All coverages contain the standardized attributes for arcs and polygons assigned by ARC/INFO.  For arcs these attributes are:
COLUMN--ITEM_NAME----------WIDTH-----OUTPUT-----TYPE---#_DECIMALS
1-------FNODE#---------------4----------5---------B---------\
5-------TNODE#---------------4----------5---------B---------\
9-------LPOLY#---------------4----------5---------B---------\
13------RPOLY#---------------4----------5---------B---------\
17------LENGTH---------------8---------18---------F---------5
25------<cover>#-------------4----------5---------B---------\
29------<cover>-ID-----------4----------5---------B---------\
For polygons these attributes are:
COLUMN--ITEM_NAME----------WIDTH-----OUTPUT-----TYPE---#_DECIMALS
1-------AREA-----------------8---------18---------F---------5
9-------PERIMETER------------8---------18---------F---------5
17------<cover>#-------------4----------5---------B---------\
21------<cover>-ID-----------4----------5---------B---------\
The database consists of seven coverages (and one related scan; see Supplemental_Information) which contain the folowing data:
COVERAGE------------ENTITIES-----------DESCRIPTION
MOUNDSPG-GEO--------POLY/ARC-----------Geologic contacts and unit labels.
MOUNDSPG-FLT--------ARC----------------Geologic structures including faults, fold axes, and tension cracks.
MOUNDSPG-ATT--------POINT--------------Bedding attitudes.
MOUNDSPG-SYM--------ARC----------------Graphical representation of fault offset symbols (strike-slip arrows and bar-and-balls).
MOUNDSPG-GRV--------ARC----------------Graphical representation of gravity contours (includes contour values).
MOUNDSPG-DAT--------POINT/ARC----------U-series and thermoluminescence sample locations and graphical representation of symbols.
MOUNDSPG-TXT--------POINT/ARC----------Unit label points and leader lines.
The individual attributes for each coverage are described as follows:
MOUNDSPG-GEO (polygon attributes):
UNIT--Character attribute for rock unit from text (see table below);
SYMBOL--Integer attribute for polygon shade symbol from shadeset color524.shd (see table below).
MOUNDSPG-GEO (arc attributes):
CODE--Integer attribute for line type (see table below);
DESCRIPTION--Character attribute for line type description (see table below).
MOUNDSPG-FLT (arc attributes):
CODE--Integer attribute for line type (see table below);
DESCRIPTION--Character attribute for line type description (see table below).
MOUNDSPG-ATT (point attributes):
CODE--Integer attribute for line type (see table below);
DESCRIPTION--Character attribute for line type description (see table below);
AZIMUTH--Integer attribute for bedding attitude strike azimuth (clockwise from north);
DIP--Integer attribute for bedding attitude dip value.
MOUNDSPG-SYM (arc attributes):
CODE--Integer attribute for line type (see table below);
DESCRIPTION--Character attribute for line type description (see table below).
MOUNDSPG-GRV (arc attributes):
Only standard ARC attributes.
MOUNDSPG-DAT (arc attributes):
Only standard ARC attributes.
MOUNDSPG-DAT (point attributes):
SAMPLE-ID--Character attribute for U-series and thermoluminescence sample name.
MOUNDSPG-TXT (arc attributes):
Only standard ARC attributes.
MOUNDSPG-TXT (point attributes):
UNIT--Character attribute for rock unit from text (see table below).
UNIT/SYMBOL attribute values (see map text for explanation of lithologic units):
>QTa,109
>Qai,85
>Qau,108
>Qay,39
>Qayo,40
>Qayy,2
>Qbo,224
>Qbw,222
>Qby,216
>Qd,19
>Qfo,102
>Qfy,100
>Qpy,6
>Qscd,225
>Qse,224
>Qsu,233
>Qsy,221
CODE/DESCRIPTION attribute values:
>4 ,"definite contact in quaternary"
>5 ,"inferred contact in quaternary"
>10 ,"definite high angle fault"
>11 ,"inferred high angle fault"
>12 ,"concealed high angle fault"
>20 ,"definite fold axis"
>21 ,"inferred fold axis"
>22 ,"concealed fold axis"
>88 ,"tension crack"
>99 ,"map boundary"
>201 ,"bedding strike and dip"
>207 ,"bar and ball"
>210 ,"right-lateral strike-slip"

http://pubs.usgs.gov/mf/2002/mf-2339/mf-2339pam508.pdf