Geologic map of the Sedan quadrangle, Gallatin and Park Counties, Montana

Online link https://geo-nsdi.er.usgs.gov/metadata/map-i/2634/metadata.faq.html
Description This quadrangle lies 6.4 km (4 mi) northeast of Bozeman, Mont., in southwestern Montana. Metamorphic, sedimentary, and volcanic rocks of Precambrian to Tertiary age are exposed in the Bridger Range and southwestern margin of the Crazy Mountains Basin in
Originators Skipp, Betty A.; Lageson, D. R.; and McMannis, W. J.

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States or counties

geo_net.pat

Polygons in the coverage geo_net

Label Definition
GEOCODE Type of geologic feature. Character, width 40.
NAM Map unit name and associated symbol (ASCII character set does not include special symbol for Cambrian, requiring substitution of the letter "C" for the Cambrian symbol). Character, width 14.

geo_net.aat

Arcs in geo_net coverage.

Label Definition
GEOCODE_L Type of geologic feature. Character, width 40.
ACC Accuracy of located contacts. Integer.

geo_pnt.pat

Point features in geo_pnt coverage. These describe orientation of bedding in sedimentary rocks and orientation of eutaxitic layering in ash-flow tuffs.

Label Definition
GEOCODE Type of surface for which orientation is given. Character, width 40.
STK Measured strike in degrees. Integer.
DIP Measured dip in degrees. Integer. NOTE: The info files give the azimuth for strike and the value for dip; the direction of dip is not readily apparent from the info files. The user should refer to the plotted graphic to determine direction of dip.
POS Position of the bedding in sedimentary rocks or position of eutaxitic layering in ash-flow tuffs. Integer.
ACC Accuracy, meaning whether the orientation of beds or the layering was measured or estimated. Integer.
CON Integer indicating whether the bedding surface in sedimentary rocks is crumpled.

stru_net.aat

Arcs in stru_net coverage. The direction of the arcs is significant in that it determines on which side the sawteeth or half circles are placed on the thrust and detachment faults. The sawteeth or half circles are on the upper plate. If these coverages are cleaned the arcs can 'flip' and the sawteeth or half circles will end up on the incorrect side of the fault. Please refer to the graphic file for correct placement of sawteeth or half circles.

Label Definition
GEOCODE Type of feature. Character, width 40.
TYP Type of fault or fold. Integer.
ACC Accuracy of location of faults and folds.
DIR Sense of relative movement on normal or oblique slip faults or to sense of oblique slip on thrust faults.
POS Position of the axial surface of folds.

stru_pnt.pat

Point features in stru_pnt coverage. These describe orientation of layering in metamorphic rocks.

Label Definition
GEOCODE Type of surface for which orientation is given. Character, width 40.
STK Measured strike of layering in metamorphic rocks, in degrees. Integer.
DIP Measured dip of layering in metamorphic rocks, in degrees. Integer. NOTE: The info files give the azimuth for strike and the value for dip; the direction of dip is not readily apparent from the info files. The user should refer to the plotted graphic to determine direction of dip.
POS Position of the layering in metamorphic rocks. Integer.
ACC Accuracy, meaning whether the orientation of layering was measured or estimated. Integer.

data_net.aat

Lines of the data_net coverage form the quadrangle boundary and lines of section.

Label Definition
GEOCODE Type of line. Character, width 40.
XTA Identity of the cross section, if GEOCODE value is Xsection, blank otherwise. Character, width 30.

data_pnt.pat

Points in coverage data_pnt are locations for gravel pits, test wells, and springs.

Label Definition
GEOCODE Type of feature. Character, width 40.

pnt_sym.pat

Points in coverage pnt_sym locate arrows for faults and folds and U and D symbols for faults. (NOTE: On this map the "U" indicates the APPARENT upthrown side of a thrust fault and "D" the APPARENT downthrown side. Please refer to the graphic file for correct placement of sawteeth that indicate the upper plate.

Label Definition
TYP Type of symbol. Character, width 10. NOTE: NORMAL/D and NORMAL/U as used here also include "U" and "D" on thrust faults.)