Sunday, September 29, 2019

2019 venture vermont: Identify each of these three types of rocks: igneous, sedimentary, and metamorphic.



i live in an area where the rocks are mostly metamorphic; i live near the spine of the Green Mountains, which have been raised and pushed and pressed so many times and in them you can see the folds and almost imagine days when they were plastic.

but to my west there are sedimentary rocks, the sandstones and shales of the Champlain Valley, and to my east are the granites of Barre and the northeast.

i went down into the bed of the Huntington River to look over some glacial till, because there you can usually find a lot of kinds of rocks.

i found this sandstone.

and this lovely banded gneiss.


and i thought maybe this was a granite, but it's not. it WAS a granite before it was metamorphosed, but now it's also gneiss.


so no big deal, right? if you can't find igneous rocks in the state of vermont, you are clearly not near barre, and not in the Northeast Kingdom. the geology of a lot of the state involves the Green Mountains, but west of that range are the Taconics (southwest corner) and just east of it are the great volcanic plumes of the Northeast Kingdom and the granite beds of Barre.

so, yanno. all you really have to do to find igneous rocks is head east of the Green Mountains and look for granite mountains or granite quarries, or really, you could just look for any modern cemetery or city edifice built of granite...

uh, anyway. up on owl's head in Groton State Forest are piles and piles of granites.


1 comment:

Zhoen said...

It's gneiss that you don't take it for granite.

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