Friday folds: Turpan Depression

Rob Simmon of NASA’s Earth Observatory is the source for today’s Friday folds. Last week, he tweeted this image to me: That’s a excellent example of the outcrop pattern of a more or less horizontal outcrop of folded rock. To the north is a synform (notice that where streams have eroded it, the bull’s-eye pattern … Read more

Rumeli Hisarı

Right after I got to Istanbul on this most recent trip, I took a taxi from my hotel down to the Bosphorus, to check out the Rumeli Hisarı, a fort complex built in 1452 by Sultan Mehmet the II in anticipation of the following year’s siege of Constantinople. It’s constructed at the narrowest point on … Read more

Jointed Virgelle

One of the stops my Rockies students and I made this summer was a dinosaur paleontology tour through the Two Medicine Dinosaur Center in Bynum, Montana. The folks there are very accommodating, and at my request gave the class a bit of stratigraphic context for the dinosaur fossils. For instance, we visited the geologic formation … Read more

Turkey update

Hey there folks, Long tıme no blog. I am enjoyıng Turkey. We spent several cool days ın Istanbul, checkıng out the awesome buıldıngs and twısty streets and great food there. Took a boat tour up the Bosphorus, walked across the Golden Horn. The Haghıa Sophıa ıs amazıng… a Chrıstıan cathedral datıng to Emporer Justınıan, then … Read more

The coming flood

In January, a large landslide occurred in the Hunza Valley of Pakistan’s Karakoram Range, near the village of Attabad. Like the Madison River landslide in Montana (1959), or the Gros Ventre landslide in Wyoming (1925), a river was dammed by the slide debris, and the impounded waters began to rise. At Gros Ventre, the landslide-dammed … Read more

Is this dike a feeder?

A new paper in the journal Geology examines an interesting question: how can you tell feeder dikes from non-feeder dikes? The answer is, normally you can’t. Normally, there’s no way to tell for sure whether a given dike actually funneled magma to the paleo-surface, or whether it never reached the paleo-surface. The reason for this … Read more