This photo is from the Millboro Formation: mostly deep water black shale, but with the occasional heavy turbidite coursing in and settling its bulk down on the squishy mud beneath. Some folks on our trip suggested these might be seismites: soft sediment deformation resulting from earthquake-induced vibration.
Hoo-hoo! An anticline in the hanging wall of a thrust fault in the Valley & Ridge. This is the redbeds of the latest-Ordovician Juniata Formation. Lynn Fichter for scale.
Where are some ripple marks in the Hampshire Formation. Cell phone service is a lot more localized here in West Virginia, so we’ll see how many posts I manage today…
Bedding and cleavage intersect in the Weverton Fm. Bedding = Cambrian Cleavage = late Paleozoic (Alleghanian)
Last Friday, I spent the evening riding up to New York on a bus. To pass the time, I had my iPod and a new paper by Francis Macdonald and colleagues in Science. The paper examines the timing of one of the episodes of “Snowball Earth” glaciation. There’s some important new data in this paper, … Read more
Another in the Geology Of Central Park series…
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My girlfriend’s mom was in town in January, and we took her down to visit the Capitol Building. The tour had a good bit of history, but definitely missed the opportunity to talk geology. I was particularly struck by the columns in the Hall of Statuary: Close up of one column, with my hand for … Read more
So, those sediments we saw yesterday? They’re faulted in the area around the Crucifix Site. As this image shows, the style of faulting is normal faulting: Annotated with some color to jazz things up a bit: In normal faults, the upper block moves downward with respect to the lower block. They are typical of extensional … Read more
On the September 2009 GSA field forum in the Owens Valley, the final stop of our first day was to check out the so-called “Crucifix Site,” along Chalk Bluff Road (north of Bishop, California, at the southern margin of the Volcanic Tableland). It’s called the “Crucifix Site” because there is a metal cross erected there: … Read more