The NSS Bulletin - ISSN 1090-6924
Volume 38 Number 3: 59-67 - July 1976
A publication of the National Speleological Society

Doline Densities in Northern Iowa
Robert C. Palmquist, Gary A. Madenford and J. Nicholas Van Driel

Abstract

Variation of doline density in the karsted areas of three counties in Iowa indicates that doline density is controlled by carbonate distribution, thickness of clastic overburden, and bedrock topography. Dolines are limited to areas with a thickness of till and loess less than 25 ft (7.6 m) and are common along the drainageways of bedrock uplands. Average doline densities for the karsted area within a county range from 45 per square mile (17.3/km2) in Nebraskan drift to 4.6 per square mile (1.8/km2) in late Wisconsinan drift. Mean doline density (D) increases with time (T) according to D = 18.8 log Y - 72.3 in areas of thin drift. Dolines show preferential development along low order drainageways where overburden is thin and ground water recharge is presumed to be large. Data was obtained from S.C.S. county soil reports.

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