Laserfiche WebLink
Qta Talus/Scree deoosits (Holocene to late <br />• Pleistocenel: angular, unsorted, pebble to <br />boulder-size rock fragments that mantle <br />mountain slopes or accumulate at the base of <br />a barren-rock mass. The deposits usually <br />form steep, concave slopes and include talus <br />cones and lobate or tongue-shaped rock <br />glaciers. Mass-wasting processes are <br />currently active in the formation of these <br />deposits. <br />Qcw Colluvial-wedge deposits (Holocene to late <br />Pleistocenel: unconsolidated, heterogeneous <br />soil material and rock fragments found near <br />the base of a slope. Formed by gravity- <br />dominated processes, the deposits may be <br />subject to continued mass-wasting. <br />Bedrock Units <br />Tb Basaltic intrusive rocks (Miocenel: dark gray <br />to black phorphyritic intrusive rocks that <br />contain fine-grained pheocrysts of olivine <br />and pyroxene. <br />Tip Porahritic intrusive rocks (Miocene and <br />Oligocenel: light-gray porphyritic intrusive <br />• rocks that vary in composition from quartz <br />monzonite to granodiorite. <br />Tqr Green River Formation (Eocenel: probably <br />calcareous siltstone and shaley marlstone <br />(Hail, 1972). The formation, obscured by <br />surficial material, is subject to mass- <br />wasting processes. <br />Tow Ohio Creek Wasatch Formations (Eocene and <br />Paleocenel: vari-colored (usually red, <br />purple, green, yellow, and gray) mudstone and <br />siltstone with interbedded medium-gray, <br />lenticular sandstone and conglomeratic <br />sandstone. The formation generally is <br />obscured by surficial deposits, is prone to <br />mass-wasting, and is potentially unstable. <br />Kmv Mesaverde Formation (late Cretaceousl: brown, <br />gray, and light gray to white sandstone <br />interbedded with dark gray shale. <br />Commercially important coal beds occur in the <br />lower part of the formation. The formation <br />forms very steep slopes which are subject to <br />rockfalls and other mass-wasting processes. <br />• In many places these steep slopes are stable. <br />P6PMIS 11PPLIG7IOP EXH-12 - 13 - <br />