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22 April 2022
His 48th summer on top of the world
This June, George Divoky will refurbish a cabin that sits on a lonely gravel island north of Alaska. He was not planning a remodel this year. Sometime during the winter, a polar bear tore through a plywood wall of the cabin Divoky moved 20 years ago to Cooper Island.
8 March 2019
Friday fold: Dent de Morcles
The Friday fold is a recumbent anticline/syncline pair, deforming the K/Pg boundary in the Swiss Alps, as photographed from the air by Bernhard Edmaier.
14 September 2018
Friday fold: Ferruginous sediments in Barberton Mountain Land
A trip back to Archean sedimentary rocks in Barberton, South Africa, reveals a few folds on the roadside…
5 September 2018
The Intersection of Climate Science and Hope: A Personal Story
As a native of the Timbuktu region in Mali, West Africa, one of the most unstable areas of the country, I have been an eyewitness to the devastating effects of climate variability and change on people’s lives.
5 June 2018
Cross-bedding in Archean komatiitic ash deposits
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.
20 April 2018
Friday fold: Isoclinal in Damaraland
A guest Friday fold from Graham Andrews of West Virginia University: Graham describes this as an almost along axis view of a huge isocline in the Damaraland belt, Namibia Thanks for sharing! And a happy Friday to all.
23 February 2018
Friday fold: some Google Earth views of Namibia
We return today to the scene of last week’s Friday fold, for it turns out that you can see some additional awesome folds from outer space (via Google Earth). Do not adjust your monitor: these patterns mean show up a stark and wavy reality!
21 February 2018
Born a Crime, by Trevor Noah
Trevor Noah is a South African stand-up comedian who rocketed into American awareness when he was selected as the successor to Jon Stewart as the host of Comedy Central’s news program The Daily Show. This book is Noah’s autobiography of growing up in South Africa, at first under apartheid, and then in the new post-apartheid era. It is the best account I’ve read of the institutional and cultural structure of …
16 February 2018
Friday fold: Zerrissene turbidite system, Namibia
The University of Maryland’s Jay Kaufman makes our Friday fold happen by sharing some images of folds from the Zerrissene turbidite system of northwestern Namibia.
12 January 2018
Water and sediment: news from the Mara Wetland, Tanzania
I realised that even in remote areas you are never alone. Thanks to the support of BirdLife International I had the chance to talk with people of the local communities.
2 November 2017
Weathering in komatiite
This morning on Twitter I was reminded of komatiites, those “extinct” ultramafic lavas that were relatively common eruptions during the Archean. I’ve actually got a good number of komatiite photos to share from my time last year in South Africa’s Barberton Greenstone Belt. But since time is short this morning, I’ll start with a short photo set of three images, all showing different aspects of how these ultramafic rocks weather …
25 May 2017
Chert-slab conglomerate from the Fig Tree Group, Barberton
Deep in the Archean, things suddenly got violent in the deep water of the Mapepe Formation’s oceanic setting. What was a quiet precipitation of chert suddenly was torn apart and tumbled downslope. Was an earthquake to blame? A bolide impact? This is the result.
1 May 2017
Accretionary lapilli from Archean volcanic eruptions
Volcanic “hailstones” called accretionary lapilli rained down on South Africa 3 billion years ago, and have survived to be seen in the present day, along the R40 road through Barberton Mountain Land, near the Bulembu border crossing into Swaziland.
10 March 2017
Friday fold: Sheba Mine sample
When touring the geology of the Barberton Greenstone Belt last August, our group visited the Sheba Mine, a gold mine high in the hills. Their geologist kindly showed us around and allowed us to visit his history-laden office. I have no idea where this sample originated, but it was the only fold I saw in the place, nestled between sepia-toned photographs and old lanterns and rusty picks. I wonder what …
2 February 2017
Banded iron formation in Barberton Mountain Land
Banded iron formation is an “extinct rock” that can be found in ancient marine strata such as those found in the Barberton Greenstone Belt. Visit an outcrop on the Barberton GeoTrail and contemplate the bizarre anoxic world that Earth used to be.
25 January 2017
Y-shaped joints on a basalt flow, Lake Mývatn, Iceland
A basalt flow in Iceland shows both enticing pahoehoe and fractures with a Y-shaped intersection pattern. Comparisons to bread loaves and east Africa suggest a reason why.
11 January 2017
More Messengers from the Mantle
Since I showed off the 3D kimberlite intrusion breccias yesterday, I feel as if I owe you some other photos from that lovely exhibit at the IGC. I apologize for the poor quality of these photos – the gorgeous samples were behind glass and brightly lit, which made photography difficult. But the rocks are sooooooooo pretty, I think you’ll enjoy viewing them just the same. Let’s start with a gargantuan …
10 January 2017
Two kimberlite intrusion samples presented in 3D model format
While in Cape Town for the 35th meeting of the International Geological Congress in August/September, I was delighted at the “Messengers from the Mantle: Craton Roots and Diamonds” exhibit on kimberlites. It was a world-class collection of excellent specimens that traveled to the Congress from across the city at the University of Cape Town. I took some photos of two specimens to make 3D models from, and my student Marissa …
28 October 2016
Friday fold: “the eye of Sauron” at Sibubule
Have a look at this week’s Friday fold – but be aware that it will be looking back!
26 October 2016
Archean meteorite impact evidence from the Fig Tree Group in Barite Valley, Barberton Greenstone Belt, South Africa
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.
