Wednesday, December 12, 2012

Comment & a couple of mine pics

So, I haven't been posting much at all this fall as I've been mega-busy with my job as professor and department chair.  I also taught a bunch of extra courses above and beyond my required course load (I needed the money) so many non-essential things (like this blog) took a backseat.  Things are calming down now as we enter final exams so I hope to begin posting more.

One of the projects I have to get to is my external hard drive which has something like 100 GB of pictures that are in complete disarray and need to be sorted.  It's starting to get annoying because I'll be lecturing on, for example, geysers in Yellowstone and I know I have pictures I've taken from several trips there in the past but can't immediately put my finger on the pictures.  It's a heck of a lot of work to sort images.  They're in folders so my plan over break is to just sort a few folders a week, a little at a time, so that the scary, unmanagable-looking job is broken down into smaller bite-sized chunks that are doable.

As I go through the images, I'm sure I'll find many I can post to comment on in the blog.  Here are a couple to start things off...

This is an image of a Rosendale cement mine from 1920 taken by Harold Wanless (1898–1970) - then a Princeton University and later professor for 44 years at the University of Illinois (which I also attended for a time).  Around this time, the Princeton geology department led yearly trips up to the Rosendale, NY area to study the geology here (I live in the town of Rosendale myself).  There's a lot more I can write about this, but it will have to wait for another time.

The mines are still here.  This is a modern shot of a Rosendale cement mine, taken by me a couple of years ago.  The rock unit missing (but still preserved in the pillars) is the Rosendale dolostone member of the Rondout Formation.  Mined, baked in a kiln, and then crushed, it made an excellent natural cement that was world-famous at the time.  The roof of the mine is the Glasco limestone member of the Rondout Formation, which did not make a good natural cement so was left behind.

Note the tilt of this mine as it dips downward to the right?  That's because these Upper Silurian Period (~420 million-year-old) rocks were folded (and faulted) long after they were deposited on an ancient seafloor as witnessed by the coral fossils and calcarous sponges (stromatoporoids) in the Glasco.

Above is a picture from Wanless.
And this is my own.  The 100-year span of time between these images seems like a long time, but multiply that 100 years by about 4,000,000 to get back to the time these guys were sitting on a subtropical seafloor here in what was to become the Hudson Valley.  I still think that's pretty cool!

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