Indiana Dunes National Park: Geologic resources inventory report
Thornberry-Ehrlich TL. 2020. Indiana Dunes National Park: Geologic resources inventory report. Natural Resource Report. NPS/NRSS/GRD/NRR—2020/2196. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/nrr-2279904
This report synthesizes discussions from a scoping meeting held in 2010 and a follow-up conference call in 2018 (see Appendix A). Chapters of this report discuss the geologic setting, distinctive geologic features and processes within Indiana Dunes National Park, highlight geologic issues facing resource managers, describe the geologic history leading to the present-day landscape, and provide information about the previously completed GRI map data. A poster illustrates these data. Vast piles of wind-whipped sand rise dramatically from the shores of Lake Michigan along the 24 km (15 mi) of shoreline contained in Indiana Dunes National Park. For nearly 2.6 million years, the Laurentide ice sheet that originated in the Arctic advanced and retreated multiple times over the Great Lakes region in response to climatic variability. The movements of ice, along with the sediment and meltwater they produced, blocked and rerouted river systems, scoured the Great Lakes basins, and left a complex glacial geologic record on the local landscape. During the last glacial episode and following each glacial advance, an ancestral version of the modern Lake Michigan formed between the glacier’s terminal moraine and the ice margin. Relic shorelines exist as a geologic record of changes in Lake Michigan through time and are brilliantly preserved at the park, which has provided a natural scientific laboratory for more than 100 years. Earth surface processes continue to modify and affect the Indiana Dunes landscape. These include the famous dunes but also meandering streams, bogs, marshes, pannes (a type of wetland), beaches, and hardwood forests. Geology and geologic processes affect nearly every facet of the natural environment of the park as well as its long and rich human history. This report is supported by one GRI–compiled map of the surficial and glacial geology of Indiana Dunes National Park. The compiled map coverage (4-letter code: indu) encompasses vast portions of Lake and Porter Counties, including the entirety of the park lands. The surficial and glacial map coverage differentiates the units deposited by the Pleistocene glaciers from those more recent paralic (of and pertaining to the coast) units being reworked and accumulating on the modern landscape by Earth surface processes. The map data poster (see “GRI Map Poster”) is the most important figure of this GRI report showing the GRI GIS data draped over aerial imagery of the park. Individual surficial and glacial units are included in the poster’s legend. This report outlines and describes the park’s geologic features, processes, and resource management, including...
- Type
- Published Report
- Authors
- Thornberry-Ehrlich, Trista
- Date of Issue
- 2020-11
- Publisher
- National Park Service
- DOI
- 10.36967/nrr-2279904
- Units
- GLKN , GRD , GRI , INDU , MWRO , NRSS
- Keywords
- and Earthquakes, Coastal/Lacustrine Features and Processes, Disturbed Lands, Eolian Features and Processes, Fluvial Features and Processes, Geologic Features, Geologic Hazards: Slope Movements, Geologic History, Geologic Map, Geologic Processes, Geologic Resource Management, Geologic Resource Management Issues, Geologic Resources Division, Geologic Resources Inventory, Glacial Features and Processes, GRD, GRI, Indiana, Indiana Dunes National Park, INDU, National Park Service, NPS, Paleontological Resources, Resource Management, Sand Collapses, Shoreline Erosion, Sources for Geologic Resource Management Guidance
- Subjects
- Ecological Framework: Geology and Soils | Geomorphology | Windblown Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Glacial Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Hillslope Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Coastal/Oceanographic Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Stream/River Channel Characteristics , Ecological Framework: Geology and Soils | Geomorphology | Lake Features and Processes , Ecological Framework: Geology and Soils | Subsurface Geologic Processes | Seismic Activity , Ecological Framework: Geology and Soils | Soil Quality | Soil Function and Dynamics , Ecological Framework: Geology and Soils | Paleontology | Paleontology