Loess Identification in Soils of Southeastern Pennsylvania
1976
Carey, J. B. | Cunningham, R. L. | Williams, E. G.
A silty mantle generally 1 m thick in southeastern Pennsylvania was thought to be loess. Sorting coefficients determined from particle size analysis of horizons from 20 profiles indicate the silty materials are well sorted. Bartlett's (X²) test for homogeneity of variances of the percent clay-free silt among 21 profiles of Duncannon soils shows a homogeneous population having a mean variance of 3.9. A mean variance of 2.3 was determined for Fayette, a known Midwest loess soil. Transects through the area of thickest loess show percent very fine sand decreasing from south to north. The mean percent very fine sand of the profiles in each transect shows a decrease from east to west. The physical properties, sorting coefficients, and homogeneity indicate the silty mantle is loess. The mantle's geographic location, gradation in thickness, and very fine sand content indicate that the Coastal Plain and the adjacent rivers are probable source areas for the loess.
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