Friday fold: Difficult Run fun
The Friday fold takes us to some high-grade metamorphic rocks in the Piedmont of northern Virginia.
granite
The Konnarock Formation
A detailed description of one of the Virginia Blue Ridge’s most intriguing geologic formations: a maroon sedimentary sequence showing the advance of “Snowball Earth” glaciers in the Neoproterozoic.
Geology of the Richmond area field trip
On Saturday, after a fruitful 24 hours at the VCCS Science Peer Conference, my colleague Pete Berquist (of Thomas Nelson Community College) and I led a field trip to examine the geology of the Richmond, Virginia, area. We were joined by seven of our VCCS science-teaching colleagues and author Lisa Starr, a speaker at the … Read more
Drilling: what, why, and how
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 … Read more
Falls of the James II: fractures
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 … Read more
Falls of the James I: pluton emplacement
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 … Read more
Easter egg
Searching through my photo archives this morning for something suitably “Eastery”… something in pastel colors, perhaps? … a petrified lagomorph? … how about an egg, or something egg-shaped? This is as close as I got: This is in the Owens Valley of eastern California, showing a boulder of the Mesozoic Sierra Nevada Batholith bearing a … Read more
Folds of New York
Thursday is ‘fold day’ here at Mountain Beltway. Let’s take a look at some folds I saw last weekend in New York City. We’ll start with a bunch seen in the Manhattan Schist in Central Park. Here’s an example of the foliation in the schist. It’s got finer-grained regions and coarser, schistier regions with big … Read more
Rusty weathering rind
On a granite block
Piedmont rocks exposed in a creek
One of the cool things about being the local geoblogger is that people get in touch with you about local geology. Sometimes this even leads to meeting up for field trips. Here’s two quick photos from a recent (January 2010) field trip to a creek near Springfield, Virginia. My host was Barbara X, a local … Read more
Plutonic contacts in eastern Sierras
Last September, at the location of the faulted moraine (eastern Sierra Nevada, California), I took some photos of some of the sexier plutonic contacts exposed in big boulders (erratics) of the glacial till composing the moraine. Check them out. What do you see here?
Dalmatian pluton
Continuing with some photos from eastern California… After checking out the faulted moraine, but before heading up the hill to check out the indurated shear zone (which you can just see in the background of this photo), we stopped to check out this visually-striking outcrop: Look at the glee on the faces of Kurt (green … Read more
A small shear zone
Back at NOVA Geoblog, I spent a portion of September and October 2009 reviewing the geological wonders I witnessed as part of a GSA field forum in the Owens Valley of California. However, I got distracted by other things, and never finished the series. I’d like to pick up on that today, looking at a … Read more