You are browsing the archive for ordovician Archives - Mountain Beltway.
25 December 2023
The Greywacke, by Nick Davidson
Just finished a geologically focused book that the readers of this blog might be interested in. It is a history of work on delineating the early part of the Phanerozoic timescale in Wales and Scotland. The majority of the book is about Adam Sedgewick and Roderick Murchison and their close collaboration and increasing divergence and eventual total estrangement as they sought to sort out the boundaries of different periods of …
16 September 2022
Friday fold: isoclinal limestone near Harrisonburg
This weekend, my family and I traveled to a little agrotainment complex north of Harrisonburg, Virginia, a joint called Back Home On The Farm. It featured a corn maze, hayrides, petting zoo, apple cider donuts, and pumpkin picking. All typical fall frolic; good clean fun. But there were also big blocks of limestone everywhere on the property. I did my best to check them all out. I was mainly scanning …
10 April 2018
An outcrop showcasing a strand of the Kentucky River Fault System
Roadcuts in Kentucky show Ordovician limestones of two distinct types, replete with fossils and primary sedimentary structures, and juxtaposed by a fault, one strand in the Kentucky River Fault System.
9 April 2018
Orthocone nautiloids of the Lexington Limestone
I took a trip last week to Kentucky. My colleague Kent Ratajeski from the University of Kentucky took me out on a nice all-day field trip to examine some of the local geology. I was particularly impressed with the large straight nautiloid fossils that abounded in the Ordovician-aged Lexington Limestone. Here are a series of photos I took of these orthocones, all on pavement exposures (horizontal bedding planes) with my …
11 August 2017
Friday fold: Eagle Rock
For the Friday fold, Callan digs out images of Eagle Rock, Virginia, well aged in his digital archive for a decade!
27 March 2017
Cleaved, boudinaged, folded Edinburg Formation southwest of Lexington
Explore a dozen photos highlighting the structural geology of an outcrop of limestone and shale near Lexington, Virginia. Cleavage refraction, overturned beds, boudinage, folds, and even a small fossil – we’ve got something for everyone. Bring the whole family!
15 March 2016
Timberville
Join Callan for a virtual field trip, as he shares dozens of photos from a recent ‘field review’ of a new geological map in Virginia’s Valley & Ridge province. Highlights: graptolites, trace fossils, geopetal structures, folds and faults.
7 October 2015
The New Market / Lincolnshire contact
Yesterday, I put a photo up here on the blog, and asked you to figure out where the formational contact was in that image. Here’s the image I showed you: It turns out that my plan to have readers upload their copies of the image didn’t work as well as I had planned – apparently you all don’t have as complete a suite of control options as I do. Shocker! …
5 October 2015
Trace fossils in the Juniata and Tuscarora Formations
Route 33 in Pendleton County, West Virginia cuts across the lower Paleozoic stratigraphic section. I went there this past spring on a sedimentology and stratigraphy field trip with the GMU sed/strat class. The trip was orchestrated by professor Rick Diecchio. Here are some scenes from two of the stops – the upper Ordovician Juniata formation (red sandstones and shale intepreted as Taconian molasse) and the overlying Silurian Tuscarora Formation (thick …
12 September 2015
New GigaPans from Team M.A.G.I.C.
Hampshire Formation outcrops on Corridor H, West Virginia: link (Marissa Dudek) link (Callan Bentley) Faults in the Tonoloway Formation, Corridor H, West Virginia: link (Marissa Dudek) Conococheague Formation, showing stromatolites and cross-bedding: link (Callan Bentley) link (Jeffrey Rollins) Tiny folds and faults, from a sample I collected somewhere, sometime… oh well, it’s cool regardless: link (Robin Rohrback) Fern fossil in Llewellyn Formation, St. Clair, Pennsylvania: link (Robin Rohrback) Cross-bedding in …
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.