U.S. Geological Survey (USGS) - Great Lakes Geologic Mapping Coalition
||Current knowledge of the provenance and chronology (relative and absolute) of deposits of the different ice lobes in the interlobate region of northern Indiana is fragmented and based mainly on individual studies. These studies were conducted over a large area and generally lack a unifying synthesis. Additionally, the identification and characterization of water resources associated with outwash deposits in the interlobate region is of broad interest to many stakeholders.
||The main objective of this project is to map outwash and morphosequences of outwash and moraines and determine the chronology of these deposits related to the Lake Michigan, Saginaw, and Huron-Erie lobes in the St. Joseph and Kankakee drainage basins in northern Indiana using a GIS framework. Another primary goal is to develop an absolute chronology for morphosequences and ice margins of the three lobes by using optically stimulated luminescence (OSL) dating of fan/outwash sediments tied directly to ice margin positions. Combined with a relative chronology identified by cross-cutting relationships of landforms and stratigraphy, these OSL ages can provide a framework for timing of fluctuations of the Lake Michigan, Saginaw, and Huron-Erie lobes.
||Our approach involves integrating soil texture and topography using SSURGO and LIDAR data to create a soil morphology map. Soil textures will be interpreted based on their parent material and mode of genesis (e.g., till, outwash, eolian, alluvium). The project will integrate detailed and reconnaissance glacial geologic maps (e.g., published and unpublished 7.5-minute maps and county maps) constructed through STATEMAP, FEDMAP, and IGS reports into a single GIS coverage in northern Indiana and southern Michigan. With the availability of new high-resolution LiDAR data, a main point of emphasis will be identifying morphosequences and relating drainage routes of meltwater to moraines as well as identifying cross-cutting relationships between landforms which aid in the reconstruction of a relative chronology.
||Products for this project include: 1) map (1:100,000-scale) of outwash and morphosequences of outwash and moraines in the St. Joseph and Kankakee drainage basins, 2) report of results and interpretation for chronological analyses. These will be Indiana Geological Survey Open-File Reports.
||Integration of geologic mapping in northern Indiana completed over the past 25 years into a single map at 1:100,000-scale. Mapping will aid in identification and characterization of water resources in the map area.