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Bedrock Aquifers Several syntheses of extant information and information derived from directed research on bedrock aquifers have been prepared in the form of state-wide and regional reports for specific aquifers. Three major state-wide aquifers and one state-wide geologic unit are depicted on a series of maps, some of which have explanatory text. Listed below are available reports that cover portions of major and regional aquifers. The Maquoketa Formation (Upper Ordovician) in Iowa: GSB Miscellaneous Map Series 1 (MMS-1) MMS-1 is a summary of the regional variations in lithology, thickness, and distinguishing criteria of the Maquoketa Formation (Upper Ordovician) in Iowa. Six black-and-white map sheets (22" x 24") describe the extent, structural features, and composition of the Maquoketa Formation by thickness and lithofacies maps of the Elgin Limestone, Clermont Shale, Fort Atkinson Limestone, and Brainard Shale members; end-member plots; distribution, thickness, and topographic maps of the Maquoketa Formation; and accompanying text. Mississippian aquifer of Iowa: GSB Miscellaneous Map Series 3 (MMS-3) The purpose of MMS-3 is to present information on the occurrence, movement, availability, use, and chemical quality of water from the Mississippian aquifer in Iowa. The geohydrologic information is presented on three color map sheets (34"x44") - geology, hydrology, and chemical quality - including accompanying text, stratigraphic column, and cross sections. Jordan aquifer of Iowa: GSB Miscellaneous Map Series 6 (MMS-6) The purpose of MMS-6 is to (1) define and describe the spatial relations and physical characteristics of the Jordan aquifer, (2) present information on the occurrence, availability, use, and chemical quality of water in the aquifer, and (3) define and delineate changes in the potentiometric surface of the aquifer. The geohydrologic information is presented on three color map sheets (34"x44") - geology, hydrology, and chemical quality - including accompanying text, stratigraphic column, and cross section. Silurian-Devonian aquifer of Iowa The purpose of GSB Miscellaneous Map Series 10 (MMS-10) is to present information on the occurrence, movement, availability, use, and quality of water in the Silurian-Devonian aquifer of Iowa. Four color map sheets (34" x 44") are available: Sheet 1 provides a definition of the aquifer; its physical characteristics, including a discussion of karst features; a contour map of the surface of the aquifer; and cross sections; Sheet 2 details the distribution and thickness of the Devonian and Silurian rocks, as well as overlying and underlying confining beds, and the base of the aquifer; Sheet 3 defines the aquifer's hydrologic characteristics, the potentionmetric surface, water levels, a schematic flow system, data on withdrawals, yields, well-development techniques, fracture systems, and a map of known sinkholes; Sheet 4 presents a discussion of water quality in the aquifer, properties and constituents of the water, selected mineral analyses, maps showing concentrations of significant mineral constituents, water temperatures, and an overburden-thickness map outlining areas potentially susceptible to nitrate, bacteria, and other forms of contamination from surface activities. Hydrology of carbonate aquifers in southwestern Linn County and adjacent parts of Benton, Iowa, and Johnson counties, Iowa: GSB Water-Supply Bulletin 15 (Abstract) Floyd and Mitchell Counties I. Hydrogeologic observations from multiple core holes and piezometers in the Devonian-carbonate aquifers in Floyd and Mitchell counties, Iowa; II. Stratigraphic framework for the Devonian aquifers in Floyd-Mitchell counties, Iowa: GSB Open File Report 85-2 (Abstract) I. Groundwater Quality and Hydrogeology of Devonian-Carbonate Aquifers in Floyd and Mitchell Counties, Iowa ; II. Devonian Stratigraphy of North-Central Iowa: GSB Open File Report 84-2 (Abstract) Dakota Formation Hydrogeology and stratigraphy of the Dakota Formation in northwest Iowa: GSB Water-Supply Bulletin 13 (Abstract) Hydrology of the alluvial, buried channel, basal Pleistocene and Dakota aquifers in west-central Iowa: USGS Water Resources Investigation Report 85-4239 Availability and Quality of Water from the Alluvial, Glacial-Drift, and Dakota Aquifers and Water Use in Southwest Iowa: USGS Water Resources Investigation Report 91-4156 Availability and quality of water from the Dakota Aquifer in Northwest Iowa: USGS Water-Supply Paper 2215