Surficial Geology of Iowa

This raster is a highly detailed (delineations made at the 1:15,840 scale) map of geologic materials at the surface, covering the entire state of Iowa. The map is based on the interpretations of the US Soil Survey, which regularly needs to assess the soil parent material in their mapping activities. The raster was generated from the USDA-NRCS gSSURGO spatial database (10 m resolution). The attributes were extracted from the NRCS official soil series descriptions (OSD), but at times some additional interpretation was needed based on typical soil profile properties and spatial relationships with better-defined soil series. Because of the common relationship between surficial geology and topography, digital elevation models or derived hillshades from the USGS would be complementary to this data set.

The zip file includes two ArcGIS layer files. One to provide a detailed legend and the other for a more generalized legend.

[wpdm_package id=’555′]

 

References

Miller, B.A. and C.L. Burras. 2015. Comparison of surficial geology maps based on soil survey and in depth geological survey. Soil Horizons 56(1). doi:10.2136/sh14-05-0005.

Soil Survey Staff. 2014. Official Soil Series Descriptions (OSD). United States Department of Agriculture, Natural Resources Conservation Service. https://soilseries.sc.egov.usda.gov/osdname.asp

Soil Survey Staff. 2014. Gridded Soil Survey Geographic (gSSURGO). United States Department of Agriculture, Natural Resources Conservation Service. http://datagateway.nrcs.usda.gov

Pre-settlement Water Regimes of Iowa Wetlands

IA_ps-wetlandsThis raster provides an estimate of the wetland water regimes in Iowa, prior to the implementation of drainage systems. These estimates are based on the spatial information in the USDA-NRCS gSSURGO database and soil series characteristics described in the official soil series descriptions (OSD). Soil series characteristics were matched as best as possible to the condition descriptions for the National Wetland Inventory’s defined water regimes. Soil properties and conditions described in the OSD are assumed to still be a reasonable estimate of the natural, undrained condition of the respective soils. This assumption is based on the fact that many soil properties that indicate past hydrologic conditions tend to persist over decades. Also, it is likely that some human memory of the landscape assisted in the description of soil series because determining past environmental conditions is important to understanding soil formation processes. It helps that much of the soil surveying occurred within 100-150 years after widespread use of drainage systems in Iowa. However, it should be noted that the more time between the pre-settlement conditions and when the soil was surveyed, the more likely the soil properties are to begin reflecting modern environmental conditions.

[wpdm_package id=’656′]

 

References

Miller, B.A., W.G. Crumpton, and A.G. van der Valk, 2009. Spatial distribution of historical wetland classes on the Des Moines Lobe, Iowa. Wetlands 29:1146-1152. doi: 10.1672/08-158.

Soil Survey Staff. 2014. Official Soil Series Descriptions (OSD). United States Department of Agriculture, Natural Resources Conservation Service. https://soilseries.sc.egov.usda.gov/osdname.asp

Soil Survey Staff. 2014. Gridded Soil Survey Geographic (gSSURGO). United States Department of Agriculture, Natural Resources Conservation Service. http://datagateway.nrcs.usda.gov

Physiography of the Des Moines Lobe

DML_physiographyThis 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. One is a surficial geology map of the Des Moines Lobe and surrounding areas. This raster was generated from the USDA-NRCS gSSURGO spatial database. The attributes were extracted from the NRCS official soil series descriptions (OSD), but at times some additional interpretation was needed based on typical soil profile properties and spatial relationships with better-defined soil series. The other data set delineates and divides the Des Moines Lobe by physiographic regions. These regions are based on major moraines denoting surfaces of notably different age as well as important changes in surficial geology and topography. Because of the close relationship between these maps and topography, digital elevation models from the USGS would be complementary to these data sets.

[wpdm_package id=’557′]

 

References

Miller, B.A., C.L. Burras, W.G. Crumpton. 2008. Using soil surveys to map Quaternary parent materials and landforms across the Des Moines Lobe of Iowa and Minnesota. Soil Survey Horizons 49(4):91-95. doi:10.2136/sh2008.4.0091

Soil Survey Staff. 2014. Official Soil Series Descriptions (OSD). United States Department of Agriculture, Natural Resources Conservation Service. https://soilseries.sc.egov.usda.gov/osdname.asp

Soil Survey Staff. 2014. Gridded Soil Survey Geographic (gSSURGO). United States Department of Agriculture, Natural Resources Conservation Service. http://datagateway.nrcs.usda.gov

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

[embeddoc url=”http://glsi.agron.iastate.edu/wp-content/uploads/2017/11/Using-Soil-Surveys-to-Map-Quaternary-Parent-Materials.pdf” download=”all” height=”380px”]

Wetland hydrologic class change from prior to European settlement to present on the Des Moines Lobe, Iowa

Miller, B.A., W.G. Crumpton, and A.G. van der Valk. 2012. Wetland hydrologic class change from prior to European settlement to present on the Des Moines Lobe, Iowa. Wetlands Ecology and Management 20(1):1-8. doi: 10.1007/s11273-011-9237-z. Continue reading “Wetland hydrologic class change from prior to European settlement to present on the Des Moines Lobe, Iowa”

Spatial distribution of historical wetland classes on the Des Moines Lobe, Iowa

Miller, B.A., W.G. Crumpton, and A.G. van der Valk. 2009. Spatial distribution of historical wetland classes on the Des Moines Lobe, Iowa. Wetlands 29(4):1146-1152. doi:10.1672/08-158.1. Continue reading “Spatial distribution of historical wetland classes on the Des Moines Lobe, Iowa”

Using soil surveys to map Quaternary parent materials and landforms

Miller, B.A., C.L. Burras, and W.G. Crumpton. 2008. Using soil surveys to map Quaternary parent materials and landforms across the Des Moines Lobe of Iowa and Minnesota. Soil Survey Horizons 49(4):91-95. Continue reading “Using soil surveys to map Quaternary parent materials and landforms”