stromatolites

Stromatolites of Bunnahabhain

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Remember the diamictite I featured here a few weeks ago, from Islay? It was the one that might be a Snowball Earth diamictite. Well, if you follow Snowball Earth science at all, you’ll doubtless be aware that the glaciogenic sediments are characteristically overlain by “cap” carbonates. There’s a stratigraphic successor to the Port Askaig Tillite, … Read more

Oldest fossils in the UK: M.I.S.S. in Stoer Group, Scotland

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This is the Split Rock at Clachtoll, on the shore of the North-West Highlands of Scotland. You’re looking out to sea, over the Minch. It’s the site that graces the cover of the excellent book A Geological Excursion Guide to the North-West Highlands of Scotland, by Kathryn Goodenough and Marten Krabbendam. “Clach toll” apparently means … Read more

“Dunbar marble” at Barns Ness, Scotland

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Thanks to the website ScottishGeology.com, run by Angus Miller, I learned of Barns Ness, a Mississippian-aged limestone fossil site on the shore not far from where we are staying at Dunbar. We ventured out there on Saturday afternoon, in search of fossils. The presence of the Dunbar Cemenet Works nearby is an indication that this … Read more

Green River Formation stromatolite – a virtual sample

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Today concludes a weeklong run of virtual samples. For the past five days, I’ve been presenting examples of a visualization combination that leverages the advantages of the GIGAmacro system with the 3D ‘virtual sample’ perspective of the Sketchfab-hosted model: the same sample presented in both formats. Today, we finish up with a stromatolite from the hypersaline … Read more

Four new GIGAmacro images

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Here are a few new images I’ve been working on with my home-based Magnify2 imaging system from GIGAmacro. Archean basement complex gneiss from the Gallatin Range of Montana: Link (If this looks familiar, that’s because one of the samples I imaged with the Photoscan 3D modeling technique and published on Sketchfab the week before last.) … Read more

Stromatolites of the Helena Formation, Grinnell Glacier Cirque, Montana

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My favorite place to have lunch in Montana is at the Grinnell Glacier cirque in Glacier National Park. This is the dining room table: You’re looking at a bedding-plane-parallel exposure of Mesoproterozoic stromatolites here. Every few years, I’m lucky enough to hike up there with motivated students and share food atop this unparalleled view into … Read more

The stromatolites of Helen Lake 2: GigaPans

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Posted this morning as my “Christmas gift” to blog readers in both photo and GigaPan form, here are the exquisite stromatolites of Helen Lake, Banff National Park, Alberta. link link link link link link link Finally, three other non-stromatolitic GigaPans from the site: One of Artomys Formation siltstone / shale interbeds… link …and two of … Read more

Digitate stromatolites

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Want to see something cool? Itty bitty stromatolites… like baby’s fingers! There’s a big weathered-out stylolite at the base of this stromatolite-bearing layer, too.   These elfin stromatolites are part of the boulder in the lower left (foreground) of this GigaPan, taken at the Icefields Center parking area in Jasper National Park, Alberta: link

Stromatolites along the trail to Crypt Lake

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On the trail up to Crypt Lake in Waterton Lakes National Park (southernmost Alberta, Canada), there’s a ‘traditional’ hiking trail, and then an intense ledge on a glacial headwall that you must teeter along, including scaling your body up into and through a person-sized tunnel! Right at the transition between the two “phases” of the … Read more

Stromatolites of the Green River Formation

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The summer before last (2011), I spent some time in Wyoming on an energy resources field trip run by Sheridan College, and one stop we made was to look at “oil shale” (really kerogen-rich marlstone) of the Green River Formation, an Eocene lake deposit in southwestern Wyoming. The oil shale is exposed on the east … Read more

Geology and wine in northern Virginia, part II: the Valley & Ridge

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Callan attends the Geological Society of Washington’s fall field trip, examining the relationship between grape-growing and the underlying geology of two provinces in northern Virginia: the Blue Ridge and the Valley & Ridge. With GSW compatriots, Callan visited Hume Vineyards in the central Blue Ridge province and North Mountain Vineyard and Winery in the Shenandoah Valley. This is part II of the field trip report.

Friday fold: scenes from the trail to Bertha Lake

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Given that I’m leaving tomorrow for the Canadian Rockies, I’ve been inspired to look through some of my photos from last summer, and to realize how few of them I’ve blogged so far. So let me show you some folded things today that Lily and I saw the afternoon we arrived at Waterton Lakes National … Read more

Snowball students visit the University of Maryland

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The final meeting of my spring semester Snowball Earth class was a field trip to the University of Maryland, hosted by Snowball guru Jay Kaufman, a specialist in chemostratigraphy using stable isotopes. Here, Jay welcomes the class to his wet lab: Doing chemostratigraphy takes lots of samples. Here’s a drawer full of samples from one … Read more

Paleoproterozoic stromatolites from the Malmani Dolomite (Transvaal Supergroup)

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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