Lawhorne Mill High Strain Zone
Callan attends a field trip in the Blue Ridge of Virginia, looking first at a Paleozoic shear zone that disrupts (and improves) Mesoproterozoic basement complex rocks.
virginia
Portrait of a cricket
Spied this lovely cricket while hiking the White Oak Canyon Trail in Shenandoah National Park yesterday: I realize there’s been a pretty high bugs : rocks ratio on Mountain Beltway of late; I’m just in summer mode, I reckon. And Virginia’s arthropod profligacy keeps bringing me into contact with these extraordinary segmented denizens of the … Read more
The grave of John Wesley Powell
Callan visits the grave of John Wesley Powell, second director of the USGS and explorer of the Grand Canyon, on an afternoon in Arlington National Cemetery.
Friday fold(s): the Outdoor Lab
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
Tumbling Run: New Market/Lincolnshire contact
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: [gigapan id=”78234″] 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 … Read more
The view from Signal Knob
Here’s a gigapan I shot last Saturday, looking north from Signal Knob, Virginia: [gigapan id=”77989″] As usual, you can see it full screen, by clicking on the word “Gigapan” in the lower right.
Fault in Massanutten Sandstone
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. [gigapan id=”78209″] Unfortunately, the auto-stitch deformed my face. I look like Quasimodo. Oh well. As usual, you can see … Read more
A tidy little quartz crystal
A doubly-terminated quartz crystal (or “Herkimer diamond”) is found on a hike in the Silurian sandstones of Virginia’s Valley & Ridge province.
New hallway display: geologic provinces of northern Virginia
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).
Some cool rocks from DGMR’s rock garden
A brief tour of some cool rocks, shown in close-up, from the rock garden at the Commonwealth of Virginia’s Department of Geology and Mineral Resources in Charlottesville, Virginia, presented as a follow-on to the gigapan of the garden shown a month ago. The post features close-ups of plumose structure in slate, epidote slickensides, and graded bedding in ancient rhythmites.