IGB

Connexion

(Article of periodic en Anglais - 1982)

Document title

Sedimentology and palynology of Middle Wisconsinan deposits in the Pecatonica River valley, Wisconsin and Illinois

Authors(s) and Affiliation(s)

WHITTECAR G. R. ; DAVIS A. M. ;

Abstract

The bedrock valley of the Pecatonica River north of Freeport, Illinois, contains a thick valley-fill complex of alluvium and drift. Within the valley, loess-capped benches surround hills of silty Illinoian drift. Beneath these benches lie thick deposits of poorly sorted stony silt interbedded with thin lenses of silt, sand, and organic-rich loam. Channel deposits and peat cap the diamicton in places. We interpret the stony silts as solifluction debris shed from silty slopes within the valley-fill during the Early or Middle Wisconsinan (Altonian). Top and bottom radiocarbon dates from a 2.5-m section of peat overlying the diamicton are 26,820200 and 40,5001700 yr B.P., respectively. Together pollen and sediment data indicate that during the Middle Wisconsinan, Pecatonica hillslopes progressed through a sequence of instability-stability-instability related to climatic fluctuations.

Source

Article of periodic

published at : Quaternary research New York

Editor :

Millesime : 1982, vol. 17, no2 [pp. 228-240]

Bibliographic references : 46 réf.

Language

Anglais

Refdoc record number (ud4) : 12453726 : Permanent link - XML version
Powered by Pxxo