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May 20 2012

My Brain Feels Like It’s Been Through Several Orogenies

I’ve been lying abed for the last several hours with a happy napping felid and books. Deciding to take a break from an extensive paper on Mount St. Helens’ eruptive history, I dipped in to Written in Stone, my second-favorite book of that title (the first being the one by Brian Switek, of course). I’ve not read it in years. Now that I’ve been to New England, I thought, this is a prime time to peruse it again.

This lead to the realization that Evelyn and I were gallivanting over several exotic terranes. The trouble is, I can’t figure out which ones. In over an hour of spelunking the intertoobz, I’ve come across no end to geologic maps, some showing terranes, all of them seeming to show different terranes for the same area. Argh. If anyone has a good source on the terranes of New England, especially New Hampshire, Massachusetts and Vermont, now would be a perfect time to say so.

Here’s a map of all the places we went, for those who wish to see my area of focus:

View Larger Map

My geologic experiences up to this point have been largely confined to the American West. There’s an advantage the West has: there’s a lot more written about the geology out here. Papers are easier to find, books abound, the state geological surveys are fairly comprehensive and have lots of publications online. I’ve only begun to search the East, but it seems these things aren’t quite as true for New England. Sigh.

There’s also the advantage of living here. I’ve spent my entire life poking round the western rocks. I know them intimately. Even the Pacific Northwest, which I’ve only lived in for five years, is as familiar as my cat’s dear fanged face. The East is alien. I’m not used to passive margins (which in the past weren’t passive at all). Some of the rock types we found were cheerily similar, like seeing old friends. But the regional geology might as well be Martian. I haven’t got a grasp of it. I mean, I know some things, but they’re broad strokes. The canvass has been prepared, a few things sketched in, but not so much as a dab of paint put in.

And the geography scrambles my brain. Evelyn and I drove for two hours. In my part of the country, you’re lucky to leave a county in that amount of time, much less cross a state line. We’d crossed three. And, because I’m used to barely scratching the surface of another state in several hours of driving, I’d got the impression Holyoke, Mass was close to the New Hampshire/Vermont borders. Not so. We’d practically made it to Connecticut. This blows my Wild West mind. This does not happen where I come from.

After a few hours, I’m getting the shapes of the states and their relative positions firm in my mind, able to recognize them from a small slice on a map when there’s no anchor like New York to guide me. I’m starting to get a tiny sense of the regional geography. But it’s going to take an incredible amount of work to even begin to understand what we saw. I’ll likely be screaming for help from those more well-versed in New England geology.

I’m tapping my foot and checking my watch at the people who’re supposed to be bringing us closer to this brave new world of man-machine merging, because I could use an upgrade to my brain. I want to be able to stream geology papers directly into my brain. I want to be able to overlay geologic maps with political and topographic maps and understand them, merely by telling that upgraded portion of my mind to go seek out the desired info and make it usable. I want to step into virtual reality and learn this stuff by taste and touch and smell.

I stood out on the porch this evening cursing the fact I’ll always be downright stupid about particular regions of the world. I want to know them all. Intimately. And once I’m done with them, there’s plenty of other planets in the solar system. And beyond: a universe.

This is the only reason I ever crave immortality. I don’t want power. Don’t even necessarily want fame and fortune (although with a fortune, I could subscribe to journals and buy the really expensive books and travel to all the nifty places, so on second thought: fortune, too, please!). I’d just like all that time to immerse myself in science. I’ll start with geology, but I want it all. Every single branch. I want to know all we know in all of the physical sciences, and then I want to plunge headfirst into those brave new worlds were questions outnumber answers and the words on everyone’s lips are, “I don’t know. Let’s find out!”

But I’ll do the best I can with my finite span. After letting my poor brain catch a break by allowing it to return to the easy, quiet rhythms of volcanic eruptions, I’ll plunge it right back into orogenies again. It may end up feeling like a migmatite before we’re done, but we will be able to speak with a semblance of intelligence about New England geology.

And from there, the world…

6 comments

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  1. 1
    F [i'm not here, i'm gone]

    Ha! My brain, too. I was just poking around through the Grenville, Taconic, Acadian/Caledonian, Alleghenian orogenies yesterday. God only knows what terrane you were standing on, but someone will probably sort it out eventually.

    Where I am, the crystalline basement is somewhere below the ninth circle of hell. I’ve never found a satisfactory answer as to when this was accreted to the craton (which, of course, is made up of terranes anyway).

    Of course, there is some ambiguity in terrane boundaries, and some of this seems to be increased in literature by geologists focusing on a certain scale for purposes of their work. Some terranes are made up of smaller terranes… So good luck!

  2. 2
    F [i'm not here, i'm gone]

    The shorter version, if one will allow me to accrete this onto my previous post, is that all the good stuff is in pricey paper-only books or behind a paywall in fragments.

  3. 3
    Ron Schott

    There are at least three things working against your understanding of New England’s geology:

    1) There’s generally much less exposure of bedrock than many regions of the western USA. That can be both a blessing and a curse, but it certainly means there’s much more room for interpretation, and no two geologists seem to draw the same interpretations from the limited data.

    2) As complex as some areas of the western USA are, the northeast has been through much more geologic action, and not nearly as recently. Geologists tend to work backwards from the present when deciphering the geologic history of an area. The further back in time you go, however, the more the clues have been obscured by more recent events. In an area that experienced multiple overprinting orogenies, like New England, the clues can be extremely jumbled and obscure.

    3) Geologists have been working on trying to understand New England’s geology for so long that there are many more explanations out there (many outdated). I suspect there’s a lot more literature on New England geology that’s buried in scientific journals, thesis, and printed reports than you realize, in large part because much of that has never made its way onto the web in an accessible manner. In many ways, the obscurity of the literature may mirror the obscurity of the bedrock.

    I suspect it’s much easier for a geologist who’s learned how to practice geology in the complicated and obscure eastern USA to make the transition to the better exposed western USA than vice versa. Anyhow, that’s been my path. :-)

  4. 4
    Lyle

    Here is a nice history of the northern applacians.
    http://www.scec.org/instanet/01news/es_abstracts/brownEarthScopeWorkshop.pd
    And another nice series of pages:
    http://www.jamestown-ri.info/northern_appalachians.htm

    Now one must understand that details are in many cases “not well understood” i.e. geologists differ on what happened. For example the article notes that the Taconic really was a number if Island Arcs, as indeed Avolonia (Acadian oregeny) was followed by northern europe. (both collided at that time).
    So in some sense beyond saying that the rocks in some areas were affected by a given oregeny little is agreed on. For example there seems to be no work breaking down which island arc left which pieces. Of course part of it is that then the Appalachian oregeny mixed things up further.

    If you don’t already have it the geological highway map can help, along with RoadSide geologies of Vermont and New Hampshire and Mass. (2 books) That will tell the age of rocks in places and with the history you can deduce some of the general history.

  5. 5
    Tamsin

    This sounds like how I felt after a week doing fieldwork at Kekerengu – trying to make sense of the Rangitata Orogeny and the still-ongoing Kaikoura Orogeny on this little area full of folds, faults, faulted folds, etc. You have my sympathy, but I’m afraid all I know about New England geology is that there are moraines and roxbury puddingstone.

  6. 6
    Lyle

    Have you seen the series in Hudson Valley Geologist on the Hudson valley. From his day 6 posting: http://hudsonvalleygeologist.blogspot.com/2012/05/day-6-hudson-valley-fold-thrust-belt.html

    Still, generations of geologists haven’t really settled one important fact about these rocks – which orogenic event(s) deformed them – Acadian (Devonian) and Alleghanian (Pennsylvanian/Permian) or two different phases of the Alleghanian.”

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