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?
No time for more details than that – sorry! Happy Friday and a restful weekend to all!
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 … Read more
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.
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: … Read more
Yesterday, I worked on my sabbatical project, the Mid-Atlantic Geo-Image Collection (M.A.G.I.C.). Whether I go outside on a given day to shoot GigaPans of local geology depends on multiple factors: (a) How’s the weather? (b) Do I have to watch Baxter? (c) Can I bring Baxter with me? (d) How are the lighting conditions? Yesterday … Read more
Here are a few folds in the quartzites of the Cape Fold Belt, exposed on the mountainsides of the Harold Porter Botanical Gardens in Betty’s Bay, South Africa. Hillside #1: Zooming in closer: Annotated (bedding traced out): Hillside #2: Zooming in on summit region: Annotated (bedding traced out): Zooming in on the central portion of … Read more
Callan attends the Geological Society of Washington’s fall field trip, examining the relationship between grape-growing and the underlying geology of two provinces in northern Virginia: the Blue Ridge and the Valley & Ridge. With GSW compatriots, Callan visited Hume Vineyards in the central Blue Ridge province and North Mountain Vineyard and Winery in the Shenandoah Valley. This is part II of the field trip report.
Last Thursday, I shot a few GigaPans of moderately-dipping quartz sandstone layers (the Silurian-aged Massanutten Formation) in the creek a few miles from my house. All four GigaPans are at popular local swimming holes. The first three are from Red Hole, and the last one is from Blue Hole. Check them out: link link link … Read more
Concentric ribs with hackles on a joint face, quartzite (metamorphosed fine-grained quartz sandstone stained with hematite) from Waterton Lakes National Park, southern Alberta.
As I mentioned, Monday had me out in the field, looking at the western Blue Ridge and eastern Valley & Ridge provinces in Virginia. This was a field review for the new geologic map of the Elkton East quadrangle by Chelsea Jenkins, Chuck Bailey, Mary Cox, and Grace Dawson. Immediately after lunch, we visited an … Read more
I took my structural geology students to that fine outcrop of the Swift Run Formation in eastern Shenandoah National Park on Friday. There, we saw lovely primary structures with tectonic fabric overprinting (as I have showcased here previously). Consider this graded bed with subsequent (vertical) cleavage: And here’s the hinge of a nice passive fold, … Read more
I got this note via email last week. Hi Callan, First of all, congratulations to your blog. It is just great. I would like to contribute to your “Friday fold” section. A few words about myself. I am born in Austria and did my BSc and MSc at the Montanuniversitaet Leoben. In September 2011 I started … Read more
I collected this sample the weekend before last on the Blue Ridge Thrust Fault field trip led by Alan Pitts. It’s a chunk of the Antietam Formation quartz sandstone, a Cambrian beach deposit. The face we photographed measures 15 cm by 12 cm. link It definitely looks best in full screen mode, so please feel … Read more
My first view of Lion’s Head, the little butte northwest of Table Mountain, came through the fog on the morning that Evelyn and Jackie took Lily and I to Sea Point to see the migmatite: A lofty pinnacle – made of the same flat-lying quartz sandstone as the mesa of Table Mountain to the southeast: … Read more
Some tafoni (pattern of little weathering pits) expressed on Malmesbury Group (~700 Ma) turbidite sandstones at a little outcrop on the eastern shore of False Bay, South Africa: That last one seems to have some concentric layering to the tafoni pits – exfoliation? Spheroidal weathering? Hmm…
In December, Callan found an outcrop of Neoproterozoic-aged turbidites in South Africa, on the eastern shore of False Bay.
GigaPan by Alan Pitts, as part of the M.A.G.I.C. project that we are working on. Here’s another one from a few meters away. Here’s a shot from 2.5 minutes after Alan saw this anticline for the first time. Here’s some shots of my own early visit to the site, after I first found it.
A few scenes out the left side of the airplane from when I flew from El Paso to Houston a week and a half ago… Sand dune field overprinting desert vegetation and human roadways: Outcrop pattern of horizontal strata (tracing out the contours of this hill), and the weird geometry of human road systems: More … Read more
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.