Surficial Materials Broad Brook

Metadata:
Identification_Information:
Citation:
Citation_Information:
Title: Surficial Materials Broad Brook
Online_Linkage: <http://magic.lib.uconn.edu/>
Description:
Abstract:
Geologic Discussion - The following text is excerpted from the text on sheet 1 of the Surficial Materials Map of Connecticut. It has been modified as necessary for use with the 1:24,000 scale digital data, and is not considered a valid substitute for the information found on the published map. For a more complete understanding of the geologic principles behind the Surficial Materials data it is advisable to consult the published map which contains cross sections, diagrams and text not available in digital form. DISCUSSION OF SURFICIAL MATERIALS The unconsolidated deposits overlying bedrock in Connecticut range from a few feet to several hundred feet in thickness. These earth materials significantly affect human development of the land. Most of the unconsolidated materials are deposits of continental glaciers that covered all of New England at least twice during the Pleistocene ice age. These glacial deposits are divided into two broad categories, glacial till and glacial stratified deposits. Till, the most widespread glacial deposit, was laid down directly by glacier ice and is characterized by a non-sorted matrix of sand, silt, and clay with variable amounts of stones and large boulders. Glacial meltwater deposits are concentrated in both small and large valleys and were laid down by glacial meltwater in streams and lakes in front of the retreating ice margin during deglaciation. These deposits are characterized by layers of well-sorted to poorly sorted gravel, sand, silt, and clay. Postglacial sediments, primarily floodplain alluvium and swamp deposits, make up a lesser proportion of the unconsolidated materials of Connecticut. Alluvium is largely reworked from glacial materials and has similar physical characteristics. The distribution of surficial (unconsolidated) materials that lie between the land surface (below the pedogenic soil) and the bedrock surface is shown on this map to the extent that it is known or can be inferred. The cross sections and the block diagram shown on the published map (Stone and others, 1992) illustrate the characteristic vertical distribution of glacial till, glacial meltwater deposits, and postglacial deposits encountered in Connecticut. The areal distribution of till and stratified deposits is related to the physiographic regions of the State: the eastern and western highlands and the central lowland. In highland areas, till is the major unconsolidated material, present as a discontinuous mantle of variable thickness over the bedrock surface. Till is thickest in drumlins and on the northwest slopes of hills. Glacial meltwater deposits that average 10-40 feet in thickness overlie the till in small upland valleys and commonly in north-sloping pockets between bedrock hills. In the central lowland, especially in the north half, glacial stratified deposits are the predominant surficial materials. These deposits generally overlie till; however, well logs indicate that in some places till is not present and the stratified deposits lie directly on bedrock. The extensive stratified deposits of the central lowland average 50-100 feet in thickness, and in the northern part they almost completely mask the till-draped bedrock surface. Postglacial materials locally overlie the glacial deposits throughout the State. Alluvium occurs on the floodplains of most streams and rivers. Swamp deposits occur in poorly drained areas. Talus occurs along the bases of steep bedrock cliffs, principally along the traprock ridges within the central lowland. Salt-marsh and estuarine deposits occur mainly along the tidal portions of streams and rivers entering Long Island Sound. Beach deposits occur along the shoreline of Long Island Sound. The units on this map delineate textural changes in the subsurface as well as areally at the surface. An earlier map at 1:125,000 scale of central Connecticut (Stone and others, 1979) shows only surface textural units; a separate map in the same series (Langer, 1979) shows subsurface deposits of fine-grained materials. Several previous 1:24,000-scale quadrangle maps in Connecticut show three-dimensional textural units and refer to them as "superposed deposits" (see Stone, 1976 and Radway and Schnabel, 1976, as examples). On this map, the term "stack unit" (Kempton, 1981) is used in place of superposed deposits. DISTRIBUTION OF TEXTURES IN GLACIAL MELTWATER DEPOSITS The distribution of textural units is extrapolated from both point data (well and test-hole logs, gravel pits, and shovel holes) and from interpretation of landforms based on the principles of morphosequence deposition and systematic northward ice retreat (Koteff, 1974; Koteff and Pessl, 1981). These concepts provide a model by which grain-size distribution can be predicted from the morphology of a deposit, given primary data about the textures at specific points. A morphosequence is a package of sediments deposited contemporaneously by meltwater flowing from the glacier margin to a specific base level. Within a morphosequence, grain size decreases and sorting improves from the ice-marginal (proximal) end of a deposit downstream to the distal end. Landforms are transitional within a sequence as well, ranging from ice-contact forms (eskers, kettles, kames) at the head (proximal end) of a deposit to uncollapsed forms (delta-foreset slopes, lake-bottom plains, valley trains) downstream (distal end). Coarser grained sediments are associated with the proximal parts of morphosequences, finer grained sediments are associated with distal parts; given this principle, textural distribution can be mapped using point data that serve as controls. The relationship between textural variations and morphosequences is illustrated by a cross section on the published map, which shows the distribution of texture units in the northern Quinnipiac River valley. This north-south section transects seven chronologically numbered morphosequences. Dashed lines drawn to the six southern sequences represent the probable generalized surface gradients of the heads of these deposits, prior to collapse (due to melting of buried ice) and subsequent stream entrenchment. From north to south within each of these sequences, the textures grade from coarse- to fine-grained sediments and the topography changes from collapsed to non-collapsed landforms. The longitudinal and vertical relationships illustrated by this section are common in other valleys as well. Stack units similar to those on the section described above occur throughout the stratified deposits of Connecticut. Many deposits having similar superposition of materials of differing texture were produced by geologic processes that occurred repeatedly in time and space during the deglaciation of Connecticut. For example, the SG/S/F and S/F stack units commonly occur in glacial-lake deltas. The SG/F stack unit commonly results from fluvial meltwater (or postglacial stream) terrace deposition on slightly older lake bottom deposits. The F/SG and S/SG units commonly occur in the distal parts of morphosequences where the sand or fines overlap the collapsed, coarser, proximal parts of other (older) sequences. Many basic texture units (G, SG, S, F) likewise have broadly common origins. Units of gravel or sand and gravel often occur in the proximal parts of deposits, or were commonly laid down in glaciofluvial environments. Units of sand and fine-grained sediment are typically associated with distal parts of sequences and were usually laid down in lacustrine environments. THICKNESS OF MATERIALS The thickness of surficial materials in Connecticut varies considerably because of such factors as the high relief of the bedrock surface, changing conditions of deposition during deglaciation, and various effects of postglacial erosion and removal of glacial sediments. For more information on the thickness of deposits and the point data used to determine stacked units, it is beneficial to review the complete and figures on the published map.
Purpose:
This dataset is meant to show Surficial Materials for decision making.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1990
Range_of_Dates/Times:
Beginning_Date: 19690000
Ending_Date: 19840000
Currentness_Reference:
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Irregular
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -72.625
East_Bounding_Coordinate: -72.5
North_Bounding_Coordinate: 41.875
South_Bounding_Coordinate: 42
Keywords:
Theme:
Theme_Keyword_Thesaurus: FGDC
Theme_Keyword: Digital Line Graphs
Theme_Keyword: DLG
Theme_Keyword: Surficial materials
Theme_Keyword: Unconsolidated materials
Theme_Keyword: Geology
Place:
Place_Keyword_Thesaurus:
Place_Keyword: Broad Brook
Stratum:
Stratum_Keyword_Thesaurus: None
Stratum_Keyword: None
Temporal:
Temporal_Keyword_Thesaurus: None
Access_Constraints: None
Use_Constraints: None
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Howie Sternberg
Contact_Organization_Primary:
Contact_Organization:
Natural Resources Center, Dept. of Environmental Protection, Connecticut.
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Natural Resources Center
Address: Dept. of Environmental Protection.
Address: 79 Elm St.
City: Hartford
State_or_Province: CT
Postal_Code: 06106-5127
Contact_Voice_Telephone: (860) 424-3540
Contact_Facsimile_Telephone: (860) 424-4058
Contact_Electronic_Mail_Address: howard.sternberg@po.state.ct.us
Hours_of_Service: 8:00 a.m. to 4:00 p.m. Monday Through Friday
Contact_Instructions: Unavailable
Native_Data_Set_Environment: UNIX-ARC/INFO
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
Conforms to Connecticut Department of Environmental Protection DEP-GIS Spatial Data Standards.
Logical_Consistency_Report:
Conforms to Connecticut Department of Environmental Protection DEP-GIS Database Design Standards
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: Not determined
Lineage:
Source_Information:
Source_Citation:
Source_Scale_Denominator: 24000
Type_of_Source_Media: Magnetic Tape
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1990
Range_of_Dates/Times:
Beginning_Date: 1948
Ending_Date: 1991
Source_Currentness_Reference:
Source_Citation_Abbreviation: None
Source_Contribution: None
Process_Step:
Process_Description:
Digital Automation - Surficial materials digital data produced by the CT Dept. of Environmental Protection with support from the U.S. Geological Survey, the U.S. Environmental Protection Agency, and the CT Department of Public Health and Addiction Services. Original mapping at 1:24,000 scale by the U.S. Geological Survey in cooperation with the Connecticut Department of Environmental Protection, Geological and Natural History Survey. Data manually digitized from 1:24,000-scale mylar quadrangle compilation sheets (on file at the Natural Resources Center, DEP) prepared for the Surficial Materials Map of Connecticut, 1:125,000 scale, Stone and others, 1992. Topographic bases used in the original geologic compilation from USGS 1:24,000 scale revisions 1952-1970. Digital compilation utilized hydrography from 7.5 minute, 1:24,000 scale U.S. Geological Survey Digital Line Graph source material (1969-1984) with minor modification of geologic contacts to fit the revised hydrography where necessary. Hydrography selected from the USGS Digital Line Graph data (code numbers 050 0412,050 0421, and 050 0116) include streams, lakes, ponds, bays, estuaries, and seas with areas greater than 5 acres. Units shown on the quadrangle maps are typically those of the 1:125,000-scale State Map. Additional map units may be present in the digital data that could not be readily shown on the published map at 1:125,000 scale or that represent more recent mapping, particularly along the coast. Some subsurface information as noted by stacked units may also be more detailed in the digital data than that of the published State Map.
Source_Used_Citation_Abbreviation: None
Process_Date: Unknown
Process_Time: Unknown
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Howie Sternberg
Contact_Organization_Primary:
Contact_Organization:
Natural Resources Center, Dept. of Environmental Protection, Connecticut.
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Natural Resources Center
Address: Dept. of Environmental Protection.
Address: 79 Elm St.
City: Hartford
State_or_Province: CT
Postal_Code: 06106-5127
Contact_Voice_Telephone: (860) 424-3540
Contact_Facsimile_Telephone: (860) 424-4058
Contact_Electronic_Mail_Address: howard.sternberg@po.state.ct.us
Hours_of_Service: 8:00 a.m. to 4:00 p.m. Monday Through Friday
Contact_Instructions: Unavailable
Process_Step:
Process_Description:
Quadrangle Edge matching - Edge matching was performed in a way consistent with other DEP GIS data layers. Arcs crossing quadrangle boundaries were individually edge matched and visually checked for accuracy. Beginning with quadrangle 1 in the Northwest corner of Connecticut, features were edge matched to line up with corresponding features on adjacent quadrangles through a process of checkerboard edge matching. Every other quadrangle was adjusted such that arcs were snapped to connect with the corresponding stationary features on adjacent quadrangles. Edge matching was successfully completed once it was possible to append the individual quadrangle coverages and assemble a statewide coverage with polygons that closed.
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Howie Sternberg
Contact_Organization:
Natural Resources Center, Dept. of Environmental Protection, Connecticut.
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: Mailing and Physical Address
Address: Natural Resources Center
Address: Dept. of Environmental Protection.
Address: 79 Elm St.
City: Hartford
State_or_Province: CT
Postal_Code: 06106-5127
Contact_Voice_Telephone: (860) 424-3540
Contact_Facsimile_Telephone: (860) 424-4058
Contact_Electronic_Mail_Address: howard.sternberg@po.state.ct.us
Hours_of_Service: 8:00 a.m. to 4:00 p.m. Monday Through Friday
Contact_Instructions: Unavailable
Process_Step:
Process_Description:
Processing in MAGIC: Data were supplied to the Map and Geographic Information Center (MAGIC) by the data producer, Natural Resource Center, ConnDEP as uncompressed E00 files and as DXF files. The E00 files were tranformed to MIF files using MapInfo's ArcLink utility. ConnDEP is the sole authority of content of the dataset.
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Map and Geographic Information Center
Contact_Position: Map Librarian
Contact_Address:
Address_Type: Mailing Address
Address: MAGIC U-5m
Address: Homer Babbidge Library
Address: 369 Fairfield Rd.
City: Storrs
State_or_Province: CT
Postal_Code: 06269
Contact_Voice_Telephone: (860) 486-4589
Hours_of_Service: 9-12, 1-5 M-F, 18:30-21:30 M-W
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name:
State_Plane_Coordinate_System:
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 600
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
most extensive till and is commonly observed in surface exposures, especially in areas where till thickness is less than 15 ft; it is described in the thin till unit description below. The lower till or "old" till was deposited during an earlier glaciation (probably Illinoian). The lower till has a more patchy distribution; it is principally a subsurface deposit, generally overlain by upper till, and therefore not shown as a separate map unit; the lower till does however constitute the bulk of material in the areas where till thickness is greater than 15 ft; it is described in the thick till unit description below. In all two-till exposures, the base of the upper till truncates the weathered surface of the old till. The lower part of the upper till commonly displays a zone of shearing, dislocation, and brecciation in which clasts of lower till are mixed and incorporated into the upper till. End moraine deposits occur principally in southeastern Connecticut. These deposits were laid down by ablation processes along active ice margins during retreat of the last (late-Wisconsinan) ice sheet. T Thin till-- areas where till is generally less than 10-15 ft thick and including areas of bedrock outcrop where till is absent. Predominantly upper till; loose to moderately compact, generally sandy, commonly stony. Two facies are present in some places; a looser, coarser-grained ablation facies, melted out from supraglacial position; and a more compact finer-grained lodgement facies deposited subglacially. In general, both facies of upper till derived from the red Mesozoic sedimentary rocks of the central lowland of Connecticut are finer-grained, more compact, less stony and have fewer surface boulders than upper till derived from crystalline rocks of the eastern and western highlands. TT Thick till-- areas where till is greater than 10-15 ft thick and including drumlins in which till thickness commonly exceeds 100 ft (maximum recorded thickness is about 200 ft). Although upper till is the surface deposit, the lower till constitutes the bulk of the material in these areas. Lower till is moderately to very compact, and is commonly finer-grained and less stony than upper till. An oxidized zone, the lower part of a soil profile formed during a period of interglacial weathering, is generally present in the upper part of the lower till. This zone commonly shows closely-spaced joints that are stained with iron and manganese oxides. TS End moraine deposits-- Composed predominantly of ablation facies sandy upper till; lenses of stratified sand and gravel occur locally within the till. Surface boulders on end moraine deposits are generally more numerous than on adjacent till surfaces; dense concentrations of boulders are present in some places. Deposits occur as free-standing hummocky landforms, commonly in elongate ridges that trend NNE - SSW, and range in thickness from 10 to 60 ft. GLACIAL MELTWATER DEPOSITS Glacial meltwater deposits (stratified deposits) consist of layers of well-sorted to poorly sorted gravel, sand, silt, and clay laid down by flowing meltwater in glacial lakes and streams which occupied the valleys and lowlands of Connecticut during retreat of the last ice sheet. Textural variations within the meltwater deposits occur both areally and vertically because meltwater-flow regimes were different in glaciofluvial (stream), glaciodeltaic (where a stream entered a lake), and glaciolacustrine (lake bottom) depositional environments. Grain-size variations also resulted from meltwater deposition in positions either proximal to or distal from the retreating glacier margin, which was the principal sediment source. A common depositional scenario contained a proximal, ice-marginal meltwater stream in which horizontally bedded glaciofluvial gravel and/or sand and gravel were laid down; farther down valley, the stream entered a glacial lake where glaciodeltaic sediments were deposited consisting of horizontally layered sand and gravel delta-topset beds overlying inclined layers of sand in delta-foreset beds. Farther out in the glacial lake, glaciolacustrine very fine sand, silt, and clay settled out on the lake bottom in flat-lying, thinly bedded layers. Mappable textural variations are present in the vertical section of meltwater deposits in many places. This stacking of textural units commonly resulted from locally changing conditions of meltwater deposition. For example, glacial lakes drained upon ice retreat from particular positions. This may have been followed locally by distal glaciofluvial (stream) deposition from ice positions farther up valley. The resulting vertical section shows meltwater terrace sediments consisting of horizontally bedded fluvial sand and gravel which overlie lake-bottom sediments of very fine sand, silt and clay (shown as unit SG/F on the map). In other places glaciodeltaic deposition over an extended period of time in a particular glacial lake caused deltaic deposits (sand and gravel topset beds over sand foreset beds, unit SG/S) to prograde farther out into the lake and to overlie lake-bottom sediments; such deposits are shown as stack unit SG/S/F on the map. Meltwater deposits are shown on this map as four basic units: gravel, sand and gravel, sand, and fines. Grain-size terminology used to define the textural range within these units is modified from Wentworth, 1922. Stack units are also shown; these are combinations of the four basic units in various orders of superposition. The map units described below show the texture of meltwater deposits through the total vertical section to the extent that it is known or can be reasonably inferred. In some places only one textural unit (such as unit SG) describes the entire vertical thickness of the meltwater deposits. In other places stack units (such as units SG/S/F or S/F) indicate changes of textural units in the subsurface. Common depositional environments for each textural unit are given in parentheses after each unit description. Fine Deposits F Fines (very fine sand, silt, and clay)-- Composed of well-sorted, thin layers of alternating silt and clay, or thicker layers of very fine sand and silt. Very fine sand commonly occurs at the surface and grades downward into rhythmically bedded silt and clay varves (lake-bottom deposits) Coarse Deposits G Gravel-- Composed mainly of gravel-sized particles; cobbles and boulders predominate; minor amounts of sand within gravel beds, and sand comprises few separate layers. Gravel layers generally are poorly sorted and bedding commonly is distorted and faulted due to postdepositional collapse related to melting of ice. Gravel deposits are shown only where observed in the field; additional gravel deposits may be expected, principally in areas mapped as unit sg (proximal fluvial deposits or delta-topset beds) SG Sand and gravel-- Composed of mixtures of gravel and sand within individual layers and as alternating layers. Sand and gravel layers generally range from 25 to 50 percent gravel particles and from 50 to 75 percent sand particles. Layers are well to poorly sorted; bedding may be distorted and faulted due to postdepositional collapse. It is likely that some deposits within this map unit actually are gravel or sand and gravel overlying sand. It is less likely that some of these deposits are sand (fluvial deposits or delta-topset beds) S Sand-- Composed mainly of very coarse to fine sand, commonly in well-sorted layers. Coarser layers may contain up to 25 percent gravel particles, generally granules and pebbles; finer layers may contain some very fine sand, silt, and clay (delta-foreset beds, very distal fluvial deposits, or windblown sediment) Stacked Coarse Deposits G/SG Gravel overlying sand and gravel-- Gravel is generally less than 20 ft thick, horizontally bedded, and overlies thicker, inclined layers of sand and gravel (proximal deltaic deposits) G/S Gravel overlying sand-- Gravel is generally less than 20 ft thick, horizontally bedded, and overlies thicker, inclined layers of sand (proximal deltaic deposits) SG/S Sand and gravel overlying sand-- Sand and gravel is generally less that 20 ft thick, horizontally bedded, and overlies thicker, inclined layers of sand (deltaic deposits) SG/S/SG Sand and gravel overlying sand overlying sand and gravel-- Sand and gravel is generally less than 20 ft thick, horizontally bedded, and overlies thicker inclined layers of sand; thickness of sand and gravel at the base of the section is variable (deltaic deposits overlying slightly older, more proximal deposits) S/G Sand overlying gravel-- Sand of variable thickness overlies gravel of variable thickness (younger distal deltaic or fluvial sediments overlying older, more proximal fluvial or deltaic sediments) S/SG Sand overlying sand and gravel-- Sand of variable thickness overlies sand and gravel of variable thickness (distal deltaic or fluvial sediments overlying slightly older proximal fluvialor deltaic sediments) Stacked Coarse Deposits Overlying Fine Deposits G/S/F Gravel overlying sand overlying fines-- Gravel is generally less than 20 ft thick, horizontally bedded and overlies thicker inclined beds of sand which in turn overlie fines of variable thickness (proximal deltaic deposits overlying lake-bottom sediments) G/F Gravel overlying fines-- Gravel is generally less than 20 ft thick, horizontally bedded and overlies thicker thinly bedded fines (proximal fluvial deposits overlying lake-bottom sediments) SG/S/F Sand and gravel overlying sand overlying fines-- Sand and gravel is generally less than 20 ft thick, horizontally bedded and overlies thicker inclined beds of sand which in turn overlie thinly bedded fines of variable thickness (deltaic deposits overlying lake-bottom sediment) SG/F Sand and gravel overlying fines-- Sand and gravel is generally less than 20 ft thick, horizontally bedded and overlies thicker thinly bedded fines (fluvial meltwater terrace deposits overlying lake-bottom sediment) S/F Sand overlying fines-- Sand is of variable thickness, commonly in inclined foreset beds and overlies thinly bedded fines of variable thickness (distal deltaic deposits overlying lake-bottom sediment) Stacked Fine Deposits Overlying Coarse Deposits F/SG Fines overlying sand and gravel-- Fines of variable thickness, commonly in thinly bedded layers overlie sand and gravel of ariable thickness (lake-bottom deposits overlying slightly older collapsed proximal fluvial or deltaic deposits); in a few places sand or sand and gravel, generally less than 25 ft thick occurs on top of the f/sg unit and is indicated as s/f/sg and sg/f/sg on the map, respectively F/S Fines overlying sand-- Fines of variable thickness, commonly in thinly bedded layers overlie sand of variable thickness (distal lake-bottom deposits overlying slightly older more delta-proximal lacustrine sediment) POSTGLACIAL DEPOSITS A Floodplain alluvium-- Sand, gravel, silt, and some organic material, on the floodplains of modern streams. The texture of alluvium commonly varies over short distances both laterally and vertically, and is often similar to the texture of adjacent glacial deposits. Along smaller streams, alluvium is commonly less than 5 ft thick. The most extensive deposit of alluvium on the map is along the Connecticut River where the texture is predominantly fine to very fine sand and silt; here and along other larger rivers, it may be as much as 25 ft thick. Alluvium typically overlies thicker glacial stratified deposits, the general texture of which is indicated by the stacked unit. A/SG Alluvium overlying undifferentiated coarse deposits A/S Alluvium overlying sand A/F Alluvium overlying fines A/SG/F Alluvium overlying undifferentiated coarse deposits overlying fine deposits A/S/F Alluvium overlying sand overlying fines A/F/SG Alluvium overlying undifferentiated fine deposits overlying coarse deposits A/F/S Alluvium overlying fines overlying sand SW Swamp deposits-- Muck and peat that contain minor amounts of sand, silt, and clay, accumulated in poorly drained areas. Most swamp deposits are less than about 10 ft thick. Swamp deposits are underlain by glacial deposits or bedrock. They are often underlain by glacial till even where they occur within glacial meltwater deposits. Where swamp deposits are known or inferred to be underlain by sand and/or fines, they are shown on the map by the stacked unit. SW/SG Swamp deposits overlying undifferentiated coarse deposits SW/S Swamp deposits overlying sand SW/F Swamp deposits overlying fines SW/S/SG Swamp deposits overlying sand overlying undifferentiated coarse deposits SW/S/F Swamp deposits overlying sand overlying fines SW/F/S Swamp deposits overlying fines overlying sand SM Salt-marsh and tidal-marsh deposits-- Peat and muck interbedded with sand and silt, deposited in environments of low wave energy along the coast and in river estuaries. Marsh deposits are dominantly peat and muck, generally a few feet to 35 ft thick. In the major estuaries marsh deposits may overlie estuarine deposits which are sand and silt with minor organic material as much as 40 - 90 ft thick. These deposits are generally underlain by the glacial material shown adjacent on the map; either till or sand and gravel. Where they are known or inferred to be underlain by sand or fines, they are shown on the map by stacked units. SM/S Salt-marsh and tidal-marsh deposits overlying sand SM/F Salt-marsh and tidal-marsh deposits overlying fines SM/S/F Salt-marsh and tidal-marsh deposits overlying sand overlying fines TA Talus-- Loose, angular blocks (mostly boulders) accumulated by rockfall at the bases of steep bedrock cliffs. Talus forms steep unstable slopes and is generally less than 10 ft thick. It occurs most extensively along the linear basalt and diabase ridges within the central lowland. B Beach deposits-- Sand and and gravel deposited along the shoreline by waves and currents and by wind action. The texture of beach deposits varies over short distances and is generally controlled by the texture of nearby glacial materials exposed to wave action. Beach deposits are generally well sorted and rarely more than a few feet thick. Many sand beaches along the Connecticut coast have been "restored"; these have not been distinguished from natural beaches on this map; however, extensive beaches that consist totally of "made-land" are mapped as artificial fill. AF Artificial fill-- Earth materials and manmade materials that have been artificially emplaced. Artificial fill is common throughout the map area but has been shown on this map only where extensive areas of "made land" occur, principally along the coast.
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Map and Geographic Information Center
Contact_Position: Map Librarian
Contact_Address:
Address_Type: Mailing Address
Address: MAGIC U-5m
Address: Homer Babbidge Library
Address: 369 Fairfield Rd.
City: Storrs
State_or_Province: CT
Postal_Code: 06269
Contact_Voice_Telephone: (860) 486-4589
Hours_of_Service: 9-12, 1-5 M-F, 18:30-21:30 M-W
Distribution_Liability:
MAGIC is charged with the distribution of the State's corporate geographic database and, in cooperation with other mapping organizations, is committed to offering its users accurate, useful, and current information about the state. Although every effort has been made to ensure the accuracy of information, errors and conditions originating from physical sources used to develop the corporate database may be reflected in the data supplied. The client must be aware of data conditions and bear responsibility for the appropriate use of the information with respect to possible errors, original map scale, collection methodology, currency of data, and other conditions specific to certain data. MAGIC endorses but does not support secondary distribution of this data.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ARC/INFO
Format_Version_Number: Version 7.1
Format_Specification: None
Format_Information_Content: None
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://magic.lib.uconn.edu/g/37811/surf/s24/ctdep/surf.37811.0023.1992.s24.ctdep.1.e.zip>
Fees: None
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: MIF
Format_Version_Number: Ver. 3
Format_Specification: None
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
<http://magic.lib.uconn.edu/g/37811/surf/s24/ctdep/surf.37811.0023.1992.s24.ctdep.1.m.zip>
Metadata_Reference_Information:
Metadata_Date: 20000412
Metadata_Contact:
Metadata_Standard_Name:
FGDC Content Standards For Digital Geospatial Metadata
Metadata_Standard_Version: June 8, 1994
Metadata_Access_Constraints: None
Metadata_Use_Constraints: None
Metadata_Security_Information:
Metadata_Security_Classification_System: None
Generated by mp version 2.2.6 on Wed Apr 12 14:08:58 2000