You are browsing the archive for sandstone - Mountain Beltway.
24 October 2013
Over the summer, I shot these two GigaPans of the “Great Unconformity” in Wind River Canyon (Owl Creek Mountains), Wyoming: link link This week, Team M.A.G.I.C. (by which I mean my student Robin Rohrback-Schiavone) finished up a series of three macro GigaPans of rock samples from the site (made with our one-of-nine-in-the-world GIGAmacro rig by Four Chambers Studio): link link link In combination, these five images could be used to …
1 October 2013
I have two new GigaPans of hand samples to share with you this morning… The Edinburg Formation graptolites from Mint Spring, Virginia, that I featured here back in May, can now be explored in GIGAmacro hand sample: link Students: are these colonial or solitary organisms? Benthic, nektonic, or planktonic? Does this relate to their usefulness as index fossils? And here’s a graded bed from the Martinsburg Formation (Ordovician turbidites) exposed …
15 August 2013
Have a look at this lovely (almost glowing) example of a disconformity between Coloradan limestone and overlying sandstone.
25 April 2013
Today, let’s go back to the Pike Dam, where we spent some lovely moments last week, agog at the lovely graded beds and flame structures visible there. In contrast, today we want to examine the deformational structures seen elsewhere at this same outcrop. There are folds and faults and joints and more exotic fare: tension gashes and Riedel shears. The deformation here is the youngest to affect the Vermillion District …
23 April 2013
Two years ago, I took a trip to the Phoebe Hall Knipling Outdoor Lab, which is Arlington, Virginia’s outdoor education facility in the Pond Mountains (southern continuation of the Bull Run Mountains), on the eastern edge of the Blue Ridge geologic province. I was invited back last week to look at some new exposures. I brought the GigaPan along. There had been additional erosion on the saprolitic exposure of Harpers …
21 April 2013
Three new GigaPans I shot last Friday east of Staunton, Virginia, at a semi-legendary exposure behind the Sleep Inn at the 250 / 81 intersection. link link link Students: Which way is up? Which criteria did you use to make that determination?
5 April 2013
No time for more details than that – sorry! Happy Friday and a restful weekend to all!
2 April 2013
Are you into structure? Sedimentology? Stratigraphy? Well, I’ve got some good news for you – I’ve imaged several key outcrops on the newly-discovered (to me) roadcut on South Page Valley Road, showcasing the middle Martinsburg Formation turbidites (and their Alleghanian structural overprint). link link link link link link See if you can find: an anticline a syncline a fault a trace fossil a tool mark a graded bed cleavage refraction …
29 March 2013
The Friday fold photo was taken this morning on a GigaPanning expedition, and shows a small syncline within turbidite strata of the Martinsburg Formation, Page Valley, Virginia.
20 March 2013
Today, two GigaPans shot of the uppermost Martinsburg Formation, informally known as the “Cub Sandstone” since it crops out along Cub Run in the southern part of the Massanutten range. 10 or 15 meters upsection (west) of these two outcrops is the base of the Silurian-aged Massanutten Sandstone, the ridge-forming unit. Lower in the section: link Higher in the section: link If you explore these GigaPans, you’ll find a trend …