You are browsing the archive for ordovician Archives - Page 4 of 5 - Mountain Beltway.
2 January 2013
Upturned Paleozoic strata on Highway 16, Bighorns, Wyoming
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 tad, looking north), consider this GigaPan I shot at the time: link The best part …
21 November 2012
Rock Cycle I: Sedimentary → Metamorphic
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.
18 November 2012
Another batch of GigaPans from the M.A.G.I.C. project
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
3 August 2012
Friday fold: lower Martinsburg Formation near Bixler’s Ferry
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!
17 June 2012
Massanutten sketch
A sketch of the Massanutten Synclinorium is presented, made with a Wacom Cintiq stylus/monitor combination.
27 April 2012
Friday fold: Nashoba migmatite
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
16 February 2012
Wyler Aerial Tramway and the Franklin Mountains of West Texas
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.
2 August 2011
Receptaculid at Medicine Wheel
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).
26 May 2011
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: 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 the word “Gigapan” in the lower right.
21 March 2011
The Big Bentonite just got smaller
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 sedimentation with the deposition of the Helderberg Group of limestones, and then more active margin …
Callan Bentley is Associate Professor of Geology at Piedmont Virginia Community College in Charlottesville, Virginia. He is a Fellow of the Geological Society of America. For his work on this blog, the National Association of Geoscience Teachers recognized him with the James Shea Award. He has also won the Outstanding Faculty Award from the State Council on Higher Education in Virginia, and the Biggs Award for Excellence in Geoscience Teaching from the Geoscience Education Division of the Geological Society of America. In previous years, Callan served as a contributing editor at EARTH magazine, President of the Geological Society of Washington and President the Geo2YC division of NAGT.