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Looks like I’m late to the party… While I was away, apparently the geoblogosphere went on a rampage of cooling columns. Everyone was posting images of their favorite columnar joints, and I was left out in the cold. Let me remedy that now. As it turns out, I was visiting some columns while everyone else [...]
Filed under: basalt, conferences, igneous, joints, structure, travel, turkey | 1 Comment »
As mentioned, I spent a significant part of last weekend was spent on a paleomagnetic sampling project with collaborators from the University of Michigan. On Friday, this was our field area: That’s the south slopes of Old Rag Mountain, a popular Blue Ridge hiking destination because unlike many Virginia peaks, when you get to the [...]
Filed under: basalt, blue ridge, geology, granite, igneous, joints, mesoproterozoic, mountains, national parks, neoproterozoic, paleomagnetism, proterozoic, virginia | 9 Comments »
Whilst hiking at Dolly Sods over the weekend, I found this old artifact: Upper 10 is apparently a “Sprite”-esque lemon-lime soda, discontinued in America but still being marketed abroad. But that wasn’t what got me jazzed, of course. Look more closely… That is a lovely little conchoidal fracture, and it’s so exquisite because it preserves [...]
Filed under: analogies, joints, structure | 5 Comments »
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 [...]
Filed under: asia, cretaceous, geology, himalayas, joints, mongolia, montana, north america, rockies, russia, sandstone, structure | Comments Off
Tension gashes are small veins that open up when rocks get stretched. Often, they are arrayed en echelon with respect to other tension gashes, all oriented in the same direction. Here is a sample of tension gashes I found this summer in rip-rap (i.e., not in situ) at some building site in New England. (I [...]
Filed under: faults, folds, geology, joints, quartz, structure | 7 Comments »
After my thesis defense at the University of Maryland, my mentor and friend E-an Zen asked me if I had ever heard of the Purgatory Conglomerate. I had not. Over the years, E-an has been a great source of new ideas and information to me, and so when he raises a notion, I pay attention. [...]
Filed under: glacial landforms, joints, rhode island, sediment, structure | 6 Comments »
In my previous post, I introduced you to the Petersburg Granite, as it is exposed south of Belle Isle, at the falls of the James River in Richmond, Virginia. I mentioned that it was fractured, and I’d like to take a closer look at those fractures today. The geologically-imparted fractures were exploited by human granite [...]
Filed under: faults, geology, granite, joints, piedmont, structure, virginia | Comments Off
Last Friday, NOVA colleague Victor Zabielski and I traveled down to Richmond, Virginia, to meet up with Chuck Bailey of the College of William & Mary, and do a little field work on the rocks exposed by the James River. Our destination was Belle Isle, a whaleback-shaped island where granite has been quarried for dimension [...]
Filed under: boudinage, building stone, coastal plain, geology, granite, igneous, joints, mississippian (carboniferous), piedmont, rivers, virginia, xenoliths | 4 Comments »
Today, you get a photo from GMU structure student Nik D. This is a small exposure in the Hampshire Formation (Devonian) on New Route 55 in West Virginia. It shows a fine example of plumose structure with the not-often-seen concentric ribs running perpendicular to the ‘plumes.’ At the edge of the joint, you can see [...]
Filed under: devonian, joints, structure, valley and ridge, west virginia | Comments Off
