You are browsing the archive for silurian.
13 November 2020
A quick “Friday fold” that is expressed in three dimensions – “stairstep” style folds deforming a bed of Tonoloway Formation dolostone…
8 May 2020
Eric Fulmer (who pitched in with last week’s Friday fold) returns this week with another treasure. He writes, I was in Hopeville, WV a couple of years ago. The entire area between Cabins and Hopeville is a real joy (geologically and recreationally) as some of the most resistant rocks of the Mid-Atlantic Appalachians are folded and exposed in quick succession and with great relief. I am particularly fond of seeing …
1 May 2020
Reader Eric Fulmer has contributed a fold as a balm for the end of another week of COVID-19 self-quarantine. Check it out: Eric writes, I was in Hopeville, WV a couple of years ago. The entire area between Cabins and Hopeville is a real joy (geologically and recreationally) as some of the most resistant rocks of the Mid-Atlantic Appalachians are folded and exposed in quick succession and with great relief. …
23 January 2018
On a family hike, Callan’s son finds some interesting smooth lines on a rock. What are they? What do they tell us? Tune in for a brief history of Appalachian geology.
11 August 2017
For the Friday fold, Callan digs out images of Eagle Rock, Virginia, well aged in his digital archive for a decade!
23 May 2017
Journey to the Silurian period in what is today the Valley & Ridge province of eastern West Virginia to see some exquisite sedimentary rocks that represent deposition in a very arid, very shallow setting.
30 June 2016
Time for another virtual field trip on the Geologist’s Grand Tour of the United Kingdom: the most famous outcrop in the world. Today, we visit Siccar Point, Scotland. You’ve probably already seen photos of this place – they usually look something like this: To those who aren’t familiar, here’s what going on: There are two sets of strata here – and the contact between them is an ancient erosional surface. …
9 June 2016
Our series of virtual samples continues! This week, I’m presenting examples of a visualization combination that leverages the advantages of the GIGAmacro system with the 3D ‘virtual sample’ perspective of the Sketchfab-hosted model: the same sample presented in both formats. Today, we feature a lovely slab of limestone, chock full of fossil material, and showing both primary sedimentary structures like graded bedding and cavity fills (both geopetal indicators), but also …
16 May 2016
Over the weekend, my wife and I took a walk with our son at the Storybrook Trail, an accessible trail with a fine overlook to the east over the Page Valley. There, the Massanutten Sandstone shows a bunch of big beefy trace fossils at this site: both bedding-parallel (Arthophycus-like) and bedding-perpendicular (Skolithos-like) traces. Here’s Bax on a photogenic slab of the quartz arenite, showing the inch-wide bioturbation: A short distance …
2 May 2016
More 3D models: digital facsimiles of real rock samples. Check them out and explore! Clinker from the Powder River Basin, Wyoming: Ripple marks from the Rose Hill Formation, West Virginia: Meta-komatiite from the Red Lake Greenstone Belt, northern Ontario, Canada: