Two xenoliths

On my last day in Ankara Turkey (last Friday), I took the afternoon off from the Tectonic Crossroads conference in order to pay the requisite visit to the Museum of Anatolian Civilizations. I say “requisite” because Ankara’s not quite so thrilling a town as Istanbul, but this is the one location that everyone agrees is worth a visit. The previous day at breakfast in our hotel, University of Georgia geology professor Jim Wright told me it was the most amazing place he had ever seen. So I had to go check it out for myself.

It’s a cool place, if you’re into history. Anatolia (the Asian part of Turkey, which is to say, most of Turkey) is a place steeped in history. Their written records go back 9000 years, if you include Neolithic cave paintings. It’s pretty neat to check out their sculptures and tools over that long span of time. (See some photos here.)

I only took one picture in the museum, though. This is it:

xeno_1

That’s a Hittite lion sculpture made of porphyritic andesite. I took his portrait because of that funny looking eyebrow — that’s a little black xenolith, a chunk of pre-existing solid rock that got stoped off the wall rock and carried along in the flow of magma, eventually getting trapped in “alien” territory once the magma (or lava) solidified around it into rock. It was the most striking geological aspect of the museum’s many displays.

After I got “museumed out” (usually this takes about 2 hours), I went for a walk around the adjacent “Citadel” region of old town Ankara, and what do you know, but I found an outcrop there! Not only that, but there were some striking similarities to the photo I had just taken in the museum — it was a porphyritic volcanic rock (I want to call it a rhyolite based on the pink color), and it too had a lone dark xenolith:

xeno_2

A little girl wandered up to me with unabashed curiosity — why was this foreigner putting a lira coin on the rock and taking a photo of it in the rain? Plainly, I must be insane. I greeted her, pocketed my coin, and strolled on, reflecting on the satisfaction of seeing such a nice little pairing of similar structures in similar rocks — a quarter mile from one another, though in very different settings.

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