U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Bedrock Geologic Map of the Windham Quadrangle, Rockingham and Hillsborough Counties, New Hampshire [scale 1:24,000] by Gregory J. Walsh (1) and Stewart F. Clark, Jr. (1) Open-File Report OF-99-8-A Map (paper map and text) OF-99-8-B Database (computer files) 1999 version 1.0 Prepared in cooperation with the New Hampshire Department of Environmental Services, Water Division This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards (or with the North American Stratigraphic Code). Any use of trade, product, or firm names is for descriptive purposes only and does not constitute endorsement by the USGS. Although this database has been used by the U.S. Geological Survey, no warranty, expressed or implied, is made by the USGS as to the accuracy and functioning of the database and related program material, nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith. ________________________________ (1) U.S. Geological Survey Montpelier, Vermont 05601 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Source of Geologic Data: Original data. Geology mapped by Walsh and Clark in the summer of 1998 at a scale of 1:24,000. The bedrock geology was mapped using standard techniques. Locational information was provided by Rockwell PLGR+96 GPS receivers using the Federal precise positioning service. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Contents of this report: 1 - 34" tall x 66" wide colored paper map, scale 1:24,000 1 - 18 page black and white text on 8.5" by 11" paper (PDF format) 1 - database of Arc/Info files, supporting files, and metadata This report (OF-99-8) is available from: WWW: http://pubs.usgs.gov/openfile/of99-8/ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description: The bedrock geology of the 7.5-minute Windham quadrangle, New Hampshire consists of deformed early Paleozoic crystalline metamorphic and intrusive igneous rocks intruded by Mesozoic igneous dikes. The geology was mapped during the summer of 1998 at a scale of 1:24,000. The bedrock geology was mapped using standard techniques. Locational information was provided by Rockwell PLGR+96 GPS receivers using the federal precise positioning service. The line and polygon data were compiled on a mylar greenline of the 7.5-minute quadrangle and scanned at 400 dpi on an Anatech Eagle 4080T scanner. The raster files (TIF) were converted to vector files (DXF) using GTX OSR version 2.0 raster-to-vector conversion software. The vector files were imported to Arc/Info version 7.0.4. Point data were collected with GPS and hand-held 3COM Palm Pilot III PDA computers. Data from the PDAs were combined in Microsoft Access, and then imported as ASCII text files and DBASE IV (dbf) files into Arc/Info. The Arc/Info coverages were registered and transformed to the New Hampshire State Plane Coordinate system. Direct questions or comments on the geology to: Gregory Walsh or Stewart Clark USGS, P.O. Box 628, Montpelier, VT 05601 Direct questions or comments on the database to: Gregory Walsh e-mail: gwalsh@usgs.gov ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Date of latest revision: April 16, 1999 This database was created in ARC/INFO version 7.0.4 on a Data General server running DG/UX 5.4. Digitized by Walsh, Clark, and James Reddy (USGS, Reston, Virginia). ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Note on Metadata: Metadata files exist for each of the individual coverages. The files are available in html format at the website listed above, or as part of the Arc/Info coverage. Use the Arc: "document" command to view the metadata in Arc/Info. Metadata files were created with DOCUMENT.AML version 2.0.2. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Digital data are in the New Hampshire stateplane coordinate system (NAD83) and unprojected geographic coordinates (NAD27). Digital map units in feet (stateplane) and decimal degrees (geographic). ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Computer Files: Note on file naming convention-- The filenames that end in "198" are coverages that are projected in the New Hampshire stateplane coordinate system. The files without the 198 are unprojected coverages in geographic coordinates. The files were archived using UNIX tar and compressed using UNIX gzip. You can use UNIX utilities to extract the data or use WinZip. Useful URLs: http://www.gzip.org http://winzip.com BRIEF DESCRIPTION OF FILES: of998.tar.gz database files in geographic coordinates of998198.tar.gz database files in NH SPCS readme.txt ASCII text description file (this file) of998.ps.gz compressed PostScript file of map (sheet 1 of 1) of998pam.pdf Adobe Portable Document Format of text pamphlet of998.gra.gz Arc/Info graphics file of map metadata.txt ASCII metadata for entire report * * individual metadata files located in each coverage Contents of of998.tar.gz: alcwrg.lin contx.e00 fnt025 fnt038 fnt039 fnt040 geology.mrk joint.e00 lines.e00 outcx.e00 point.e00 readme.txt strux.e00 topo.e00 Contents of of998198.tar.gz: alcwrg.lin contx198.e00 fnt025 fnt038 fnt039 fnt040 geology.mrk joint198.e00 lines198.e00 outcx198.e00 point198.e00 readme.txt strux198.e00 topo198.e00 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Description of the files: GEOLOGIC COVERAGES: In ARC/INFO Interchange Format *.e00; use the arc: IMPORT command to restore. Polygon coverage for the contacts of geologic map units CONTX.E00 CONTX198.E00 Point coverage for brittle structural data (used for cartography) JOINT.E00 JOINT198.E00 Line coverage for axial traces, isograds, and cross-section lines LINES.E00 LINES198.E00 Polygon coverage for outcrops OUTCX.E00 OUTCX198.E00 Point coverage for all structural data (original data set) POINT.E00 POINT198.E00 Point coverage for ductile structural data (used for cartography) STRUX.E00 STRUX198.E00 BASE MAP COVERAGE: Line coverage for topography. Elevation is not attributed. Intended for use as a base map only. TOPO.E00 TOPO198.E00 Other base map coverages shown on Plate 1 are published elsewhere, and were obtained from the New Hampshire GRANIT system available at: http://nhresnet.sr.unh.edu/granit/data/byfunction.html They include: Hydrography Roads Railroads Political boundaries SUPPORTING FILES: readme.txt (This ASCII text file) SYMBOLSETS AND FONT FILES: MARKERSET file (copy to any directory, specify a path when using) geology.mrk LINESET file (copy to any directory, specify a path when using) alcwrg.lin FONT FILES (copy to the same workspace as the coverages) fnt025 fnt038 fnt039 fnt040 The symbolsets and font files are modified from the original versions of Fitzgibbon and Wentworth (1991): Fitzgibbon, T.T., and Wentworth, C.M., 1991, ALACARTE User Interface: AML code and demonstration maps, USGS Open-File report 91-587. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The geologic unit polygons in the CONTX and CONTX198 coverages were filled with colors from the colornames.shd shadeset in Arc/Info. A lookup table was created in Arc/Info to fill the polygons. The lookup table contains the items CODE and SYMBOL. Here is the content of the lookup table: CODE SYMBOL Dg 112 Dmg 104 Dp 119 Md 83 Mdp 105 SOb 19 SObq 94 SObw 20 Sad 84 Sag 17 Sagd 14 Sagdg 25 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The following is a brief description of the ARC/INFO coverages; consult the metadata files for detailed descriptions: CONTX coverage: Item CODE in CONTX.PAT contains the map unit designators. (SObw, Md, etc.) Item LBLTXT in CONTX.PAT is used for selective plotting of code labels; valid entry is 'n' or item is left blank. Item TYPE is a general category of rock type: m=metamorphic and p=plutonic Item TYPE in CONTX.AAT is used for plotting different line types. Valid entries are "concealed" where contacts are under water, or item is left blank. Concealed plotted as dotted line. Blank plotted as solid line. Look-up table CONTX.LUT contains the following items: CODE = map unit designator AGE_SORT = a relative number used to sort the units by age FORMATION = the formation name AGE = geologic age of the map unit MAP_UNIT = simplified description of rock type(s) (Complete description is in the accompanying text) Structural geology point coverages POINT, STRUX and JOINT: Coverage POINT contains all of the structural data points and the points in the database are located within the polygons in the outcrop coverage -- the point locations are the original mapped locations. Coverages STRUX and JOINT contain the ductile and brittle structural data, respectively, and were used for cartography only. The locations of the points in STRUX and JOINT have been moved from the original locations in POINT for plotting purposes. Any spatial analysis should use the POINT coverage data. The STRUX and JOINT coverages also contain annotation for dip and plunge values, and U and D for brittle fault displacement. The annotation is not present in the POINT coverage. The PAT files for the point coverages contain the following user-defined items: ITEM NAME STATION number of field station POSFMT position format from PLGR+96 GPS unit ZONE UTM zone from PLGR+96 GPS unit HDATUM horizontal datum from PLGR+96 GPS unin HRZERR horizontal error from PLGR+96 GPS unit ELEV elevation from PLGR+96 GPS unit VDATUM vertical datum from PLGR+96 GPS unit ELEVUNIT elevation unit from PLGR+96 GPS unit Note on HRZERR -- The database includes the horizontal accuracy of point features as measured and recorded by the PLGR+96 GPS unit. The stated accuracy of the PLGR+96 is +/- 52 feet. For the purposes of cartographic clarity, however, some point data have been moved from their original location to avoid overprint in the STRUX and JOINT coverages. Points located outside of an outcrop polygon have been moved for this reason. Note on POSFMT through ELEVUNIT -- These fields are recorded by the PLGR+96 GPS unit. In the PAT files, some points do not have entries in these fields. These points have been located without the use of GPS. The following items are described in more detail below: TYPE SUB_TYPE STRIKE units in degrees DIP units in degrees DIPDIR units in degrees REL_AGE SYMBOL SYMBOL_ANG units in degrees ROTATION SPACING units in meters WIDTH units in meters NETSLIP units in meters APERTURE units in meters MIN1 MIN2 MIN3 TOPOFEAT CODE relate item for dikes, same as code in CONTX.PAT and LUT ............................................................. Here is the detailed explanation of some of the items: DIP = dip value (planar data) or plunge value (linear data) STRIKE = measured from north in right-hand rule (planar data) DIPDIR = Direction of dip (planar data) or trend (linear data) measured from north For STRIKE and DIPDIR: 0 North = 0 | East = 90 270 -----|----- 90 South = 180 | West = 270 180 SYMBOL_ANG = refers to a standard cartesian angle measured from EAST: 90 North = 90 | East = 0 180 -----|----- 0 South = 270 | West = 180 270 SYMBOL_ANG is used for symbol rotation. In ARC/INFO calculate pseudo item $angle = symbol_ang Planar symbols with symbol_ang = 0 look like this: __________ \/ Linear symbols with symbol_ang = 0 look like this: -----> SYMBOL refers to a pattern number in GEOLOGY.MRK. ROTATION refers to the rotation sense of minor folds as viewed down plunge or offset on minor faults. Valid entries are: clockwise (right-lateral) = cw counterclockwise (left-lateral) = cc REL_AGE refers to the relative age of fabrics. Valid entries are: n-1, n, n+1, n+2, etc. TYPE refers to the general type of symbol. Valid entries are: planar, linear, or other SUB_TYPE refers to the specific symbol. Valid entries used in this report arranged by TYPE: STRUX coverage: TYPE SUB_TYPE REL_AGE SYMBOL CODE DIP linear fold axis n 120 1-89 linear fold axis n+1 115 1-89 linear fold axis n+1 120 1-89 linear fold axis n+2 59 1-89 linear glacial striations 63 linear intersection lineation n 118 1-89 linear intersection lineation n+1 119 1-89 linear refolded fold axis n-1 54 1-89 other quarry 77 other spring 471 planar axial surface n 29 1-89 planar axial surface n 30 90 planar axial surface n+1 40 1-89 planar axial surface n+1 41 90 planar axial surface n+2 44 1-89 planar bedding 1 1-89 planar bedding 2 90 planar bedding with tops 8 1-89 planar bedding with tops 9 90 planar cleavage n+1 14 1-89 planar cleavage n+2 35 90 planar deformed schistosity n 24 1-89 planar dike 97 Sagd planar dike 444 Dp 1-89 planar dike 445 Dp 90 planar dike 473 Dp planar dike 544 Dg 1-89 planar dike 545 Dg 90 planar dike 573 Dg planar dike 644 Md 1-89 planar dike 644 Mdp 1-89 planar dike 645 Md 90 planar dike 645 Mdp 90 planar dike 673 Mdp planar gneissosity n 14 1-89 planar kink band n+1.5 106 1-89 planar kink band n+1.5 107 90 planar layer parallel schistosity 32 1-89 planar layer parallel schistosity 33 90 planar layer parallel schistosity n 32 1-89 planar layer parallel schistosity n 33 90 planar overturned bedding 6 1-89 planar refolded axial surface n-1 26 1-89 planar schistosity n 20 1-89 planar schistosity n 21 90 planar schistosity n+1 14 1-89 planar schistosity n+1 15 90 planar vein 89 JOINT coverage: linear slickensides 123 planar normal fault 125 1-89 planar reverse fault 125 1-89 planar fault 125 1-89 planar joint 10 1-89 planar joint 11 90 planar joint 610 1-89 planar joint 611 90 planar fracture zone 90 1-89 planar fracture zone 91 90 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The following are used in the JOINT coverage: SPACING spacing of joints in joint sets in meters WIDTH width of fracture zone in meters NETSLIP net slip of minor faults in meters APERTURE aperture of joint openings in meters The following are used in the JOINT coverage to describe minerals on joint surfaces and in the STRUX coverage to describe vein minerals: MIN1 primary mineral MIN2 secondary mineral MIN3 tertiary mineral The following values are used in the report, some were modified after Kretz (1983): cal calcite qtz quartz sul sulfides zeo zeolites Kretz, R., 1983, Symbols for rock-forming minerals: American Mineralogist, v. 68, nos. 1-2, p. 277-279. TOPOFEAT topographic feature parallel to geologic structure Values used in this report include: valley cliff stream ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ end