Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Michigan, USA

This page is currently not sponsored. Click here to sponsor this page.
Bedrock geology map of Michigan

Michigan, USA
Geological map

Michigan, USA
Bedrock geology map of Michigan

Michigan, USA
Geological map

Michigan, USA
Bedrock geology map of Michigan

Michigan, USA
Geological map

Michigan, USA
 


Introduction

The State of Michigan is unique in that it is separated into two geographically distinct regions that are, for the most part, geologically different as well. The State is divided into an Upper and Lower Peninsula, separated by the Straits of Mackinaw between Mackinaw City and Saint Ignace. The state is divided by geology as well and features two very distinct areas. The first area includes all of the Lower Peninsula and approximately one-half (the eastern) portion of the Upper Peninsula, which consist mostly of Paleozoic aged sediments (mostly limestone and dolomite). The second area is the western half of the Upper Peninsula which is dominated by Archean and Proterozoic Precambrian aged gneiss, granites, basalts, and sandstones.

The boundary between the sediments to the east and mostly Precambrian rocks to the west extends from approximately Marquette in the north to Iron Mountain in the south. The following is a very brief description of the geology of Michigan. For a more detailed read, please see the many books published on the subject.

Precambrian Geology

The Precambrian rocks that dominate the western half of Michigan’s Upper Peninsula are very diverse and include both intrusive and extrusive varieties, as well as sediments and their metamorphic equivalents. Rocks of this period include those of the Canadian Shield, the Banded Iron Formations, and the Portage Lake Volcanics. Outcrops of these rocks can be found scattered throughout the area; however, in most cases, the rock record is either fragmentary and incomplete, or buried under overburden left by the glaciers.

Since their formation, much has happened to these rocks. The oldest, the Watersmeet Gneiss, has been dated to 3.56 billion years old, making it some of the oldest rock in North America. The Watersmeet Gneiss, as well as many other of the oldest rocks, have been subjected to at least three major crustal deformations and mountain building events. In addition, there have been at least four smaller scale deformation events in the area. These events were accompanied by the intrusion of granitic rocks deep within the crust that were later brought to the surface by uplift and erosion. In addition to the granitic intrusions, at least four periods of volcanism have been discovered that produced basalt rocks and pyroclastic deposits, as well as dikes and dike swarms composed of diabase and gabbro.

Since their formation, metamorphism of these rocks has produced a multitude of new and reworked rocks and minerals. The greenstone, gneiss, quartzite, marble, slate, and schist found throughout the western Upper Peninsula can all trace their roots to much older rocks. The youngest rocks in this group are the Portage Lake Volcanics, which include basalts, conglomerates, and sandstones. These packages of rocks have remained largely unchanged since their formation, except for very shallow burial metamorphism of the basalts to the prehnite/pumpellyite grade. Rocks of the Portage Lake Volcanic series are associated with the Midcontinent Rift, a great tear in the Earth’s crust that nearly separated North America in two. The Rift can be traced from near Detroit northwest through the Lower Peninsula into Lake Superior, then arching back southwestward across the Keweenaw Peninsula and into Wisconsin.

Many of the metallic mineral deposits in Michigan come from the Precambrian rocks of the western Upper Peninsula, including the world renowned native copper deposits on the Keweenaw Peninsula and the banded iron formation deposits of the Marquette, Menominee, and Gogebic Ranges. Other minerals of note to come from the Precambrian rocks include silver, prehnite, garnet, goethite, datolite, gold, and the famous Lake Superior agate.



Paleozoic Rocks

Rocks of the Paleozoic are represented by formations that underlie all of the Lower Peninsula and the eastern half of the Upper Peninsula. All of these rocks are sedimentary that were deposited in a shallow sea over a period of about 370 million years beginning in the Cambrian and lasting through the Pennsylvanian. During this time, approximately 14,000 feet of mostly limestones, dolomites, sandstones, and shales were deposited on top of the Precambrian basement rocks; the same rocks that are exposed in the western Upper Peninsula. As these sediments were being deposited, the entire region began to downwarp into a bowl-shaped depression. This depression, called the Michigan Basin, dominates the geology of the Lower Peninsula. The basin dips inward from the edges at approximately 2 degrees until reaching the center of the basin near the geographic center of the Lower Peninsula. Most of the Paleozoic rocks in the basin are derived from marine sediments; however, a few fluvial sandstones and coal deposits are exceptions.

What is unique about the entire sedimentary package is that they have not been metamorphosed or subjected to igneous intrusion or volcanism. Structurally, the rocks have not been subjected to major deformation except for minor folding and faulting near the edges of the basin. In essence, these rocks have remained sedimentary rock, modified only slightly by weathering and the action of groundwater. The rocks of the Paleozoic do not represent a complete record of sedimentation in the Michigan Basin. Several times during the sedimentation, uplift interrupted the sinking of the basin which is characterized by erosion, or at least non-deposition, and has created several time gaps, or unconformities. While very few metallic minerals are found in the Paleozoic rocks, almost all of Michigan’s oil and natural gas reserves are found in the Michigan Basin rocks. Also found in the basin are large economic deposits of limestone and dolomite, including the world’s largest limestone quarry located near Rogers City, and large salt deposits under Detroit, Michigan.

Post Pennsylvanian and Pleistocene Geology

This period is marked by the fact that very few rocks are found with an age between the end of the Pennsylvanian and the Pleistocene glacial deposits. This “Lost Interval” in geologic time is represented only by a small area of red beds located near the center of the Basin which are completely buried by glacial deposits and are only known from drill core data. The age of these red beds has been interpreted as youngest Jurassic based on fossil plant spores extracted from the drill cores. Beyond these rocks, no rock record is preserved from this period; this is likely due to a change from deposition to a period of slow erosion on the landscape until the Pleistocene Epoch and the arrival of the glaciers from Canada. It is known that at least four major glaciations took place during the Pleistocene, but only the youngest of these (the Wisconsinan) are preserved in Michigan. The surficial deposits from this epoch include clastic sediments, drift, gravels, sands, and clays. Surface features found scattered across both peninsulas that can be directly attributed to glacial activity include kettle lakes, eskers, lateral and end moraines, and kame deposits. The sediments carried in by the glaciers, while not loaded with economic minerals that can be mined, are very rich in nutrients that make them excellent for growing crops that supply food to millions of people around the world.

One additional rock type that deserves mention are the kimberlite deposits found in Upper Michigan. These kimberlites are thought to have been emplaced during the Cretaceous Period between 150 and 100 million years ago, during the time dinosaurs roamed the earth! First discovered in 1971, these deposits have generated much interest both popular and scientific. To date, no economic diamond deposit has been discovered in Michigan. It has been suggested that Michigan did not have the correct tectonic setting favourable for a highly diamondtiferous kimberlite. It is also believed that the Mid Continent Rift had a very destructive influence on the lithospheric mantle, thus destroying any diamonds being stored in the mantle prior to the kimberlite eruptions. Currently there is no active diamond exploration taking place in Michigan; however, there are a number of untested targets and placer deposits of indicator minerals occurrences in the state. Maybe one day, the state of Michigan will produce the next “diamond rush”?

The State of Michigan is unique geologically, and to truly understand its complexity the rocks must be seen in person and not simply read about in a textbook or trade magazine. Not many places on Earth can boast areas where a person can stand on 3.6 billion year old Archean gneiss then take one step and stand on glacial deposits just 7,000 years old; that is quite an amazing thought!
[Paul Brandes 2011]

Mineral List

Mineral list contains entries from the region specified including sub-localities

Acanthite

Actinolite

Aegirine

Aeschynite-(Y)

Albite

var: Andesine

var: Oligoclase

var: Peristerite

'Albite-Anorthite Series'

Algodonite

Allanite-(Ce)

'Allanite Group'

Almandine

Aluminoceladonite

Alunite

'Amphibole Supergroup'

'var: Uralite'

Analcime

Anatase

Andalusite

Andradite

Anglesite

Anhydrite

Anilite

Ankerite

Annabergite

Anorthite

var: Bytownite

var: Labradorite

Anthonyite (TL)

Anthophyllite

Antigorite

Antimony

'Apatite'

'var: Carbonate-rich Apatite'

'var: Collophane'

'Aphrosiderite'

'Apophyllite'

Aragonite

var: Flos Ferri

Argentopentlandite

Arsenopyrite

'Asbestos'

Atacamite

Augite

'Axinite Group'

Axinite-(Mg)

Azurite

Babingtonite

Baddeleyite

Baryte

Bassetite

'Bastnäsite'

Bastnäsite-(Ce)

Bastnäsite-(Y)

Bertrandite

Beryl

'Betafite Group'

'Biotite'

Bismuth

Bismuthinite

'Bitumen'

Bornite

Brannerite

Braunite

Britholite-(Y)

Brochantite

Brookite

Brucite

Buttgenbachite

Calcite

var: Anthraconite

var: Manganoan Calcite

Calcurmolite

Calumetite (TL)

Carbonatecyanotrichite

Carnallite

Cassiterite

Celadonite

Celestine

Centennialite (TL)

Cerussite

'Chabazite'

Chalcanthite

Chalcocite

Chalconatronite

Chalcopyrite

Chamosite

var: Thuringite

Cheralite

'Chert
var: Taconite'

Chervetite

Chlorapatite

Chlorartinite

'Chlorite Group'

'var: Brunsvigite'

Chloritoid

var: Masonite

Chromite

Chrysocolla

Chrysotile

Cinnabar

Clausthalite

Clinochlore

var: Delessite

var: Diabantite

var: Pennine

var: Ripidolite

Clinochrysotile

'Clinopyroxene Subgroup'

Clinozoisite

Cobaltite

'Columbite'

Columbite-(Fe)

'Columbite-(Fe)-Columbite-(Mn) Series'

Connellite

Copiapite

Copper

'Copper Stain'

Cordierite

Coronadite

Corrensite

Corundum

Cosalite

Covellite

Crednerite

Cryptomelane

Cubanite

Cummingtonite

Cuprite

var: Chalcotrichite

Datolite

Daubréelite

Diamond

Diaphorite

Dickite

Digenite

Diopside

var: Schefferite

Dioptase

Djurleite

Dolomite

var: Ferroan Dolomite

Domeykite

Dyscrasite

Edenite

Enargite

Enstatite

var: Bronzite

Epidote

Epsomite

Erythrite

Euclase

Eugenite

Euxenite-(Y)

Fassinaite

'Faujasite Subgroup'

Fayalite

'Feldspar Group'

'var: Perthite'

Ferberite

Ferrimolybdite

Ferro-hornblende

Fluorapatite

Fluorapophyllite-(K)

Fluorite

var: Chlorophane

var: Yttrofluorite

Forsterite

Gahnite

Galena

Galenobismutite

'Garnet'

Geikielite

Gerhardtite

Gersdorffite

Gibbsite

Glauconite

Goethite

Gold

var: Electrum

Graphite

Grayite

Greenalite

Greenockite

Greigite

Groutite

Grunerite

Guérinite

'Gummite'

Gypsum

var: Alabaster

var: Satin Spar Gypsum

var: Selenite

'Halfbreed'

Halite

'Halloysite'

Halotrichite

Hausmannite

Hedenbergite

Hematite

var: Martite

var: Specularite

Hessite

Hetaerolite

'Heulandite'

Heulandite-Ca

Hexahydrite

Hisingerite

Hollandite

'Hornblende'

Humboldtine

Hydrocerussite

Hydromagnesite

Hydroxylapatite

var: Carbonate-rich Hydroxylapatite

Hydrozincite

'Hypersthene'

'Iddingsite'

Ilmenite

Iron

var: Kamacite

var: Martensite

Isocubanite

Jacobsite

Jarosite

'Jaspillite'

Kamiokite

Kaolinite

Kasolite

'Kelyphite'

'K Feldspar'

'var: Adularia'

Kinoite

Kochkarite

Koutekite

Kutnohorite

Kyanite

Langite

Laumontite

Lavendulan

Lechatelierite

Lepidocrocite

Leucoxene

Likasite

'Limonite'

Lizardite

Luanheite

Macfallite (TL)

Mackinawite

Magnesio-riebeckite

Magnetite

Malachite

'Manganese Oxides'

'var: Manganese Dendrites'

Manganite

Manganocummingtonite

Marcasite

Margarite

Maucherite

Meionite

Melanterite

'Melilite Group'

Meneghinite

Mercury

Merrillite

Mesolite

Meta-autunite

Metacinnabar

Metatorbernite

Metatyuyamunite

'Mica Group'

Microcline

var: Ferruginous Microcline

Microlite Group

Millerite

Mimetite

Minnesotaite

Mirabilite

'Mohawkite'

Molybdenite

'Monazite'

Monazite-(Ce)

Monohydrocalcite

Monticellite

Montmorillonite

Montroseite

Moolooite

Mottramite

Muscovite

var: Fuchsite

var: Illite

var: Sericite

Nacrite

Nantokite

Natrojarosite

Natrolite

Neltnerite

Neotocite

Nickeline

Nickelskutterudite

Nontronite

Olivenite

'Olivine'

Orientite

'Orthochamosite'

Orthoclase

'Orthopyroxene Subgroup'

Otavite

Palygorskite

Paragonite

Paramelaconite

Pararammelsbergite

Paratacamite

Pargasite

Paxite

Pecoraite

Pentlandite

Perovskite

'Petoskey Stone'

Pharmacolite

Phlogopite

Pickeringite

Picropharmacolite

Pigeonite

Plancheite

'Plessite'

Polyhalite

Posnjakite

Powellite

Prehnite

Pseudomalachite

'Psilomelane'

'Pumpellyite'

Pumpellyite-(Fe2+)

Pumpellyite-(Mg) (TL)

var: Chlorastrolite

Pumpellyite-(Mn2+)

Pyrite

var: Bravoite

'Pyrochlore'

Pyrochroite

var: Hydrohausmannite

Pyrolusite

Pyrope

Pyrophyllite

Pyrostilpnite

Pyroxmangite

Pyrrhotite

Quartz

var: Agate

var: Amethyst

var: Carnelian

var: Chalcedony

var: Lake Superior Agate

var: Milky Quartz

var: Rock Crystal

var: Smoky Quartz

Ramdohrite

Rammelsbergite

Ranciéite

Rauenthalite

Rhodochrosite

Rhodonite

Riebeckite

Romanèchite

Rutherfordine

Rutile

Safflorite

Sainfeldite

Sanidine

Saponite

'Scapolite'

Scheelite

Schorl

Schreibersite

Seamanite (TL)

Sepiolite

'Serpentine Subgroup'

'var: Picrolite'

Shigaite

Shuiskite

'Shungite'

Siderite

Siegenite

Silicon

Sillimanite

Silver

var: Amalgam

Sklodowskite

Skutterudite

'Smectite Group'

Smithsonite

Spertiniite

Spessartine

Sphalerite

Spinel

Spodumene

Starkeyite

Staurolite

'Stilbite'

Stilbite-Ca

Stilpnomelane

Stromeyerite

Strontianite

Sudoite

Sulphur

Sussexite

Sylvite

Synchysite-(Ce)

Synchysite-(Y)

Szaibélyite

Taenite

Talc

var: Beaconite

var: Steatite

Tangeite

Tantalite-(Fe)

Tanteuxenite-(Y)

Tapiolite-(Fe)

Tellurium

Tellurobismuthite

Tenorite

Tetrahedrite

var: Argentian Tetrahedrite

Tetrataenite

Thermonatrite

'Thomsonite'

Thomsonite-Ca

Thorite

Titanite

Topaz

'Tourmaline'

Tremolite

Troilite

Trona

Tsumoite

Tyrolite

Tyuyamunite

'UM1986-25-P:Ti'

Uraninite

var: Pitchblende

var: Thorian Uraninite

Uranophane

Uranospinite

Uvarovite

Vaterite

Vermiculite

Veszelyite

Violarite

Vivianite

Vladimirite

Volborthite

Volynskite

Vonsenite

Wairakite

Wakefieldite-(Y)

Whewellite

Widenmannite

Wilcoxite

Witherite

Wollastonite

Wroewolfeite

Wulfenite

Wurtzite

Xenotime-(Y)

Xilingolite

Xonotlite

Zangboite

Zircon

var: Hyacinth

Zoisite


359 valid minerals. 6 (TL) - type locality of valid minerals.

Rock Types Recorded

Entries shown in red are rocks recorded for this region.

Note: this is a very new system on mindat.org and data is currently VERY limited. Please bear with us while we work towards adding this information!

Rock list contains entries from the region specified including sub-localities


Localities in this Region


The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Carlson, S.M., and Floodstrand, W., 1994. Michigan Kimberlites and Diamond Exploration Techniques (abstract), in Institute on Lake Superior Geology Proceedings, 40th Annual Meeting, Houghton, Michigan, v.40, part 4.

Dorr, J.A., and Eschman, D.F., 1970. Geology of Michigan: University of Michigan Press, 476 p.

Dyl, S.J., and Wilson, M.L., 1992. Michigan Copper Country: Mineralogical Record, v.23, no.2, p. 24-28.

Heinrich, E.W., 1976. The Mineralogy of Michigan: Michigan Department of Natural Resources, Geological Survey Division, Bulletin 6, 225 p.

LaBerge, G.L., 1994. Geology of the Lake Superior Region: Geoscience Press, 313 p.

Robinson, G.W., 2004. Mineralogy of Michigan: Michigan Technological University, 252 p.

External Links


Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2016, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: December 6, 2016 08:07:02 Page generated: December 1, 2016 13:35:46
Go to top of page