GN022

Nestled below the flat, placid farmlands of northwestern Indiana lies one of Indiana’s strangest geologic features. An elliptical area (about 7 miles across), near Kentland in New-ton County, contains highly deformed rocks that bespeak of incredible forces so great that layers of rock normally in a horizontal position 1,800 feet below the surface are folded and fractured and are now exposed at the surface in nearly vertical positions.

Since the 1880s, geologists have known about the Kentland structure. Many attempts have been made to explain its origin. One theory proposes that a meteorite hit the Earth and caused a large crater like those on the Moon; another is that trapped gases from deeply buried volcanism caused the faulting. Geologic evidence, such as shatter cones and minerals formed under very high pressure, imply an origin by meteorite impact.

Kentland Dome: Geologic Enigma

Shatter cone

Dip of rocks indicatedby yellow lines

Nearlyvertical rocks

GEONotes

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