MINERALOGICAL EVIDENCE FOR EOLIAN CONTRIBUTION TO SOILS OF LATE QUATERNARY MORAINES, WIND RIVER MOUNTAINS, WYOMING, USA

Volcanic heavy minerals are found in the A and B horizons of soils on moraines of the western Wind River Mountains of Wyoming. Volcanic minerals do not occur in the underlying moraine sediments derived from plutonic and metamorphic bedrock. Sources of the volcanics are the sedimentary rocks of the Green River Basin. The presence of volcanic minerals in the Green River Basin and their patterns of distribution in the moraine soils indicate eolian sedimentation is an important factor of soil genesis in this region. Moraines affected by eolian sediments include the Pinedale and Temple Lake/Indian Basin type localities. The presence of eolian sediments in both Pinedale and Holocene deposits suggests eolian addition is not simply a late glacial phenomenon, but continues throughout postglacial time. Relations between eolian sediments and soil development must be accounted for when comparing soil development on moraine chronosequences in this and possibly all alpine regions of western North America.