Callan Bentley A week ago today, I was in Tempe, Arizona, at Arizona State University, for a workshop on broadening participation (increasing diversity) in the geosciences. One of the neat things about ASU as a setting for this meeting is their enormous meteorite collection. I was particularly taken with the display of material from the extraordinary Chelyabinsk … Read more
We visited the Philip Carter Winery this weekend with family. Baxter and I were pleased to see outcrops of charnockite scattered over the property (located in the middle of the Blue Ridge geologic province). As any 18-month-old will tell you, charnockite is a pyroxene-bearing granitoid. It’s a distinctive and common rock type in Virginia’s Proterozoic … Read more
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, … Read more
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 … Read more
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 … Read more
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 … Read more
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.
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, … Read more
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 … Read more
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 … Read more
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.
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 … Read more
Scott Johnson contributed this special “Valentine’s Day” edition of the Friday fold: a lovely primary igneous structure that evokes a heart: That’s a close-up view (lens cap for scale) that Scott took when he GigaPanned this feature: link … the big obsidian flow at Newberry Crater in Oregon. That’s a really dry lava flow that … Read more
At the eroded gully known as Devil’s Coulee in Alberta, you can find armored mudballs, dinosaur fossils (including eggshell), and even marine clams at higher levels in the sequence. Check out these lovely beasts: They lived and died on the western shore of the Western Interior Seaway during the Cretaceous period of geologic time. My … Read more
When Michael Collier came to visit last year, he recommended a couple of books to me. I finally got around to reading the first of them – Refuge, a memoir mixed with natural history of Utah by Terry Tempest Williams. The arc of the story is essentially twofold: the women in Williams’ family get cancer, … Read more
I ran out of folds last December, I asked for help on Twitter. Laura Hamilton was among the first to respond, with a link to this image: @callanbentley Hartland Quay, Devon UK. Huuuuge chevron folds! pic.twitter.com/7bhRfLib9Y — lau.rah (@hammijam) December 23, 2013 Thanks, Laura, for another great image!
Callan reviews Bob Hazen’s latest book, “The Story of Earth,” a history of our planet that emphasizes the coevolution of minerals and life.
This past week, there’s been a beautiful sight along the stretch of the Fort Valley Road that goes past the Blue Hole section of Passage Creek. Click to enlarge Ice has been forming beautiful forms as groundwater seeps out along bedding planes in the Massanutten Sandstone (a Silurian-aged quartz arenite, folded during late Paleozoic Alleghanian … Read more
Todd Redding is our genorous sponsor for this week’s Friday fold. Todd reports that this boulder is derived from the Okanagan Metamorphic Complex near Penticton, British Columbia, Canada. He gives its lat/long as 49°28’14.10″N, 119°30’23.14″W. Did you spot the small fault in there, too? Thanks for sharing, Todd!
One of the intriguing rocks you find in Virginia, at the interface between the Valley and Ridge province and the Blue Ridge province, is distinctive brecciated Antietam Formation. The Antietam (sometimes known as the “Erwin,” especially in Shenandoah National Park), is a quartz arenite (quartz sandstone) that has been variably fused to quartzite in some … Read more