DATABASE STRUCTURE--The database structure of the map consists of
one coverage, SURF_DEP, with the following INFO attribute items.
>AREA
>PERIMETER
>SURF_DEP #
>SURF_DEP-ID
>DEPOSIT_TYPE
>VALUE
The coverage SURF_DEP contains all contact lines and label points for each
polygon.  The SURF_DEP.PAT INFO file has attribute fields for INFO ITEMS
DEPOSIT_TYPE and VALUE.  DEPOSIT_TYPE corresponds to a unique symbol that
identifies specific surficial deposit types.  Some units have a mixed
deposit type such as b/t where both bog and terrace deposits represent a
polygon.  VALUE is a unique numeric identifier that represents each
general class of surficial deposits.  Note that where a mapped unit has
multiple generations of terraces that are represented by t1, t2, and t3 in
the DEPOSIT_TYPE field, these have the same numeric VALUE.  The VALUE
attribute also corresponds to the ArcInfo colornames.shd symbolset number
used for color shading.  The following detailed overview discusses all of
the non-common attributes included in the SURF_DEP coverage:
The ITEM DEPOSIT_TYPE is described as follows:
>H = Human-related deposits and structures
>Fp = floodplain deposits
>Rfp = reworked floodplain deposits
>T = terrace deposits undifferentiated based on comparative relative ages
>t1,t2,t3,t4 = terrace deposits, with higher number corresponding to older terraces
>rt = reworked terrace
>rt1 = reworked terrace (relative order of formation 1)
>rt2 = reworked terrace (relative order of formation 2)
>vd = valley deposits
>rvd = reworked valley deposits
>ovd = old valley deposits
>ox = oxbow deposits, abandoned channels
>f = fan deposits undifferentiated based on comparative relative ages
>f1,f2,f3 = fan deposits, with higher number corresponding to older fans
>rf = reworked fan
>b = bog deposits
>ib = iron bog deposits
>c = colluvial deposits
>rc = reworked colluvium
>dc = debris cone deposits
>ta = talus deposits
>ls = landslide deposits
>ls1,ls2 = landslide deposits, with higher number corresponding to older landslides
>m = glacial till
>ma,ms = Animas City (ma) and Spring Creek (ms) glacial till deposits
>m? = possible glacial till
>rm = reworked glacial till
>rm? = possible reworked glacial till
>c/ovd = mixed colluvial and old valley deposits
>c/m = mixed colluvial and glacial till deposits
>m/c = mixed glacial till and colluvial deposits
>f/m = mixed fan and glacial till deposits
>ls/m = mixed landslide and glacial till deposits
>t/m = mixed terrace and glacial till deposits
>f/t = mixed fan and terrace deposits
>t/b = mixed terrace and bog deposits
>B/c = mixed bedrock and colluvial deposits
>B/fp = mixed bedrock and floodplain deposits
>B/ls = mixed bedrock and landslide deposits
>B/m = mixed bedrock and glacial till deposits
>td = travertine deposits
>B = bedrock
>rB = reworked bedrock
>w = water
>L =lake
The INFO file item VALUE is populated with a numeric value that
corresponds to the ArcInfo colornames.shd shadeset file and is also a
unique value that represents each general class of surficial deposit
types.  Note that a deposit type with multiple generations of deposits
such as t1, t2, and t3 have the same numeric value.  Also, when there are
mixed units, the value recorded in the VALUE field represents the first
deposit type reported in the mixed deposit, that is, the value for t in
the case of the unit t/b.  The DEPOSIT_TYPES and corresponding numeric
VALUE attributes are as follows:
>H = 4
>fp = 3
>t = 6
>vd = 10
>rvd = 10
>ovd = 12
>ox = 86
>f = 13
>rf = 13
>f1 = 13
>f2 = 13
>f3 = 13
>f/m = 13
>b = 8
>ib = 14
>c = 82
>rc = 82
>dc = 18
>ta = 80
>ls = 17
>ls1 = 17
>ls2 = 17
>m = 81
>ma = 81
>ms = 81
>m? = 81
>rm = 81
>rm? = 81
>c/ovd = 82
>c/m = 82
>m/c = 81
>f/m = 13
>ls/m = 17
>t/m = 6
>f/t = 13
>t/b = 6
>B/c = 25
>B/fp = 25
>B/ls = 25
>B/m = 25
>td = 109
>B = 25
>rB = 25
>w = 21
>L = 21

http://pubs.usgs.gov/dds/dds-071/dds71_text_ver.pdf

Surficial geologic units (polygons)