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U-M divers retrieve 8,900-year-old piece of wood from Lake Huron
Annarbor.com (12/12)
University of Michigan researchers announced they have found a 5 1/2 foot long, pole-shaped piece of wood that is 8,900 years old in Lake Huron.
Superior researchers studying invasives, ballast water
Ashland Current (2/9)
Determining how clean a ship's ballast water must be to prevent the spread of aquatic invasive species is the goal of the latest research partnership between the Northeast-Midwest Institute and the Lake Superior Research Institute at the University of Wisconsin-Superior.
RIVERKEEPERS: Tending the waterways
Niagara Gazette (2/6)
The goal of the Buffalo Niagara Riverkeeper is two-fold: protecting the water quantity and the quality, as well as connecting people to the waterfront.
Internationally renowned ‘Ocean Doctor’ to speak in Grand Rapids
MLive.com (2/3)
Known as the “Ocean Doctor,” David Guggenheim will speak in Grand Rapids, Mich., about the many similarities between the threats to the oceans and to our Great Lakes.
SUNY Fredonia to lead Great Lakes pollution study
Wall Street Journal (2/3)
Plastic pollution in the Great Lakes will be the focus of a study this summer. Led by the State University of New York at Fredonia, researchers will try to quantify the amount of plastic polluting the fresh water Great Lakes.
SSC students taking part in marine science bowl
Arenac County Independent (1/31)
Teams of Michigan high school students will be heading to Ann Arbor this weekend to take part in the annual Great Lakes Bowl, a quiz event that focuses on questions about marine and freshwater systems and biology.
What's going on in your neighborhood this month? Meet other people and learn together at recreational and educational events! Our new dynamic calendar is updated daily with current educational events.
What minerals or rocks are found in the Great Lakes region?
from Melissa in Ontario, Age 10 and
Ryan in Darien, Connecticut, Age 10
The primary rock exposed along the shore of Lake Ontario on both the US and Canadian shores in that area is an Ordovician age limestone about 400 million years old. Locally, it may contain some fairly large orthocone cephalopod fossils (including some that measure 6 feet in length!). This limestone is quarried both near Kingston, Ontario and in the Watertown, New York areas for crushed stone to be used in construction. Rarely, it may contain small veins that hold calcite crystals.
Further to the northeast in the Thousand Islands region lies an extension of the Canadian Shield known as the Frontenac Axis. This rock is mostly granitic gneiss and is about 1 billion years old (that's 1,000,000,000 years!).
There are many interesting, but small, pockets of other minerals in both these areas as well as in associated rocks that are inland from the St. Lawrence River on both sides of the border. Many on the Canadian side were worked for mica and apatite in the past, but are of no economic importance today. The only major economically valuable deposits still being worked in the area today are in the Balmat, New York district, where talc, wollastonite, and zinc are currently being mined.
The principal minerals found throughout the Great Lakes region include:
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Related references:
Great Lakes Atlas, 3rd ed.: Map of Geology and Mineral Resources
Michigan Technological University (MTU): A.E. Seaman Mineral Museum Photo Gallery
Illinois Department of Natural Resources (DNR): Office of Mines and Materials
Thank you for your question!
Answered on June 19, 2001 and updated on July 5, 2001