Outcrop LocationLake Shore Welcome Center (quarry across US 41)
2208 U.S. 41 Marquette, MI 49855 This outcrop is located across US 41 from the Lake Shore Welcome Center. The owner of the quarry asks that you sign in at the Welcome Center before taking a gander at the awesome quarry. In the quarry, you'll see the Mona Schist (Archean in age) as well as the Mesnard Quartzite and the Kona Dolomite. This locality represents a syncline that is located within the larger Marquette Synclinorium (a Penokean orogeny feature). The rocks located here are tilted to almost a 90°-angle. As you walk northward in the quarry, you are getting younger, geologically. There is an illustrated outcrop guide located in the Welcome Center if you'd like to use it for reference while exploring. |
Mesnard Quartzite The Mesnard Quatrzite unconformably overlies the Enchantment Lake Formation, but more specifically, a paleosol that developed on the upper, aerially exposed surface of the glacial diamictites. Before it was metamorphosed into a quartzite, the Mesnard Quartzite was deposited as an orthoquartzite, or a very mature (composed mostly with quartz sand grains) sandstone. It is interpreted to have been deposited during a marine transgression along the continental margin of the Superior Province.
Kona Dolomite The Kona Dolomite is a stromatolitic unit that was deposited on top of the Mesnard Quartzite. Stromatolites can be found at the Harvey Quarry locality. The depositional environment is similar to that of the quartzite, in that the margin was a shallow marine shelf that was experiencing a marine transgression. Unfortunately, on this trip, we were not able to find the stromatolites, and so there are no photos.
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