Martin Schmidt again contributes a fold – this time from his summer trip to South Africa: Pretty great! This is part of the Cape Fold Belt. Perhaps some of you will drive by it when you go to the International Geological Congress in South Africa later this month! You can view the site in the … Read more
Pahoehoe “ropes” on a basalt, sample site unknown: Archean gneiss from the Gallatin Range of Montana: Tafoni in Malmesbury Group turbidites, South Africa:
The Friday fold is a trio of hand samples of folded banded iron formation from South Africa. Collected in 2012 as float from the “contorted bed” outcrop in downtown Johannesburg, these samples are only now being cut and polished in the lab at NOVA.
My wonderfully named e-buddy Martin Bentley recently took a field trip to a quarry in South Africa (between Grahamstown and Fort Beaufort) where the Dwyka Formation is exposed: This poorly sorted sedimentary rock (a ‘diamictite’) is usually interpreted as glacial deposits (lithified till, or ’tillite’). Alfred Wegener cited these rocks and accompanying glacial striations (and … Read more
A small mountain inland of Gansbaai, South Africa (where one goes to cage-dive with great white sharks) shows some of the folding characteristic of the Cape Fold Belt. Let’s zoom in… A few bedding traces annotated, to ease your armchair fold-viewing experience. I think this is my final photo from South Africa… Wow. Only took … Read more
We wrap up our week-long odyssey along South Africa’s Hoerikwaggo Trail with a look at something we look at every Friday: folds! In this case, we’ll be examining folds in the bedding layers of the Table Mountain Sandstone.
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the ‘fynbos’ plants seen along the trail.
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the jointing, oxidizing and reducing fluid flow, and the emplacement of ore veins.
Callan continues his week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine the Table Mountain Sandstone.
Callan begins a week-long recounting of his five-day backpacking trip from the Cape of Good Hope to Cape Town, South Africa, along the Hoerikwaggo Trail. Today, we examine scenery and logistics of the trail.
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
Last winter, around 10 months ago, Lily and I were walking along the shore of Hermanus, South Africa, when I saw a little closed-drainage pool in the sandstone, harboring a briny distillation of the South Atlantic Ocean. Neat salt “rim” on the edge of the pool… Also note the ~cubic crystals at the bottom of … Read more
Another Friday, another fold. …By another Bentley!
Christie Rowe sent me these two images. They were taken by Ben Melosh and Louis Smit. The folded layers are mylonites of the Pofadder Shear Zone in South Africa. I love it when folds are expressed not only in profile, but also in three dimensions. Nothing in life could possibly be better. We’ve featured the … Read more
Grab your coffee and join Callan & Lily for a stroll along the quartzite cliffs of Hermanus, South Africa. Bedding, cross-bedding, joints, faults, veins, folded veins, and faulted veins all await you there in the morning light.
The Friday fold “guest fold” series continues with a folded ultramylonite from South Africa.
This is Dyer Island, off Gansbaai, southern South Africa, a little west of Cape Agulhas: Those are seals, a huge, crazy crowded colony of Cape fur seals. They are loud. They create a God-awful stink with all their fishy excrement. It was like being in a BBC nature program to see this firsthand. I could … 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.