Pine Marten, Adirondacks

Hello everyone,

I’m back in my office after 7 weeks away. I had some great travels this summer, to Turkey, Montana, and New England… and great geological photos to share from each of those locations. I’m going to start off with something non-geological, though: something furry and alive!

Pine Marten

That, my friends, is a pine marten, a smaller relative of the fisher (“fisher cat,” in the local parlance) and a member of the Mustellidae, the weasel family of mammals. They are a vital part of the northern forest ecosystem, but rarely seen. This was the first time I have ever seen one in the wild: Lily and I were camping at Round Pond in the Adirondacks (near Keene Valley, New York), and this fellow was snuffling his way up the tree. When I called Lily over to see him, he froze, hunkered down, and stared at us for more than an hour. Sometime later, I looked back, and he was gone. For me, this was a great encounter… it was one of the few North American critters I haven’t yet encountered in the wild, and it was a pleasure to share the camp with it for a while.

I’ll be posting more regularly (and not just iPhone-uploaded photos) in the weeks to come. It’s good to be back.

Folds of New York

Thursday is ‘fold day’ here at Mountain Beltway.

Let’s take a look at some folds I saw last weekend in New York City. We’ll start with a bunch seen in the Manhattan Schist in Central Park. Here’s an example of the foliation in the schist. It’s got finer-grained regions and coarser, schistier regions with big honking muscovite flakes. Metamorphic petrologists: Does this correspond to paleo-bedding? (i.e. quartz-rich regions that metamorphose less spectacularly, and mud-rich regions that converted more totally to muscovite during metamorphism?)
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Anyhow, here’s what it looks like when it’s folded (accented with a small granite dike):

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And another, with some boudinage thrown in for flavor:

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This was one of the best outcrops I saw that weekend (on the edge of the ‘lake’), but it was inaccessible to closer photography. Sorry about all the branches in the image. What you’re looking at here is a series of folds with axes plunging at ~45° towards the lake:

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Crudely annotated version:

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Granite dike:

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Boudinaged granite dike:

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Folded and boudinaged granite dike #1:

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Folded and boudinaged granite dike #2:

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Lastly, here’s a couple of folds from inside the American Museum of Natural History. A metaconglomerate:
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A little model mountain belt made out of compressed sand layers:

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The thing that really struck me about this sand model is the folds visible in the green and yellow central part of the mountain belt: There are refolded folds there. The lower-central antiform with dark green atop yellow is the best example. I had the idea in my head that two generations of folds meant two generations of deformation, but here you’ve got two generations of folds resulting (presumably) from a single episode of ‘mountain building.’

Such beautiful complexity! I want a sand model like this for my lab.

Rusty weathering rind

On a granite block

Giant ground sloths

In the American Museum of Natural History:

These mylodontids reminded me of Puerto Natales

Where I am today

Graphics by USGS, after Schuberth, 1967.

Travertine nubbins on a bridge

Another in the Geology Of Central Park series…

Plumose structure

Propagation direction: upper left towards lower right:

Erratic

!!!

Glacial striations, southern Central Park

New York City has some cool geology: Paleozoic metamorphics scraped by Pleistocene glaciers.

Differential weathering in the Manhattan Schist

S.E. Central Park:

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