61 u 6 Granite (GS) ME S9 44 u 4 Gabbro, diorite, and ultramafic rocks (GS) ME SOf 33 u 3 Frontenac Formation (W,GS) (interbed. pelite and ss) ME SOfc 41 u 4 Frontenac Fm: Canada Falls Volcanic Mbr (W,GS) (basaltic volcanic rocks) ME SOup 32 u 3 Unnamed pelite (W,GS,E,AA,AB) (pelite) ME SOur 32 s 3 Unnamed sulfidic pelite (E,AA,AB) (sulfidic/carbonaceous pelite) ME SOus 33 u 3 Unnamed sedimentary rocks (GS) (interbed. pelite and ss) ME SOv 33 c 3 Vassalboro Formation--E,AA,AB,AC (calc. ss; interbed. ss & imp. ls) ME SOv 13 u 1 Vassalboro Formation--GS (calc. ss; interbed. ss & imp. ls) ME SOvv 61 v 6 Vassalboro Fm: Volcanic member (GS,E) (rhyolitic volanic rocks) ME SZb 33 c 3 Berwick Formation (GS,E) (calcareous feldspathic sandstone) ME SZe 32 c 3 Eliot Formation (GS) (calcareous pelite) ME SZk 33 c 3 Kittery Formation (GS) (calcareous feldspathic sandstone) ME Sc 32 u 3 Capens Formation (W,GS) (pelite) ME Sg 33 c 3 Greenvale Cove Formation (GS,E,AA,AB) (calcareous lithic sandstone) ME Shm 13 u 1 Hardwood Mountain Formation--GS (interbed. pelite, ss, and ls and(or) dols) ME Sp 33 u 3 Perry Mountain Formation (GS) (interbed. pelite and ss) ME Sr 33 u 3 Rangeley Formation (GS,AB,AC) (interbed. pelite and ss) ME Sra 33 u 3 Rangely Fm: 'A' member (GS,E,AA,AB) (interbed. pelite and ss) ME Srac 34 u 3 Rangely Fm: 'A' member, Lithic sandstone (E,AA,AB) (lithic sandstone and congl) ME Srb 33 u 3 Rangely Fm: 'B' member (E,AA,AB) (interbed. pelite and ss) ME Src 33 u 3 Rangely Fm: 'C' member (GS,E,AA,AB) (interbed. pelite and ss) ME Srp 34 c 3 Ripogenus Formation (W,GS) (calcareous quartz sandstone) ME Ss 33 c 3 Sangerville Formation--E,AA,AB,AC (interbed pelite and ls and(or) dols) ME Ss 13 u 1 Sangerville Formation--GS (interbed. pelite and ls and(or) dols) ME Ssa 33 u 3 Sangerville Fm: Anasagunticook Member (GS,E,AA,AB,AC) (interbed. pelite and ss) ME Ssal 11 u 1 Sangerville Fm: Anas. Mbr: Limestone (AB,AC) (limestone and(or) dolostone) ME Ssar 32 s 3 Sangerville Fm: Anas. Mbr: Sulfidic pelite (AB,AC) (sulfidic/carbonaceous pelite) ME Ssc 34 u 3 Sangerville Fm: Conglomerate member (GS) (conglomerate) ME Ssf 32 s 3 Smalls Falls Formation (GS,E,AA,AB,AC) (sulfidic/carbonaceous pelite) ME Ssl 11 u 1 Sangerville Fm: Limestone member (GS,E,AA,AB,AC) (limestone and(or) dolostone) ME Sspm 11 u 1 Sangerville Fm: Patch Mountain Member (GS,E,AA,AB,AC) (limestone and(or) dolostone) ME Ssr 32 s 3 Sangerville Fm: Sulfidic pelite member (AB,AC) (sulfidic/carbonaceous pelite) ME Stf 33 c 3 The Forks Formation--E (argill. limestone and(or) dolostone) ME Stf 13 u 1 The Forks Formation--GS (argill. limestone and(or) dolostone) ME Suc 34 u 3 Unnamed conglomerate (W,GS) (conglomerate) ME Sul 11 u 1 Unnamed limestone (W,GS) (limestone and(or) dolostone) ME Sur 32 s 3 Unnamed sulfidic pelite (GS,E,AA,AB,AC) (sulfidic/carbonaceous pelite) ME Suvm 41 u 4 Unnamed mafic volcanic rocks--W,GS,E (basaltic volcanic rocks) ME Sw 33 u 3 Waterville Formation (GS,E,AA,AB,AC) (interbed. pelite and ss) ME Swl 12 u 1 Waterville Fm: Limestone member (GS,E,AA,AB,AC) (limestone and(or) dolostone) ME Zr 33 u 3 Rye Formation (GS) (interbed. pelite and ss) ME pC-c 61 u 6 Gneisses: Chain Lakes Massif (GS) (basement) NH -Ch 33 u 3 Hurricane Mtn Fm--rusty-weathered, silceous slate or schist; melange of metased., felsic and mafic metavolcanic, and ultramafic rks NH -Cjb 42 u 4 Jim Pond Fm--pillow metabasalt mbr NH D1b 61 u 6 NH PS: Pink equigranular biotite granite NH D1m 61 y 6 NH PS: Two-mica granite of northern and southeastern NH NH D3Ab 61 u 6 NH PS: Biotite tonalite NH D3Bb 61 u 6 NH PS: Biotite trondhjemite in Rumney Quadrangle NH D6 44 u 4 NH PS: Biotite quartz diorite in northeastern NH NH DS9 44 u 4 NH PS: Metamorphosed gabbro, diorite, and intrusive basalt dikes NH DSlr 61 u 6 Migmatitic rocks--formations unidentifiable owing to obliteration of orig. sed. or volc. characteristics by anatexis or intrusions NH Db2b 61 u 6 NH PS: Bethlehem Granodiorite biotite, muscovite granodiorite and assoc. tonalite and granite NH Dc1m 61 y 6 NH PS: Concord Granite--two-mica granite, locally grading to tonalite NH Dc3Am 61 y 6 NH PS: Two-mica tonalite NH De9 44 u 4 NH PS: Exeter Diorite--with assoc. pyroxene and pyx-hornblende diorite and gabbro, minor grdi-gr NH Di 31 u 3 Ironbound Mtn Fm, undivided, interbedded phyllite and feldspathic metasandstone NH Die 31 s 3 Ironbound Mtn Fm: Euxinic metashale member NH Dif 61 v 6 Ironbound Mtn Fm: Felsic volcanic member NH Dir 61 v 6 Ironbound Mtn Fm: Metarhyolite and microgranite intrusions NH Dk2x 61 u 6 NH PS: Kinsman Granodiorite--granite, granodiorite, tonalite and minor qtz diorite NH Dl 32 u 3 Littleton Fm, undivided: metapelite and metawacke and sub. metavolcanic rocks NH Dlc 33 c 3 Littleton Fm: Calc-silicate rock (?Hildreths Fm, ME) NH Dlcs 34 u 3 Littleton Fm: Metaconglomerate and quartzite NH Dll 32 u 3 Littleton Fm: Lower unnamed mbr-- aluminous, somewhat rusty (?Carrabassett Fm, ME) NH Dlu 31 u 3 Littleton Fm: Upper unnamed mbr-- metaturbidite (lithologic = Seboomoock Fm, ME) NH Dlvb 42 u 4 Littleton Fm: Metabasaltic greenstone or amphibolite NH Ds1-6 61 u 6 NH PS: Spaulding Tonalite--biotite quartz diorite, tonalite, granodiorite, and granite NH Ds6-9B 44 u 4 NH PS: Hypersthene-biotite quartz diorite and hornblende or actinolite diorite or gabbro NH Dw3A 61 u 6 NH PS: Winnipesaukee Tonalite--tonalite and minor quartz diorite, granodiorite and granite NH J1-4l 61 z 6 WM PVS: Leuocratic granite to quartz syenite NH J1O 62 nz 6 WM PVS: Nepheline-sodalite-hastingsite syenite NH J1h 61 z 6 WM PVS: Hastingsite granite NH J1hx 61 z 6 WM PVS: Granite porphyry NH J1r 61 z 6 WM PVS: Mesoperthitic granite NH J1x 61 z 6 WM PVS: Porphyritic granite NH J4h 61 z 6 WM PVS: Hornblende or alkalic amphibole quartz syenite--quartz monzodiorite to diorite NH J4hx 61 z 6 WM PVS: Porphyritic hornblende or alkalic amphibole quartz syenite NH J4x 62 z 6 WM PVS: Quartz syenite NH J5 44 u 4 WM PVS: Hornblende-biotite quartz monzodiorite NH J7h 62 z 6 WM PVS: Hornblende (or alkalic amphibole) syenite NH J7x 61 z 6 WM PVS: Porphyritic syenite NH J8 44 u 4 WM PVS: Augite monzodiorite NH J9A 44 u 4 WM PVS: Diorite NH J9B 44 u 4 WM PVS: Gabbro NH Jc1b 61 z 6 WM PVS: Conway Granite--mesoperthic biotite granite NH Jmv 61 vz 6 WM PVS: Moat Volcanics--ignimbritic tuffs, flows, and breccia, with por. rhyolite NH Jo1b 61 z 6 WM PVS: Mount Osceola Granite: biotite mesoperthitic granite NH Jo1h 61 z 6 WM PVS: Mount Osceola Granite: granite with hornblende, locally hastingsite, ferro NH K1a 61 vz 6 WM PVS: Rhyolite and fine-grained granite NH K1bx 61 z 6 WM PVS: Porphyritic biotite granite NH K1r 61 z 6 WM PVS: Mesoperthitic granite, with riebeckite and(or) hastingsite NH K2 61 z 6 WM PVS: Biotite-hornblende granodiorite NH K4x 61 z 6 WM PVS: Large mesoperthitic phenocrysts in quartz syenite of "Albany type" NH K7C 61 z 6 WM PVS: Augite-hornblende-biotite monzonite NH K9A 44 u 4 WM PVS: Hornblende diorite NH K9AB 44 u 4 WM PVS: Augite-hornblende diorite and gabbro NH K9B 44 u 4 WM PVS: Augite-hornblende-biotite gabbro NH Kc1b 61 z 6 WM PVS: Mesoperthic biotite granite NH Kv 44 u 4 WM PVS: Basalt, minor rhyolite ignimbrite and andesitic tuff NH MD1m 61 y 6 WM PVS: Two-mica granite NH MD3B 61 y 6 WM PVS: Trondhjemite and abundant pegmatite NH O-Cd 33 u 3 Dead River Fm, undivided--metapelite and quartzite NH O-Czl 32 u 3 Aziscohos Fm: Lower unnamed mbr--rusty metapelite, feldpathic metatuff, and vein qtz NH O-Czu 32 u 3 Aziscohos Fm: Upper unnamed mbr--metapelite and vein quartz NH OZrb 61 u 6 Rye Complex: Breakfast Hill Granite--mylon. qtz-feldspar granitic gneiss and pegmatite NH OZrz 33 u 3 Rye Complex--migmatite of two-mica granite and pegmatite; minor hornblende diorite, intruding metapelites, and metavolcanic rocks NH Oal 42 u 4 Ammonoosuc Volcanics: metavolcanic and metased. rocks of lower part, undivided NH Oalb 42 u 4 Ammonoosuc Volcanics: metabasalt NH Oalg 32 u 3 Ammonoosuc Volcanics: Volcaniclastic metagraywackes NH Oali 32 u 3 Ammonoosuc Volcanics: White quartz-kyanite rock and silicate iron-formation NH Oalx 45 u 4 Ammonoosuc Volcanics: Bimodal volcanic rocks NH Oc1b 61 u 6 CW Intrusions: Biotite granite (Cambridge Black pluton) NH Oc3Ah 61 u 6 CW Intrusions: Hornblende-biotite tonalite NH Oc3Ax 61 u 6 CW Intrusions: Porphyritic phase of hornblende-biotite tonalite NH Oc9B 44 u 4 CW Intrusions: Gabbro and diabase NH Oo1b 61 u 6 Oliv PS: Biotite granite NH Oo1bx 61 u 6 Oliv PS: Porphyritic (alkalic feldspar) biotite granite NH Oo2-3A 61 u 6 Oliv PS: Granodiorite to tonalite NH Oo2b 61 u 6 Oliv PS: Biotite granodiorite NH Oo2bx 61 u 6 Oliv PS: Porphyritic biotite granodiorite in no. Jefferson dome NH Oo3B-6 61 u 6 Oliv PS: Trondhjemite and quartz diorite in no. Jefferson dome NH P1m 61 y 6 WM PVS: Gray biotite granite NH PM1m 61 y 6 WM PVS: Two-mica granite of the Sebago batholith and Effingham pluton NH S1b 61 u 6 NH PS: Biotite granite stock and dikes NH SOb 33 c 3 Berwick Fm--Biotite-quartz-feldspar granofels or schist and interbeds of calc-silicate granofels and minor metapelites NH SObc 13 u 1 Berwick Fm: Unnamed mbr--more calc-silicate (15%) than the rest of the fm (5%) NH SObc 33 c 3 Berwick Fm: Unnamed mbr--more calc-silicate (15%) than the rest of the fm (5%) NH SObg 32 u 3 Berwick Fm: Gove Mbr--white muscovite shist NH SOe 32 c 3 Eliot Fm--Phyllite, calcareous quartzite, quartz-mica schist, and calc-silicate NH SOec 32 s 3 Eliot Fm: Calef Mbr--black phyllite NH SOk 33 c 3 Kittery Fm--calcareous metass and phyllite NH Sa2x 61 u 6 NH PS: Ayer Granodiorite--gneissic granite to tonalite, locally porphyritic and muscovitic NH Sc 34 u 3 Clough Quartzite--orthoquartzite, qtz metacgl, muscovite schist, minor polymict metacgl NH Sf 13 u 1 Fitch Fm--metamorphosed limestone, calcareous sandstone, siltsone, and pelitic schist NH Sfr 31 u 3 Frontenac Fm, undivided, interbed feldpathic wackes, slates, and minor calc. lenses NH Sfrb 42 u 4 Frontenac Fm: Metabasalt interbeds NH Sfrx 45 u 4 Frontenac Fm: Proximal bimodal volcanic facies NH Sm 33 c 3 Madrid Fm--biotite-feldspar granofels, calc-silicate, and pelitic-sulfidic schist NH Smsf 32 s 3 Madrid and Smalls Falls Fms, undivided NH Sn1x 61 u 6 NH PS: Newburyport Complex--porphyritic granite NH Sn2-3A 61 u 6 NH PS: Newburyport Complex--tonalite and granodiorite NH Sp 33 u 3 Perry Mtn Fm, undivided--interbed. quartzites, nongraphitic metapelite, metaturbitite NH Spr 32 s 3 Perry Mtn and Rangely Fms, undivided NH Spvs 33 u 3 Perry Mtn Fm: Sedimentary and sub. distal felsic and mafic volcanics NH Sr 33 s 3 Rangely Fm, undivided NH Src 33 u 3 Rangely Fm: Member C--quartz pebble cgl overlain by rusty metapelite and feld. qtzite NH Srl 33 u 3 Rangely Fm: Lower part--metapelite, turbidite lentils, thin qtz clg NH Srlp 33 c 3 Rangely Fm: Calc-silicate NH Sru 33 s 3 Rangely Fm: Upper part--rusty weathering, pelitic schist, meta ss; calc-silicate pods NH Srup 33 c 3 Rangely Fm: Calc-silicate and biotite granofels NH Srvf 61 v 6 Rangely Fm: Felsic metavolcanic rocks NH Ssf 32 s 3 Smalls Falls Fm, undivided--v. rusty weathering, sulfidic-graphitic shist and pyrrhotitic calc-silicate granofels NH Ssfb 42 u 4 Smalls Falls Fm: Metabasalt member NH Ssfc 34 u 3 Smalls Falls Fm: Metaconglomerate member NH Ssff 31 u 3 Smalls Falls Fm: Felsic metavolcanic member NH Ssfx 31 u 3 Smalls Falls Fm: Mixed metavolcanic rocks and metavolcanic sediments NH Zmz 61 u 6 Massabesic Gneiss Complex--migmatite of biotite granite intruding gneissic and granulose metasedimentary and metavolcanic rocks RI Ch 31 u 3 Hoppin Fm--quartz arenite, argillite, and minor limestone RI Cpc + Occj 13 u 1 Pirate Cove Formation (Cpc) and Jamestown Formation (OCcj): Green to black phyllit interstratified with buff to pink siltstone and pink to buff white, thinly laminated marble units (Cpc) at base. RI DZc 50 u 5 cumberlandite--porphyritic melatroctolite with magnetite and ilmenite RI DZgd 44 u 4 gabbro/diorite--quartz diorite and gabbro RI Dsa 61 u 6 Scituate Igneous Suite:alkali-feldspar granite--hypersolvus alkali-felspar granite with mafic mineral clots RI Dsd 44 u 4 Scituate Igneous Suite: diorite/gabbro-- quartz diorite, diorite, and gabbro RI Dsfg 61 u 6 Scituate Igneous Suite: fine-grained granite RI Dsg 61 u 6 Scituate Igneous Suite: granite--subsolvus granite with mafic-mineral clots RI Dsgd 61 u 6 Scituate Igneous Suite: granodiorite RI Dsm 61 u 6 Scituate Igneous Suite: monzonite/ monzodiorite--quartz monzonite, monzonite, and monzodiorite RI Dsr 61 v 6 Scituate Igneous Suite: rhyolite RI Dsv 61 v 6 Scituate Igneous Suite: volcaniclastic rock--tuff, ignimbrite, ash-flow tuff, and epiclastic rock (sandstone, breccia, conglomerate) with abundant volcanic detritus RI Jm 50 u 5 monchiquite--mafic to ultramafic lamprophyre dike rock RI Kr 70 u 7 Raritan Fm--poorly consolidated clay and white sand RI MDca 61 y 6 alkali-feldspar granite of Cumberland-- hypersolvus alkali-feldspar granite RI 70 q 7 No Bedrock Defined RI OCcdi 32 u 3 Conanicut Grp: Dutch Island Harbor Fm--dark gray phyllite RI OCcep 33 u 3 Conanicut Grp: East Passage Fm--phyllite, sandstone, siltstone, and volcaniclastic rock RI OCcj 33 u 3 Conanicut Grp: Jamestown Fm--green and gray phyllite interstratified with siltstone RI OCcj+OCcfb 33 u 3 Conanicut Grp: Jamestown Fm plus Fort Burnside Fm -green and gray phyllite interstratified with siltstone RI OCcu 33 u 3 Conanicut Grp: undifferentiated rock RI PZmc 23 u 2 metaclastic rock, undivided--polymict conglomerate, sandstone, and shale RI Pnbpo 23 u 2 Narragansett Bay Grp: Pondville Conglomerate --conglomerate interbedded with sandstone, litharenite, slate, and siltstone RI Pnbpu 23 u 2 Narragansett Bay Grp: Purgatory Conglomerate RI Pnbr 23 u 2 Narragansett Bay Grp: Rhode Island Fm-- sandstone, shale, and conglomerate, with minor coal layers RI Pnbs 23 u 2 Narragansett Bay Grp: Sachuest Arkose-- quartz granule conglomerate, sandstone, and phyllite RI Pnbw 23 u 2 Narragansett Bay Grp: Wamsutta Fm--red sandstone, shale, and conglomerate with locally abundant volcanic detritus as clasts and matrix RI Pnfg 61 y 6 Narr. Pier Plut. Ste: fine-grained granite RI Png 61 y 6 Narr. Pier Plut. Ste: granite--subsolvus granite, lesser granodiorite and quartz monzonite RI Pnlg 61 y 6 Narr. Pier Plut. Ste: leucocratic granite-- leucocratic subsolvus granite RI Pnpg 61 y 6 Narr. Pier Plut. Ste: porphyritic granite-- porphyritic subsolvus granite RI Trd 44 u 4 Diabase dikes RI Trvq 34 u 3 Triassic ? age vein quartz Description: En enchelon and crosscutting veins (millimeter to meter widths) of massive quartz RI Zbm 43 u 4 Blackstone Grp: greenstone, amphibolite, serpentinite RI Zbq 34 u 3 Blackstone Grp: quartzite RI Zbs 13 u 1 Blackstone Grp: epidote and biotite schist-- schist, interlayered with quartzite and marble RI Zbu 43 u 4 Blackstone Grp: undifferentiated rock - complex associations of Blackstone rocks cut by granitic rocks of the Esmond Igneous Suite resulting in migmatitic appearence RI Zeag 61 x 6 Esmond Igneous Suite: augen granite gneiss- -gneiss with alkali-feldspar porphyroclasts RI Zefg 61 x 6 Esmond Igneous Suite: fine-grained granite- -aplitic granite RI Zefv 61 x 6 Esmond Igneous Suite: felsic volcaniclastic rock--ash-flow tuff, ignimbrite, and felsite RI Zeg 61 x 6 Esmond Igneous Suite: granite--leucocratic subsolvus granite RI Zegd 61 x 6 Esmond Igneous Suite: granodiorite-- porphyritic granodiorite with phenocrysts of microcline RI Zegg 61 x 6 Esmond Igneous Suite: granite gneiss RI Zem 44 u 4 Esmond Igneous Suite: mafic/intermediate rock--tonalite, quartz diorite, and gabbro RI Zha 61 x 6 Harmony Grp: Absalona Fm--biotite granite gneiss; subordinate schist, amphibolite, and quartzite RI Zhn 61 x 6 Harmony Grp: Nipsachuck Fm--granite gneiss with prominent biotite streaks RI Zhw 61 vx 6 Harmony Grp: Woonasquatucket Fm--felsic gneiss, commonly phyllonitic RI Zms 33 c 3 mica schist--micaceous schist, with minor beds of quartzite, marble, and amphibolite RI Znfa 33 c 3 Newport Grp: Fort Adams Fm--olistoliths of dolostone and quartz arenite within a matrix of tuff, siltstone, slate, and conglomerate RI Znnn 33 u 3 Newport Grp: Newport Neck Fm--feldspathic granule conglomerate and slate RI Znpn 33 u 3 Newport Grp: Price Neck Fm--feldspathic siltstone and sandstone, carbonate conglomerate, and ash-flow tuff and lapilli tuff RI Zp 34 u 3 Plainfield Fm--quartzite and mica schist RI Zsag 61 x 6 Sterling Plutonic Grp: alaskite gneiss-- leucocratic granite gneiss RI Zseg 61 x 6 Granites of SE RI: granite--subsolvus granite RI Zsepg 61 x 6 Granites of SE RI: porphyritic granite: with microcline phenocrysts RI Zsgg 61 x 6 Sterling Plutonic Grp: granite gneiss-- granite gneiss with biotite RI Zsmg 43 u 4 Sterling Plutonic Grp: mafic/intermediate gneiss--biotite gneiss and amphibolite gneiss RI Zwm 43 u 4 Waterford Gr: Mamacoke Fm--amphibolitic gneiss with minor quartzite and calc-silicate rock RI Zwr 61 x 6 Waterford Grp: Rope Ferry Gneiss--tonalitic gneiss interlayered with granitic gneiss and minor amphibolite

Progress: Complete
Update Frequency: None Planned

Theme Keywords: None, Lithogeochemical, Bedrock, NAWQA, NECB, Geology, Geochemical, CONN, Lithology, Mineral, Water chemistry, inlandWaters
Place Keywords: NECB NAWQA study unit, CONN NAWQA study unit, New Hampshire, Maine, Rhode Island, Connecticut, Massachusetts, Kennebec River Basin, Merrimack River Basin, Charles River Basin, Saco River Basin, Androscogginn River Basin, Taunton River Basin, Pawcatuck River Basin

Access Constraints: None
Usage Constraints: The spatial accuracy of the geologic source information varies. The source geologic map scales range from 1:100,000 to 1:500,000. In addition, analysis near State boundaries may be limited by the geologic map interpretation differences across State boundaries. Interpretations combining the NECB NAWQA data set with a similar bordering data set done for the CONN NAWQA (Robinson and others, 1999) are limited by variances related to differences in source materials used and interpretation of geologic information between the CONN and NECB lithochemical mapping. See the Data_Quality_Information section in this metadata file for more information.