Today, two examples of outcrops that reveal an overprinting relationship between metamorphic cleavage and sedimentary bedding. Both are Devonian in depositional age, from the new stretch of New Route 55 in West Virginia, west of Moorefield. The first is from limestones of the Helderberg Group, and the second is from shale of the Brallier Formation. … Read more
Nice straight-limbed syncline in the Helderberg Group of West Virginia (Devonian limestones, mainly): Alan Pitts shot a sweet GigaPan of this outcrop which you can explore here, or you can just look at this zoomed-in detail: Aaron Barth is down there in the lower right corner for scale.
More evidence of currents in the Devonian deep… Primary structures that give us clues, preserved in a place where preservation over 360 million years isn’t necessarily guaranteed. As you might expect, this turbidity currents roared in from the east, where the mountains were rising, and generating a fair bit of sand and mud, during the … Read more
Last weekend, my wife and I joined friends for a weekend of cross-country skiing in the wonderful Canaan Valley of West Virginia. On the way back, between the towns of Burlington and Romney, West Virginia, I saw this folded shale on the north side of Route 50: You can click on that panorama to make … Read more
The Friday fold is found on a newly-opened section of road in West Virginia. Join Callan in checking out some synclines and associated faults in the Devonian-aged Brallier Formation.
This blog has been noticeably photo deficient lately! Time to remedy that. Today, I offer you a couple of shots of the Brallier Formation (shale / fine-grained sandstone) in West Virginia’s Valley & Ridge province, a few miles northwest of Moorefield, on the newly-opened section of New Route 55. The Brallier was deposited in a … Read more
Callan and three students visit a world-class outcrop of columnar jointing in Shenandoah National Park.
Today’s fold is an anticline and its neighboring syncline, both exposed along a newly-opened stretch of New Route 55, west of Moorefield, West Virginia. The new Route 55 is a classic porkbarrel boondoggle courtesy of the late Senator Robert Byrd, but doggone if it didn’t open up some lovely new roadcuts. Here’s a stitched image … Read more
Some fall photographs from 2007, taken of the south fork of the Shenandoah River, southeast of Massanutten Mountain, in Virginia’s Valley & Ridge province. Photos are by my NOVA colleague, the biologist (and pilot) Mike Peglar: Our leaves are changing color now, and I’d imagine if we were soaring over the Shenandoah Valley this morning, … Read more
The Friday fold is a guest photo by James Edward Bailey, a 5th grade student from Reston, Virginia. It is the anticline shown is known as “the Devil’s Backbone,” located near Marlinton, West Virginia, right on the boundary between the Valley & Ridge province and the Appalachian Plateaus. It clearly shows differential weathering of weaker layers and tougher layers. …Also some lovely fall colors!
Last spring, I made two visits, six days apart, to Veach Gap, a small water gap superimposed on the Massanutten Synclinorium. One was with my Field Studies in Geology one-day field course, and the second was with my Structural Geology students from George Mason University. We go there to see some lovely parasitic anticlines that … Read more
By local prodigy Hannah Holland, elementary school student: Click through to make it bigger and see some details. Nice work, Hannah! Very impressive, and thanks for sharing!
Fellow geobloggers Brian and Eric have been getting all flutey on us lately, so I figure it’s a good time to show my best photo of flute casts: As the annotated copy suggests, this was taken on the side of the Pennsylvania Turnpike back in March 2008, when four Honors students and I drove up … Read more
Today’s Friday fold takes me back 25 years, to when I visited the Outdoor Lab with my science class in Arlington County Public Schools. I revisited this exemplary outdoor education facility on Tuesday, at the invitation of its director, Neil Heinekamp. Neil wanted a geology “expert” to take a look at their rocks, and I … Read more
Here’s a gigapan I shot yesterday, looking north at the contact between the New Market and Lincolnshire Formations at the classic “Tumbling Run” outcrop south of Strasburg, Virginia: See if you can find the E. coli plush toy I included, or the cm-scale pencil! As usual, you can see it full screen, by clicking on … Read more
Here’s a gigapan I shot last Saturday, looking north from Signal Knob, Virginia: As usual, you can see it full screen, by clicking on the word “Gigapan” in the lower right.
Here’s a gigapan I shot last yesterday, looking west from “Blue Hole” towards a cliff of Massanutten Formation sandstone, south of Waterlick, Virginia. A prominent fault zone can be seen in the center of the image. Unfortunately, the auto-stitch deformed my face. I look like Quasimodo. Oh well. As usual, you can see it full … Read more
A doubly-terminated quartz crystal (or “Herkimer diamond”) is found on a hike in the Silurian sandstones of Virginia’s Valley & Ridge province.
Callan shows off a new hallway display in his building at Northern Virginia Community College, showcasing the numerous geologic provinces of northern Virginia (as well as adjacent mid-Atlantic states).
If I had a structural superpower, it would be to shoot en echelon tension gash arrays from my fingertips: Photo by Sharon Ruggeiri