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Please use this identifier to cite or link to this item: http://hdl.handle.net/11299/57303

Title: Geologic Map Series 1. Bedrock Geology of Duluth and Vicinity St. Louis County, Minnesota
Authors: Taylor, Richard B.
Keywords: geology
Minnesota Geological Survey
northeastern Minnesota
Issue Date: 1963
Publisher: Minnesota Geological Survey
Series/Report no.: Geologic Map Series
Abstract: Duluth, Minnesota, is on the northwest limb of the Lake Superior syncline, a northeast-trending structure of Precambrian age. The north- west limb of the syncline dips 10-20 degrees S.E. toward Lake Superior and is dominated by the Duluth Gabbro Complex, a huge sill-like mass with crescentic outcrop that extends almost 150 miles from Duluth to near Hovland. At Duluth the gabbro complex lies on the Thomson Formation, and apparently was intruded along the surface of unconformity below the Keweenawan rocks. The gabbro complex was formed by multiple intrusion, and consists of an older anorthositic gabbro and a younger layered gabbro and related intrusions. Keweenawan flows above the gabbro mass are cut by diabase sills. The basalt flows at one locality currently are being quarried as a source of crushed rock for concrete aggregate.
Description: Text 12 p., 1 map plate. Scale 1:24,000.
URI: http://purl.umn.edu/57303
Appears in Collections:Geologic Map Series

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MGS_GM_1.pdfText299.54 kBPDFView/Open
umn23362.pdfGM-1 Map9.19 MBPDFView/Open

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