• Surficial Geology of Iowa

    Raster of the surficial geology of Iowa based on the parent material interpretations of the US Soil Survey. The map is built from delineations made at a 1:15,840 scale, then converted to a 10 m resolution grid. This data set is based on the spatial information in the USDA-NRCS gSSURGO database and soil series characteristics described in the official soil series descriptions (OSD).

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  • Physiography of the Des Moines Lobe

    This GIS package contains a pair of spatial data sets that have been generated for the purpose of studying the physiography of the Des Moines Lobe landform region. Includes a 10 m resolution grid interpreting the surficial geology from gSSURGO. Also includes a polygon shapefile that delineates the Des Moines Lobe into physiographic regions based on that surficial geology map and relief.

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  • Filtering Particle Size Distribution of Mixed Sediments (2012 INQUA Loess Conference)

    Most loess has unimodal textural curves, with a peak in the silt fraction. However, in thin loess areas, where loess overlies coarse-textured sediment, it often has a bimodal textural curve, due to pedoturbation. We present a method that can tease out these two textural signatures and thus, estimate the original particle size distribution of the loess. In this method the coarser sediment portion of such a “mixed” particle size distribution curve is removed, or “filtered out.” The end result is a curve (and data) that better reflect the original textural characteristics of the loess.

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  • Using Soil Surveys to Delineate Quaternary Parent Materials and Landforms (2010 Binghamton Geomorphology Symposium)

    We sought to create the best possible Quaternary geology map of the Des Moines Lobe solely using readily available National Cooperative Soil Survey (NCSS) data. We then sought to test whether that map is comparable to Quaternary geology maps previously published by geologists. Categorization of soil map units with respect to geologic unit successfully created a detailed Quaternary geologic map for the Des Moines Lobe, showing strong agreement with the existing Quaternary geologic maps while adding a user-controlled level of scale.

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  • Thin, pedoturbated, and locally sourced loess in the western Upper Peninsula of Michigan

    County soil surveys document thin loess deposits across large tracts of Michigan’s western Upper Peninsula (UP), which we informally call the Peshekee loess. Our study is the first to examine the distribution, thickness and textural characteristics of these loess deposits, and speculate as to their origins. We introduce and describe a method by which the mixed sand data are removed, or “filtered out,” of the original particle size data, to better reflect the original textural characteristics of the loess.

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  • Using soil surveys to map Quaternary parent materials and landforms

    The integration of soil survey maps with Geographic Information Systems (GIS) allows for an almost infinite level of collaboration across disciplines that use information related to soil databases. This study created a Quaternary geologic map by categorizing soil descriptions into a geologic context and joining the attributes with the Soil Survey Geographic (SSURGO) database in ArcGIS®. The resulting map communicates many of the spatial intricacies of the Des Moines Lobe landform with 15 map units based on geologic units.

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