Geology of Minnesota

The geology of Minnesota is the study of the rock, minerals, and soils of the U.S. state of Minnesota, including their formation, development, distribution, and condition.

The state's geologic history can be divided into three periods. The first period was a lengthy period of geologic instability from the origin of the planet until roughly 1,100 million years ago. During this time, the state's Precambrian bedrock was formed by volcanism and the deposition of sedimentary rock and then modified by processes such as faulting, folding and erosion. In the second period, many layers of sedimentary rock were formed by deposition and lithification of successive layers of sediment from runoff and repeated incursions of the sea. In the third and most recent period starting about 1.8 million years ago, glaciation eroded previous rock formations and deposited deep layers of glacial till over most of the state, and created the beds and valleys of modern lakes and rivers.

Minnesota’s geologic resources have been the historical foundation of the state's economy. Precambrian bedrock has been mined for metallic minerals, including iron ore, on which the economy of Northeast Minnesota was built. Archaen granites and gneisses, and later limestones and sandstones, are quarried for structural stone and monuments. Glacial deposits are mined for aggregates, glacial till and lacustrine deposits formed the parent soil for the state's farmlands, and glacial lakes are the backbone of Minnesota's tourist industry. These economic assets have in turn dictated the state's history and settlement patterns, and the trade and supply routes along the waterways, valleys and plains have become the state's transportation corridors.

Geological history

Formation of Precambrian bedrock

Minnesota contains some of the oldest rocks on Earth, granitic gneisses that formed some 3,600 mya (million years ago) — roughly 80% the age of the planet. [Ojakangas and Matsch, "Minnesota's Geology", p. 23.] About 2,700 mya, the first volcanic rocks that would later form the U.S. state of Minnesota began to rise up out of an ancient ocean, forming the Superior craton. [Ojakangas and Matsch, "Minnesota's Geology", pp. 25-32.] This craton later assembled into the Canadian shield, which became part of the North American craton. Much of the underlying gneiss rock of today's state had already formed nearly a billion years earlier, but lay underneath the sea. [] 90%, or some three million acres (12,000 km²), have been drained for agriculture in the Minnesota River basin.] Along the eastern edge of the region are the Dalles of the St. Croix River, a deep gorge cut by runoff from Glacial Lake Duluth into ancient bedrock. cite web
last = Black
first = Robert F.
authorlink =
coauthors =
title = Chapter 10: St. Croix Dalles Interstate Park
work = Geology of Ice Age National Scientific Reserve of Wisconsin, NPS Scientific Monograph No. 2
publisher = National Park Service
date = 2005
url = http://www.cr.nps.gov/history/online_books/science/2/chap10.htm
format =
doi =
accessdate = 2007-06-30 ] Interstate Park here contains the southernmost surface exposure of the Precabrian lava flows of the Midcontinent Rift, providing a glimpse of Minnesota's volcanic past.cite web
last = Jol
first = Harry M.
authorlink =
coauthors =
title = Interstate State Park, A Brief Geologic History
work =
publisher = University of Wisconsin at Eau Claire
date = 2006
url = http://www.uwec.edu/jolhm/Interstate2006/history.htm
format =
doi =
accessdate = 2007-06-30 ]

References

Notes

ources

Books, journals and monographs (including web-republished print media)

*cite web
last = Chandler
first = Val W
authorlink =
coauthors =
title = A Geophysical Investigation of the Ely Greenstone Belt in the Soudan Area, 4-5
work = Open File Report 05-1
publisher = Minnesota Geological Survey
date = 2005-08-03
url = http://webusers.physics.umn.edu/~marshak/dusel_b_appendices/IUS-DUSEL_Appendix_B4.pdf
format =
doi =
accessdate = 2007-06-30
* cite book
last = Heinselman
first = Miron
authorlink =
coauthors =
title = The Boundary Waters Canoe Area Wilderness Ecosystem
publisher = University of Minnesota Press
date = 1996
location = Minneapolis
pages =
url =
doi =
id = ISBN 0-8166-2804-1
*cite journal
last = Heinselman
first = Miron L.
authorlink =
coauthors =
title = Forest Sites, Bog Processes, and Peatland Types in the Glacial Lake Agassiz Region, Minnesota
journal = Ecological Monographs
volume = 33
issue = 4
pages = 327–374
publisher = Ecological Society of America
date = Autumn 1963
url = http://www.peatnet.siu.edu/Assets/Heinselman%201963.pdf
doi = 10.2307/1950750
id =
accessdate = 2007-06-30
*cite web
last = Lusardi
first = B.A.
authorlink =
coauthors =
title = Quaternary Glacial Geology
work = Minnesota at a Glance
publisher = Minnesota Geological Survey, University of Minnesota
date = 1997
url = http://www.winona.edu/geology/MRW/MNglance/Mn_Quaternary.pdf
format =
doi =
accessdate = 2007-06-30
*cite journal
last = Morey
first = G. B.
authorlink =
coauthors =
title = High-grade iron ore deposits of the Mesabi Range, Minnesota; product of a continental-scale Proterozoic ground-water flow system
journal = Economic Geology and the Bulletin of the Society of Economic Geologists
volume = 94
issue = 1
pages = 133–42
publisher = Society of Economic Geologists
date = February 1999
url = http://www.geoscienceworld.org/cgi/georef/1999036918 (Abstract)
doi =
id =
accessdate = 2007-06-30
* cite book
last = Nute
first =Grace Lee
authorlink =
coauthors =
title = Rainy River Country
publisher = Minnesota Historical Society
date = 1950
location = Saint Paul
pages =
url =
doi =
id =
isbn =
* Citation
last = Ojakangas
first = Richard W.
author-link =
last2 = Matsch
first2 = Charles L
author2-link =
title = Minnesota's Geology
place= Minneapolis
publisher = University of Minnesota Press
year = 1982
location =
volume =
edition =
url =
doi =
id = ISBN 0-8166-0953-5.
* Citation
last = Sansome
first = Constance Jefferson
authorlink =
coauthors =
title = Minnesota Underfoot: A Field Guide to the State's Outstanding Geologic Features
publisher = Voyageur Press
date = 1983
location = Stillwater, MN
pages =
url =
doi =
id = ISBN 0-8965-8036-9.
*cite journal
last = Van Schmus
first = W. R.
authorlink =
coauthors = Hinze, W. J.
title = The Midcontinent Rift System
journal = Annual Review of Earth and Planetary Sciences
volume = 13
issue =
pages = 348
publisher = Annual Reviews
date = May 1985
url = https://kuscholarworks.ku.edu/dspace/bitstream/1808/104/1/fac6cit13.pdf
doi = 10.1146/annurev.ea.13.050185.002021
id =
accessdate = 2007-06-30
* cite journal
last = Upham
first = Warren
authorlink =
coauthors =
title = The Glacial Lake Agassiz
journal = Monographs of the United States Geological Survey
volume = XXV
issue =
pages =
publisher = United States Geological Survey/University of North Dakota
date = 1896/2002
url = http://www.lib.ndsu.nodak.edu/govdocs/text/lakeagassiz/index.html
doi =
id =
accessdate = 2007-06-30
* Citation
last = Waters
first = Thomas F.
author-link =
last2 =
first2 =
author2-link =
title = The Streams and Rivers of Minnesota
place= Minneapolis
publisher = University of Minnesota Press
year = 1977
location =
volume =
edition =
url =
doi =
id = ISBN 0-8166-0821-0.

Websites

* cite web
last = Black
first = Robert F.
title = Chapter 10: St. Croix Dalles Interstate Park
work = Geology of Ice Age National Scientific Reserve of Wisconsin, NPS Scientific Monograph No. 2
publisher = National Park Service
date = 2005
url = http://www.cr.nps.gov/history/online_books/science/2/chap10.htm
accessdate = 2007-12-15 (Date of webpage - 2005-04-01.)
*
* cite web
title = Elevations and Distances in the United States
publisher = U.S. Geological Survey
url = http://erg.usgs.gov/isb/pubs/booklets/elvadist/elvadist.html#Highest
accessdate = 2007-12-15 (Date of webpage: 2005-04-29.)
* cite web
title = Geologic History of the Anoka Sandplain
work = Guide to Anoka County's Natural Resources
publisher = Anoka County Conservation District
url = http://www.anokanaturalresources.com/soil/geo_his_sandplain.htm
accessdate = 2007-12-15
* Jirsa, Mark and Southwick, David. cite web
title = Mineral Potential and Geology of Minnesota
publisher = Minnesota Geological Survey, University of Minnesota
date = 2003-12-01
url = http://www.geo.umn.edu/mgs/mnpot/MnpotGlg.html
accessdate = 2008-04-13
* cite web
last = Jol
first = Harry M.
title = Interstate State Park, A Brief Geologic History
publisher = University of Wisconsin at Eau Claire
date = 2006-12-06
url = http://www.uwec.edu/jolhm/Interstate2006/history.htm
accessdate = 2007-12-15 (Date of webpage = 2005-04-01.)
* cite web
title = Minnesota
work = America’s Volcanic Past: Places
publisher = U.S.Geological Survey, Cascades Volcanic Observatory
url = http://vulcan.wr.usgs.gov/LivingWith/VolcanicPast/Places/volcanic_past_minnesota.html
accessdate = 2007-12-15 (Date of webpage: 2003-01-26.)
* cite web
title = Minnesota Wind Energy Development
work = Wind Project Data Base
publisher = The American Wind Energy Association
url = http://www.awea.org/projects/minnesota.html
format =
doi =
accessdate = 2007-12-15 Date of webpage: (2007-03-31.)
* cite web
title = Natural History - Minnesota's Geology
publisher = Minnesota Dept. of Natural Resources
url = http://www.dnr.state.mn.us/snas/naturalhistory.html
accessdate = 2007-12-15 (Date of webpage: 2007.)
* cite web
title = Patterned peatlands near Ludlow Lookout, Northern Beltrami County, MN
work = Aerial photograph
publisher = U.S.G.S, via terraserver.microsoft.com
url = http://www.terraserver.microsoft.com/image.aspx?T=1&S=15&Z=15&X=59&Y=835&W=1&qs=%7cWaskish%7cMN%7c
accessdate = 2007-12-15 (Date of photograph: 1991-04-25.)
* cite web
last = Townsend
first = Catherine L.
coauthors = Figge, John T.
title = Dance of the Giant Continents
work = Northwest Origins
publisher = Burke Museum of History and Culture, University of Washington
date = 2002
url = http://www.washington.edu/burkemuseum/geo_history_wa/Dance%20of%20the%20Giant%20Continents.htm
accessdate = 2007-12-15
* cite web
title = Wetlands
work = Fact Sheets
publisher = Minnesota River Basin Data Center, Minnesota State University, Mankato
url = http://mrbdc.mnsu.edu/mnbasin/fact_sheets/wetlands.html
accessdate = 2007-12-15 (Date of webpage: 2004-11-15.)
* cite web
title = Wetlands Component Assessment Regions
work = Map 9726
publisher = National Resources Conservation Service, United States Department of Agriculture
url = http://www.nrcs.usda.gov/Technical/nri/ceap/images/ceap_wetlands_map.gif
accessdate = 2007-12-15 (Date of

United States topic
title = Geology of the United States by political division
prefix = Geology of