Video on carbon sequestration in Oman ophiolite
http://www.whoi.edu/oceanus/viewArticle.do?id=61206 (from one of the Skepchicks)
Callan Bentley
Suevite from Vrederfort
One of my students brought this sample in the other day: She said her father collected it in South Africa. It was labeled “suevite.” I learned the term suevite about a year ago, while touring the USGS Chesapeake Bay Impact Crater coring project samples at the USGS Headquarters in Reston, Virginia. Wright Horton taught me … Read more
Rusty weathering rind
On a granite block
Giant ground sloths
In the American Museum of Natural History: These mylodontids reminded me of Puerto Natales…
Where I am today
Graphics by USGS, after Schuberth, 1967.
Travertine nubbins on a bridge
Another in the Geology Of Central Park series…
Plumose structure
Propagation direction: upper left towards lower right:
Erratic
!!!
Glacial striations, southern Central Park
New York City has some cool geology: Paleozoic metamorphics scraped by Pleistocene glaciers.
Differential weathering in the Manhattan Schist
S.E. Central Park:
Glittery!
The Manhattan Schist with its well-developed alignment of muscovite mica:
Three small faults
Live geoblogging from the line waiting to get into a museum exhibit…
The Ghosts of Evolution, by Connie Barlow
Over Snowmageddon, I read Connie Barlow’s book The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms. [Google Books; Amazon] Barlow isn’t a scientist, but she’s got a scientist in her pocket: Paul Martin of the University of Arizona. In 1982, Martin and Dan Janzen of the University of Pennsylvania published a paper … 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
Quote du jour
“Strive to interpret what really exists.” -Louis Agassiz
Triassic rifting in the Capitol
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
Advice for giving a talk
What makes a good presentation? I watch a lot of talks. Between monthly meeting of the Geological Society of Washington and professional meetings and student presentations and local departmental seminars, I see a lot of people present information aloud, with varying degrees of success. I also give talks. While I don’t claim to be the … Read more
Crucifix site 3: a WTFite
So, I’ve introduced you to the sediments at the Crucifix Site, and the faults which cut across those sediments. Today, I would like to show you something else that I found there, and ask you to tell me just what the hell it is. Here we go: an outcrop of the volcaniclastic sediments in this … Read more
Crucifix site 2: Horsts & grabens
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
Crucifix Site 1: Sediments
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