Keweenaw Fault

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Geology of the Lake Superior Region

The Keweenaw Fault is a reverse fault that bisects the Keweenaw Peninsula of the Upper Peninsula of Michigan.[1] The fault is the boundary between the Midcontinent Rift System and adjacent Precambrian terrain. The peninsula, itself, is the southeastern side of a large syncline beneath Lake Superior. The northwestern side forms Isle Royale.[2]

The fault is more than 100 miles (160 kilometers) long and traces a northwesterly path.[3] The fault is most likely younger than the Jacobsville Formation and the Devonian Period.[4]

An seismic event in 1906 claimed to be an earthquake has been attributed to a rock burst, as the area has been significantly mined.[5]

The Natural Wall[edit]

One significant feature along the Keweenaw Fault is known as the Natural Wall. The Wall is a near-vertical slope of sandstone at a maximum inclination of 85°.[6]

References[edit]

  1. ^ Brandes, Paul. "Geology of the Keweenaw Peninsula, Michigan". mindat.org. Retrieved March 4, 2012. 
  2. ^ Huber, N. King (1975). "The Geologic Story of Isle Royal National Park". United States Geological Survey. Retrieved February 2, 2008. 
  3. ^ Hamblin, W.M. Kenneth (1958) (PDF). The Cambrian Sandstones of Northern Michigan (Report). State of Michigan Department of Conservation. p. 47. http://www.michigan.gov/documents/deq/PU_51_C_308647_7.pdf. Retrieved February 16, 2012.
  4. ^ Hamblin, W.M. Kenneth (1958) (PDF). The Cambrian Sandstones of Northern Michigan (Report). State of Michigan Department of Conservation. p. 48. http://www.michigan.gov/documents/deq/PU_51_C_308647_7.pdf. Retrieved February 16, 2012.
  5. ^ McLaren, Noël (August 30, 2011). "Could the Keweenaw Fault become active?". Upper Michigan's Source. Retrieved March 4, 2012. 
  6. ^ Irving, E. D.; Chamberlin, T. C. "Observations on the Junction Between the Eastern Sandstone and the Keweenwaw Series on Kweweenaw Point, Lake Superior". State of Michigan. Retrieved July 21, 2011.