Back in 2011, when we were still living in D.C., Lily and I made a hiking trip out to Buzzard Rocks. It was a destination. Now that I live out here in the Fort Valley, I see Buzzard Rocks all the time, and I love it. It’s such a cool feature – a spot on … Read more
Last Saturday was the Geological Society of Washington’s fall field trip. Dan Doctor, Alan Pitts, and I led a team of ~20 geologists out to the great new exposures along Corridor H in West Virginia. Here’s the team in front of some of the parasitic anticlines and synclines that decorate the larger structure of the … Read more
Silurian aged mud cracks feature small lensoidal features: are they casts of ancient gypsum crystals?
Spotted these cross-sectioned mudcracks yesterday on Corridor H, on the GSW fall field trip: They are in the Tonoloway Formation, a batch of tidal flat carbonates with lots of evidence of shallow arid conditions.
What can a little squiggle in a rock tell us? Stylolites in West Virginian limestone cut across the bedding plane, implying Alleghanian tectonic stresses.
Pemaquid Point, Maine, is a locally-owned and -managed park near an old lighthouse. I went there yesterday with my family. We’re on vacation in coastal Maine for a week. At Pemaquid Point, the action of waves have cleaned the rocks, and they offer a delightful three-dimensional look at Acadian-aged metamorphics and granite pegmatite dikes, with … Read more
My favorite rocks are those that tell multiple stories – rocks that are “palimpsest” with subsequent “chapters” of their biography capable of being teased out, based on different features to be observed in the rock. Click to enlarge What can we see in this small sample of the Silurian-aged Tonoloway limestone, from Corridor H, West … Read more
Here’s something fun: Click to enlarge Those strata are Silurian-aged Tonoloway Formation carbonates. There are plenty of dessication cracks to be seen, as well as salt casts, among the layers exposed. But more eye-catching at this distance is the faulting that disrupts the high-contrast layers… Both (apparent) normal and reverse faults can be seen in … 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.
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
As soon as I got back from GSA, I had to run two field trips, back to back. Both are the same trip: my Historical Geology field trip to the Massanutten Synclinorium. Here’s yesterday’s crew perched on a moderately-dipping slab of Massanutten Sandstone along Passage Creek: Today, it’s the same routine all over again, though … Read more
The work of team M.A.G.I.C. continues. This is a lovely sample quartet of salt cast samples from Silurian-aged Tonoloway Formation limestone. I collected these samples on Corridor H’s newly-opened section west of Moorefield, West Virginia, last spring. The big one at the bottom was collected by my friend Leigh Henry, who graciously loaned it to … Read more
Today, two GigaPans shot of the uppermost Martinsburg Formation, informally known as the “Cub Sandstone” since it crops out along Cub Run in the southern part of the Massanutten range. 10 or 15 meters upsection (west) of these two outcrops is the base of the Silurian-aged Massanutten Sandstone, the ridge-forming unit. Lower in the section: … Read more
Yesterday, I worked on my sabbatical project, the Mid-Atlantic Geo-Image Collection (M.A.G.I.C.). Whether I go outside on a given day to shoot GigaPans of local geology depends on multiple factors: (a) How’s the weather? (b) Do I have to watch Baxter? (c) Can I bring Baxter with me? (d) How are the lighting conditions? Yesterday … Read more
My students Alan Pitts, Chris Johnson, Robin Rohrback and I have been busy adding to the Mid-Atlantic Geo-Image Collection. Check out a few of these new GigaPan images: link link link link link link link
Last Thursday, I shot a few GigaPans of moderately-dipping quartz sandstone layers (the Silurian-aged Massanutten Formation) in the creek a few miles from my house. All four GigaPans are at popular local swimming holes. The first three are from Red Hole, and the last one is from Blue Hole. Check them out: link link link … Read more
A sketch of the Massanutten Synclinorium is presented, made with a Wacom Cintiq stylus/monitor combination.
The Friday fold is a contribution from the Massachusetts Geological Survey. It shows a migmatite with lovely structure. An upcoming (free) field trip to this location will be part of the 2012 Structural Geology and Tectonics Forum: an event readers may be interested in attending
GigaPan by Alan Pitts, as part of the M.A.G.I.C. project that we are working on. Here’s another one from a few meters away. Here’s a shot from 2.5 minutes after Alan saw this anticline for the first time. Here’s some shots of my own early visit to the site, after I first found it.