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11 August 2017
For the Friday fold, Callan digs out images of Eagle Rock, Virginia, well aged in his digital archive for a decade!
1 June 2017
Ahhhh, a raw Scottish coast. …Let’s go there. There’s sedimentology to be learned here, and coastal geomorphology to be ogled. This is Yesnaby, on the west side of Orkney. The rocks there are part of “the Old Red Sandstone,” a neat package of Devonian strata, flavored here and there with an igneous dike, a fault, etc. But overall, I’d like to focus on the strata. The strata I saw at …
9 May 2017
The Foreknobs Formation is a Devonian unit in the Valley & Ridge province of the Mid-Atlantic Region. It was deposited in relatively shallow near-shore conditions during the Acadian Orogeny. On a field trip to Corridor H, a new highway transecting the West Virginian Valley & Ridge province on Monday, I stopped to document a couple of beds showing very nice ripple marks. These ones are symmetrical, and thus likely represent …
2 March 2017
On the northwestern coast of the Northmavine Peninsula of Shetland, there is an unusual coastal landform: a gate-like entrance to an elevated amphitheater, like something out of Tolkien, and a storm beach of slab-like boulders inland of that.
27 February 2017
A new outcrop in Fort Valley shows Devonian fossil-rich mudrocks overprinted by a tectonic cleavage imparted during Pangaea’s birth throes.
25 February 2017
Some enormous concretions are encountered in a shale quarry in the central Fort Valley. Concretions like these are typical of the Devonian-aged Millboro Formation.
1 February 2017
In eastern Shetland, the sea chews away at the innards of a Devonian stratovolcano. But there’s an odd visitor there too – and we’re not talking about the blogger.
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. …
27 June 2016
Dunbar, Scotland, is a nice little seaside town that also happens to be the birthplace of the conservationist John Muir. My family and I have been based out of here this week on our European geological GigaPan expedition. But on our first morning, upon visiting Siccar Point (which is nearby), I threw out my back, and spent most of the next two days recuperating. I did manage a short walk …
20 June 2016
Want a geological irony? Here’s one! You’re looking at a rounded boulder of Cushendun Conglomerate, a Devonian “Old Red Sandstone” unit (Cross Slieve Group) exposed at Cushendun Caves, Northern Ireland, U.K. The irony lies in the repetition of history – a tumbling environment of high water energy, rounding cobbles and boulders and depositing them, in order to make the conglomerate. And now, ~400 million years later, history repeats itself, with …