I went on a day of field work last week to Corridor H, West Virginia, to help make drone-based photogrammetric 3D models of the huge outcrops there. One site we stopped at is this beautiful V-shaped syncline in Devonian-aged Helderberg Group limestones. Click to enlarge Here are two layers traced out: Here is a GigaPan … Read more
Some web research led to a serendipitous discovery and further exploration. Wherever you’re sheltering in place, you don’t have a view that’s this grand. Slip away for a few moments to the high country of Montana’s Glacier National Park, where an anticline may be seen in the towering cliffs…
This is such a gorgeous map: Link 0.43 Gpx GigaPan of a geologic map by Berg, T.M., Edmunds, W.E., Geyer, A.R., Glover, A.D., Hoskins, D.M., MacLachlan, D.B., Root, S.I., Sevon, W.D., and Socolow, A.A., (1980) I’ve been organizing a bunch of geologic maps this week for my Historical Geology students, and this is one of … Read more
What day is it again? Hard to keep track in the days of raging coronavirus infections, but it is in fact Friday, which means that if you want a dose of the halcyon pre-COVID-19 days, you can enjoy this example of a false fold from Death Valley National Park’s Titus Canyon.
The Friday fold shows disharmonic crumpling in marbles of the Boyden Cave Root Pendant in California’s Sierra Nevada. The GigaPan image displayed is part of the digital legacy of Ron Schott, who passed away a year and a half ago.
The Friday fold erupted out of a volcano, completing the second part of its two stage cooling history, then later got folded and metamorphosed. It was found atop a high cliff near the northern Newfoundland town of St. Anthony.
A virtual field trip to examine some deepwater clastic sediments shed off the first phase of Appalachian mountain building, and deformed in the third phase. It’s a lovely day for a field trip to the late Ordovician!
We saw last week how glaciation carved out a valley in Scotland called Glen Roy. As the glacier ground into the landscape, it liberated tremendous numbers of sedimentary particles from the bedrock, which is composed of Dalradian metamorphic rocks (mainly porphyroblastic schist in my observation). Then once that now-U-shaped valley had been deglaciated, a new … Read more
A reader asks: “What is foliation and what makes it so important to the structure of rock?”
Callan answers with a lot of images of beautifully foliated rocks.
Cross-bedding isn’t just for modern sedimentary deposits; you can find it in truly ancient ash deposits too! Let’s head to South Africa and take a look.
A visual challenge via Twitter to determine stratigraphic younging direction ends with equivocal results. So let’s use GIGAmacro imagery to school your sedimentological students on how three primary sedimentary structures look different right-side-up versus up-side-down.
A solo hike in search of anticlines yields new outcrops and good views!
Last week, I was in Morgantown, West Virginia, to deliver a colloquium talk to the geology department at West Virginia University of geological visualization. The next day, I took some time on the way home to geologize a bit on the road called Corridor H, a gorgeous transect through the eastern Allegheny Plateau and western … Read more
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 Friday folds are small soft-sediment deformational features within a dismembered, folded sandstone (a “ploudin”) from a mass transport deposit from the latest Devonian of West Virginia.
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.
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!