Monday, April 4, 2022

IS There A Dr. Of Geology In The House? - Updated

 

 Over the weekend, I dug this rock out of the yard and it caught my eye as to the porosity

and layering in the cross section.  To me I'm thinking maybe sedimentary rock? 

I rinsed it off and scrubbed it to get a better view.  There are glacial rocks and boulders

strewn all over New Hampshire. Back in the day, when the settlers cleared the land, they lined 

the boulders along lot lines or out of the way. There are hundreds and hundreds of rock 

walls running through the countryside. I found this one different only because there

is mostly granite around here. There are at least two ring dike volcanoes in NH as well. 

Just North of here. Some of that rubble may have been ablated and brought down this 

far as well. I 'll have to get more pictures of the other neat rocks that are about the property.

 


 


I will say it looks just like this image on the right hand side. It is an image of Gneiss 




18 comments:

  1. I am not a Geologist, nor have I stayed in a Holiday Inn Express (TM).

    That said, it looks like gneiss, a type of metamorphic rock that can be derived from igneous or sedimentary rock, IIRC.

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  2. Sorry if this double posts; fat fingers. I believe it’s quartzite. Quartzite is metamorphosed sandstone. In other words sandstone with a little heat and pressure. B.S. in Geology from Ashland University 1996

    -Chad

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    1. Thanks Chad. I'll try and clean it better when I get a chance. Others have said Gneiss.

      I found a picture that is very similar and updated the post

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    2. It could be. Crack it open with a hammer and get a picture of the unweathered surface. Since your area was glaciated; the rock doesn’t have to be from your area. It could be an erratic from Canada

      Chad

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  3. Did you find a tin full of money under it?

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    1. Wouldn't that have made for a better post??

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  4. Looks more like sedimentary rock than basaltic. Not a geologist or petrologist but the striations sure look like sediment deposits over time that then compressed into stone.

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    1. That's what I was thinking but there was no large bodies of water covering the area to allow that much sediment.

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  5. It is a Metamorphic rock called Gneiss pronounced Neese. It is German. It probably is over one billion years old. Quite common in your area

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    1. Thanks Ed. I appreciate the input. IT appears to be Gneiss from the picture search I did.

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    2. Lots of German in geology. Karst is about limestone and caves.

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  6. I minored in Geology in 1976. I won the Oregon 4H Rock Club Grand Prize exhibit at the State fair in 1964. It could be welded tuff. A product of pyroclastic flows. There's a lot in Oregon. You mentioned volcanic activity there. But yanno, I don't know because I'm a marine biologist. Not a geologist. But what I do know, rocks.

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  7. I like it! Nice find. No background from me, others seem to have covered it well.
    Ketanji Brown Jackson can't tell you what it is, but she can likely identify its gender. 🤣

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  8. That there is class A Schist!

    Chutes Magoo

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  9. The striations of lighter color look like limestone.

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