You are browsing the archive for 2014 February.
28 February 2014
For the Friday fold, let’s journey back to the Silurian, as exposed in the limestones of that age that were deformed during Alleghanian mountain-building (Pennsylvanian and Permian), and exposed along Corridor H in eastern West Virginia. Some buckling (cuspate-lobate form) seen in that one… A little pop-up with hinge collapse: And, finally, as a digestif, consider this little morsel: That’s a bite-sized Friday fold. Have a good weekend!
27 February 2014
Over the past 2 weeks, I’ve been sharing some images here from a field trip the previous week to Corridor H in eastern West Virginia. I love this road, but I guess it’s fair for me to point out that sometimes in the middle of winter, this is what the outcrops look like: …Yep. Next road-cut, please.
26 February 2014
More images for you today from my field trip a few weeks ago to West Virginia’s bizarro highway Corridor H, a quiet place built for roaring traffic. Its multistory roadcuts are fresh and profound; they offer the most incredible views into the mid-to-late-Paleozoic surface of Earth… and the creatures that lived there. In the Devonian period, the Helderberg Group of limestones was deposited. It’s full of interesting fossils, the remains …
25 February 2014
While on Corridor H 2 weeks ago with Alan Pitts, we stopped astride the Patterson Creek Mountain Anticline, with extensive road cuts displaying Tonoloway Formation overlying Wills Creek Formation. We love this spot for its lovely folds and halite casts. See what I mean? link link This time, however, my eye was drawn to the prodigious quantities of mudcracks to be seen in side-view (that is, in cross-section). Take a …
24 February 2014
While we’re out on Corridor H, let me show you some new halite casts I found (either the Wills Creek Formation or the Tonoloway Formation): Salt casts are among my favorite primary structures. They speak very specifically to hypersaline depositional conditions.
21 February 2014
Howard Allen, a blog reader from Canada, digitized a bunch of folds for us from his old Kodachrome slides. You’ll be seeing selections from these images over the weeks to come. Get psyched! There are some great folds in this batch. Here’s the first: Howard’s description: 3D folded marble, Shuswap Metamorphic Complex, north of Sicamous, British Columbia. Specimen was bulldozed out of the way for a logging road. Photographed in …
20 February 2014
While out on the Corridor H field trip last week before the heavy snow, I found this squeal-inducingly-lovely example of a stylolite in Helderberg Group limestones (Devonian passive margin carbonates): The stylolite is a pressure-solution surface, made especially apparent in this example because of the starkly different grain sizes and colors on either side of the dissolved-away rock: This is a gorgeous sample to explore in macro GigaPan view. Enjoy: …
19 February 2014
Today, we continue with the story of the field trip I took last week out to Corridor H, the new superhighway in West Virginia that is practically unused, and decorated with multistory roadcuts of spectacular Valley and Ridge sedimentary sequences, and their attendant structures. From the putative Hampshire Formation exposures with their uncharacteristic marine incursion strata, we moved downhill (and, down-section) to examine a road-cut of what we inferred to …
18 February 2014
See the size of those road cuts? Count all those cars? Exactly. Why this place isn’t swarming with geologists, I cannot for the life of me comprehend.
17 February 2014
I went out last Tuesday to Corridor H, the exemplary new highway cutting through the Valley and Ridge province of eastern West Virginia. Joining me was former student Alan Pitts, a devotee of Corridor H from way back in the early days when we just called it “New Route 55.” The boondoggle highway is now open all the way west to the Allegheny Front, practically into the Canaan Valley. On Tuesday, …