Callan unveils a collection of 56 super-high-resolution images showcasing various principles of relative dating, aimed at a general education audience like undergraduate Historical Geology. He also offers a suggested lesson plan structure for instructors wishing to utilize the images.
I love the idea of high-resolution imagery that users can explore for geological meaning from the comfort of their computer screens, tablets, or phones. I think that 3D models and gigapixel-resolution panoramas (GigaPans) are powerful media for connecting people with the Earth. They allow improved access for many populations. Long-time readers will report that I … Read more
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 … Read more
Near the southern end of Lake Mývatn, astride the Mid-Atlantic Rift in northern Iceland, lies a field of “pseudocraters” that result from steam explosions beneath a fresh lava flow. Put on your head-net and join us to check it out!
The evidence for a meteorite impact origin for the Stoer Group’s Stac Fada member seems to stack up. Engage in a virtual field investigation on Mountain Beltway.
Do you remember the blog post four years ago about documenting the doomed outcrops at Scientists’ Cliffs, Maryland? It was the site of gorgeous Miocene fossil exposures in the Calvert Formation. Here’s what the site looks like now: Photo by Peter Vogt That ugly thing at the base of the cliff is a gabion, … Read more
Today, let’s journey to Iceland, to a bit northwest of Reykjavík. This is a view from the top of the Grábrók cinder cone, across the valley to the east. With very few exceptions, Iceland is a big pile of basalt, and that shows through in the walls of this valley, which display a stack of … Read more
A quest to visit the “first shear zones” described in the scientific literature leads to an alternate location, and some GIGAmacro images of samples from the real, original spot.
On the western coast of Islay, Saligo Bay showcases turbidites of the Neoproterozoic Colonsay Group. The Smaull Graywacke shows Caledonian (late Ordovician) folding and cleavage superimposed on world-class graded bedding. There’s also a nice dolerite dike to examine.
As noted previously, my colleague Declan De Paor recently retired from Old Dominion University, and I was lucky enough to inherit some of his rock samples. I’ve been making super-high resolution images of the samples ever since. Here’s a particularly striking fold, weathered out differentially. Enjoy exploring it – and have a happy final Friday … Read more
Two very different samples tell stories that are full of holes. What’s going on with this weathered sandstone? What’s going on with this fossil scallop shell?
The Port Askaig Tillite is a Neoproterozoic diamictite on the eastern shore of Islay (Scotland) that may record a “Snowball Earth” glaciation.
At the birthplace of the term “mylonite,” we can find Friday folds hidden in the foliation.
Now that we’ve examined the geology of the outcrops at Funzie Bay on the island of Fetlar in northeast Shetland, let’s stroll along two beaches. Here we have cobbles from Funzie Beach and a small beach eroded from serpentenite and metaharzburgite of the island’s ophiolite complex. Compare. Contrast. Rejoice. Link GigaPan by Callan Bentley Link … Read more
Funzie Bay in eastern Fetlar, Shetland, is the place with a stretched-pebble metaconglomerate that triggered the development of the Flinn Diagram. Join Callan on a pilgrimage of structural geology to this special place.
What does the sedimentary record of a giant meteorite impact look like? Turns out it is full of tsunami breccia, fine ash, hail-like spherules, and a barium-rich ocean’s crystal precipitates. Join us in the Barberton Greenstone Belt of South Africa to learn more.
Erik Klemetti posted today at Eruptions about komatiite, which is apropos, considering I just finished imaging some samples of that ultramafic volcanic rock. Have a look at three samples from Barberton Greenstone Belt here, each from the 3.27 Ga Weltevreden Formation: Link GigaPan by Callan Bentley Link GigaPan by Callan Bentley Link GigaPan by Callan … Read more
Iceland does basalt really, really well. But there are a few non-basaltic igneous rocks to be found there, too. One of them is a green ignimbrite (pyroclastic conglomerate) that crops out in coastal Berufjörður, eastern Iceland. Check it out!
Rathlin Island lies north of mainland Northern Ireland, a few miles offshore. I spent three lovely days there this past summer, investigating the geology and appreciating the wildlife (puffins and other sea birds, and seals). The geology is pretty straightforward: Paleogene basalt overlying Cretaceous “chalk” (really not so chalky here – technically, it’s the Ulster … Read more