Abstract
ABSTRACT Pleistocene periglacial eolian sediments are widespread in the Nushagak, Holitna, and Upper Kuskokwim lowlands of southwestern Alaska. These sediments comprise mainly sand-sheet deposits and sand-loess intergrades, with subordinate sand-dune deposits and loess. Sand-sheet deposits range from 1) sharply defined, parallel, low-angle laminae formed by migrating wind ripples to 2) irregular subhorizontal strata which reflect migration of poorly segregated wind ripples, accumulation on a sparsely vegetated surface, adhesion on a quasi-planar bed, and/or niveo-eolian deposition. Sand-loess intergrades represent alternating bed-load and suspension deposition related mainly to the stochastic and seasonal variability of former wind systems. The dominance of sand-sheet deposits over deposits of well-formed dunes in the Pleistocene eolian record of southwestern Alaska reflects the limited availability of loose, dry sand in this former periglacial environment. Immobilization of sand after deposition as low-relief sheets resulted from a seasonally variable combination of ice cementation, sparse vegetation, high water tables, and snow cover.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.