Here’s a terrific outcrop to start off the new year at Mountain Beltway. We’re back in the Bighorns of Wyoming here, on highway 16, traversing the southern portion of the range en route from Buffalo to South Pass City. Click to enlarge Annotated, expanded, and Easter-egg-embedded: Click to enlarge From a different perspective (uphill a … Read more
An outcrop of the Ordovician-aged Martinsburg Formation is used to illustrate the development of slaty cleavage, and hence a major transition in the Rock Cycle.
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: [gigapan id=”118645″] link [gigapan id=”115600″] link [gigapan id=”118644″] link [gigapan id=”115165″] link [gigapan id=”114737″] link [gigapan id=”118648″] link [gigapan id=”114939″] link
The Friday fold is presented in photo, annotated photo, and GigaPan formats. It’s a cleaved anticline in lower Martinsburg Formation limy slate from Page County, Virginia. See if you can spot Mr. E. coli in the GigaPan!
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
Riding a cable-car up the side of the Franklin Mountains, Callan checks out the local stratigraphy and structure (and igneous intrusions). Join him on an insightful cruise up several thousand feet and through a billion years of geologic time.
On the way to visit the Bighorn Medicine Wheel, in a road-bottom outcrop of the Bighorn Dolomite (Ordovician), Callan finds a lovely receptaculid fossil (colloquially known as a “sunflower coral,” though it’s not a coral at all).
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 Shenandoah Valley of western Virginia records the switch in late Ordovician time from passive margin sedimentation associated with the Sauk and Tippecanoe epeiric seas, to active margin sedimentation associated with the onset of the Taconian Orogeny to the east. Higher up in the stack, a similar pattern is seen: a return to passive margin … Read more