|Description||This CD-ROM contains a digital version of the Geologic Map of the United States, originally published at a scale of 1:2,500,000 (King and Beikman, 1974b). It excludes Alaska and Hawaii. In addition to the graphical formats, the map key is included in AS|
|Originators||Schruben, Paul G.; Arndt, Raymond E.; Bawiec, Walter J.; King, Philip B.; and Beikman, Helen M.|
|Publication||U.S. Geological Survey Digital Data Series DDS-11|
Labels of the mapped units described by polygons in the data set are as follows: C,cat,Ce,Cg,Cq,Cv,D,D1,D2,D2c,D3,D3c,De,dike,DS,DSe,DSv,Dv,J, Jc,Jg,Jmi,JTr,Kc,Ke,Kg,Kg1,Kg2,Kg3,Kgn,Ki,Kv,lK,lK1,lK2,lK3, lMz,lMze,lMzv,lPz,lPze,lTa,lTf,lTv,M,M1,M2,M3,mm1,mm2,mm3,mm4, Ms,O,O1,O1a,O1b,O2,O3,OC,Oe,Ov,P,P1,P1c,P2,P2a,P2ac,P2b,P3,P3a, P3b,P4,Pe,PP,PP1,PP1a,PP2,PP3,PP4,Pza,Pzg1,Pzg2,Pzg3,Pzmi,Q, Qf,Qh,Qp,Qv,S,S1,S2,S3,Se,SOe,Sv,Ta,Te,Te1,Te2,Te3,Teb,Tec,Tee, Tel,Ti,Tm,Tmc,Tmf,Tmoe,Tmv,To,Toc,Toee,Tp,Tpc,Tpf,Tpv,Tr,Trg, Tri,TrPe,Trv,Tx,Txc,uK,uK1,uK2,uK3,uK3a,uK3b,uK4,uM,uMze,uPz, uPzc,uPze,uTa,W,Wg,Wgn,Wmi,WTER,Wv,X,Xg,Xm,Xv,Y,Y1,Y2,Y3,Ya, Yg1,Yg2,Ygn,Ym,Ymi,Ys,Yv,Z,Zg,Zv Each line object in the fault coverage has one of four attribute values: 1) faults (label FAULT) 2) dashed fault (label DASH) 3) dotted fault (label DOT) 4) hidden contact (label CONTAC) Full details of the meanings of the attributes are given in USGS Professional Paper 901, whose text is provided with this data set.
U.S. Geological Survey Professional Paper 901 is included with this data set (when distributed in CD-ROM format) in ASCII, with figures in TIFF.
Bedrock formations that are, wherever possible, time-stratigraphic--that is, units which are approximately the same geologic ages at all places, such as systems, series, and stages.
Faults are shown not only to explain offsets of map units, but for their own sake, to express the structural grain of the area. The density of faults represented on the geologic map thus equals that which would appear on a tectonic map of the country, but they are marked simply as faults, not as low-angle or high- angle thrust faults, normal faults, or strike-slip faults; for this information the user should consult the appro- priate tectonic map.