PERMFILE45298

• Permit No: C1996083
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Volume III Exhibit 12 Geologic Symbols
• Media Type: D
• Archive: No

• Glacial Deoosits
EXPLANATION OF MAP UNITS
Qgdy Younger glacial drift (late Pleistocene):
unsorted to poorly sorted, subangular,
unconsolidated, pebble to boulder-size
detritus in a fine-grained matrix. These
deposits generally form a hummocky topography
above 7500 ft., may be modified by mass-
wasting processes, and are potentially
unstable especially when underlain by the
Wasatch Formation.
Qgdm Middle glacial drift (middle Pleistocene):
unsorted, subangular, poorly consolidated,
bouldery detritus. These deposits usually
have a greater amount of weathered igneous-
rock fragments and form a more subdued
topography than the younger glacial deposits.
Qgdo Older glacial drift (middle Pleistocenel:
unsorted, subangular, poorly consolidated,
pebble to boulder-size detritus. These
deposits, exposed in the northern part of the
Bowie Quadrangle, are separated from Qgdm by
a partially eroded paleosol.
• Alluvial Deoosits
Qal Flood-plain alluvium (Holocene): mixtures of
silt, sand, pebbles, and cobbles that have
been recently deposited and/or reworked by
fluvial processes. The alluvium forms the
physiographic flood plains of the modern
drainage system and is a potential source of
sand, gravel, and crushed-rock aggregate.
Qat Stream-terrace alluvium (HOlocenel: poorly
sorted deposits that are similar to Qal in
composition and form small terraces near the
present drainage. Generally the deposits are
less than 10 ft. (3m) above modern streams.

P6PIIIS •e-LIGlIOP EXH-12 - 9 -