Callan Bentley Rust swirls on shale fragment, new New Route 55, Valley & Ridge province of West Virginia. I’m not sure if I can call this “Liesegang banding,” since it’s just on the joint surface (two-dimensional) rather than permeating the rock in a three-dimensional blob. Anyhow… It’s pretty.
Today, two examples of outcrops that reveal an overprinting relationship between metamorphic cleavage and sedimentary bedding. Both are Devonian in depositional age, from the new stretch of New Route 55 in West Virginia, west of Moorefield. The first is from limestones of the Helderberg Group, and the second is from shale of the Brallier Formation. … Read more
Nice straight-limbed syncline in the Helderberg Group of West Virginia (Devonian limestones, mainly): Alan Pitts shot a sweet GigaPan of this outcrop which you can explore here, or you can just look at this zoomed-in detail: Aaron Barth is down there in the lower right corner for scale.
More evidence of currents in the Devonian deep… Primary structures that give us clues, preserved in a place where preservation over 360 million years isn’t necessarily guaranteed. As you might expect, this turbidity currents roared in from the east, where the mountains were rising, and generating a fair bit of sand and mud, during the … Read more
We were making dinner last week and took out a block of “silken” tofu* with less care than we should have, and it broke. But what a break! The fracture showed a gorgeous elliptical joint face that broken up into a twisted series of hackles along its fringe: That’s something nice homogeneous fine-grained rocks do, … Read more
Got access to the wife’s photos from South Africa. Here are two other charismatic insects:
These are turbidites of the Malmsbury Group in South Africa, on the east shore of False Bay. A couple of nice little folds running sub-vertically through the package… Happy Friday!
Callan and his wife journey to Africa’s southernmost point, and find a geological mystery there.
Here’s where to find it, if you want to. Can’t say I recommend it – just an overlook, with no opportunities to hike or swim or explore in any more detail than just passively observing gravity exert its pull on water unencumbered by underlying rock.
After our safari, Lily and I were taken up onto the Great Escarpment in northern South Africa. The escarpment is supported by sedimentary strata of the Transvaal Supergroup that overlie the Archean basement rock of the Kaapvaal Craton. The Transvaal strata are Paleoproterozoic in age, somewhere between 2.5 and 2.0 billion years old. They are … Read more
Here’s a look at what you see if you go to the Three Rondawels viewpoint above the Blyde River Nature Reserve in northern South Africa: A lovely scene. The three mega-hoodoos on the left are the eponymous “rondawels” (pronounced ron-da-vulz), which is the Afrikaans word for a round hut. These erosional remnants are more or … Read more
Last fall, when I was out backpacking in Dolly Sods, we left one of Lily’s water bottles on the dashboard of the locked (and windows-rolled-up) Subaru. When we got back to the car, we found it had experienced heterogeneous solid-state deformation. I took a few photos, so that those of you who are interested in … Read more
With my new “macrogigapan” rig from Four Chambers Studio, I produced a single image last week as part of my Mid-Atlantic Geo-Image Collection project (M.A.G.I.C.). I’m still learning the ropes of the machine – I shot about 3 times as many photos as I needed to to make this gigapan. Lessons learned, yet again. Anyhow … Read more
Last weekend, my wife and I joined friends for a weekend of cross-country skiing in the wonderful Canaan Valley of West Virginia. On the way back, between the towns of Burlington and Romney, West Virginia, I saw this folded shale on the north side of Route 50: You can click on that panorama to make … Read more
Here’s two nice examples of mudcracks I saw used as paving stones in South Africa:
With my new “macrogigapan” rig from Four Chambers Studio, I produced these images last week as part of my Mid-Atlantic Geo-Image Collection project (M.A.G.I.C.). … Dive in! Porphyritic andesite from the Beartooth Plateau, Montana: Foliated limestone slate, location unknown: Clicking on the word “GigaPan” in the lower right corner will take you to a fuller-screen … Read more
Site of the mystery photo I posted over the weekend, the beach at Rooiels (“red grass” in Afrikaans), South Africa, is a lovely place… Located on the western side of False Bay a tad north of Cape Hangklip, Rooiels is somewhat famous in my mind because the Guru of Gigapan, Illah Nourbakhsh, spoke glowingly of … Read more
Yesterday, I showed you this picture and asked what you saw there: Today I’ll give you my impressions. This is an outcrop of sandstone of the Table Mountain Supergroup, seen on the beach in the idyllic village of Rooiels, on the eastern side of False Bay, north of Cape Hangklip, in South Africa.The field of … Read more
You can make it bigger by clicking on it.
One day in South Africa, Lily and I walked across Noordhoek Beach… Along the way, I noticed these little squiggles of sand: folded tube shapes. I decided I should photograph a few to share with Tony Martin, since he’s into trace fossils along coastal areas. Anyone have any idea what made these diminutive sculptures of … Read more