🔎 UNIDENTIFIED Trying to learn about geology

Blackfoot58

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Jan 11, 2023
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Iowa
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Several times recently I’ve been walking in my timber and have spotted large pieces of: granite, feldspar, jasper, etc sticking out of the ground. They are often bigger than a baseball. There doesn’t appear to be any rock veins running through the property. Would the pieces be from glacial activity? Would they have been carried there by NAtive Americans? To me it’s like finding an acorn 10 miles from the nearest oak.
I’ve found arrowheads in the same timber. Just wondering if these could have been “brought in”.
 

Solution
The Southern Iowa Drift Plain (marked in green below) is dominated by glacial deposits left by ice sheets that extended south into Missouri over 500,000 years ago. The deposits were carved by deepening episodes of stream erosion so that only a horizon line of hill summits marks the once-continuous glacial plain. Numerous rills, creeks, and rivers branch out across the landscape shaping the old glacial deposits into steeply rolling hills and valleys. A mantle of loess drapes the uplands and upper hill slopes. [Source Iowa Geological Survey at the University of Iowa]

Iowa.jpg
Where are you located? Glacier brought tons of rock to cent. IL.
Iowa. We too had glacial activity. More in the northern part of the state. I’m in the SE corner, but I still suspect glaciers scattered these rocks.
 

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The Southern Iowa Drift Plain (marked in green below) is dominated by glacial deposits left by ice sheets that extended south into Missouri over 500,000 years ago. The deposits were carved by deepening episodes of stream erosion so that only a horizon line of hill summits marks the once-continuous glacial plain. Numerous rills, creeks, and rivers branch out across the landscape shaping the old glacial deposits into steeply rolling hills and valleys. A mantle of loess drapes the uplands and upper hill slopes. [Source Iowa Geological Survey at the University of Iowa]

Iowa.jpg
 

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Solution
The Southern Iowa Drift Plain (marked in green below) is dominated by glacial deposits left by ice sheets that extended south into Missouri over 500,000 years ago. The deposits were carved by deepening episodes of stream erosion so that only a horizon line of hill summits marks the once-continuous glacial plain. Numerous rills, creeks, and rivers branch out across the landscape shaping the old glacial deposits into steeply rolling hills and valleys. A mantle of loess drapes the uplands and upper hill slopes. [Source Iowa Geological Survey at the University of Iowa]

View attachment 2070873
Thanks
 

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I picked up some really nice flint (chert) in SE IA. I think it was near Mt. Pleasant. It was a county owned limestone quarry that was abandoned because limestone contained too much chert. The chert ended up crushed and put on country roads and caused too many flat tires. Quarry is on main road heading SW out of Mt. Pleasant on left right before you cross the river.
 

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I picked up some really nice flint (chert) in SE IA. I think it was near Mt. Pleasant. It was a county owned limestone quarry that was abandoned because limestone contained too much chert. The chert ended up crushed and put on country roads and caused too many flat tires. Quarry is on main road heading SW out of Mt. Pleasant on left right before you cross the river.
I’ll check it out. I’m only 30 miles from there. Thanks!
 

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I grew up in Iowa from 1965-77 and the surface of the state is scattered with a verity of rubble that has been bulldozed all the way from Canada by massive glaciers. Some rocks can be rather large and known as glacial erratics.

What you've described as jasper, may have been transported by humans as raw materials to fashion stone tools. They would have wanted to have that on hand to use or trade any good pieces of microcrysaline materials for their way of life.

There's a few good books on the geology of Iowa. A lot more went on over time there than what you see. Read a couple of them and you'll begin to see so much more of the state.
 

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I grew up in Iowa from 1965-77 and the surface of the state is scattered with a verity of rubble that has been bulldozed all the way from Canada by massive glaciers. Some rocks can be rather large and known as glacial erratics.
A friend of mine does dirt work: dozing, trenching, etc. He often finds 4-5 ft dia. Boulders. They usually become yard ornaments. The pic you sent is very impressive. Thanks
 

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I declared a solution and marked it as such. I cannot get the Unidentified label to change to Solved. Not sure why. I’ve done several of these successfully in the past.
 

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I declared a solution and marked it as such. I cannot get the Unidentified label to change to Solved. Not sure why. I’ve done several of these successfully in the past.
Yeah I need to put a little thought into how to do it myself each time, but it's there somewhere. I don't have a working laptop anymore. I'm on two years or more all on a phone. Everything from keeping up with family and business contacts through emails and text. I'm still looking for the way on how to cast banner votes on the site using the phone. Haven't figured that one out yet. I probably need the download an app or something that everyone else knows, but me.
 

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I read where the edit button disappears after so long, to prevent adult children from deleting. I also read where you need to push Edit, before you can change the flag to Solved. I’m guessing this can’t be done because of the missing Edit button. Some posts take a while to get solved. I guess they remain mislabeled Unidentified forever. ?
 

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