You are browsing the archive for stromatolites Archives - AGU Blogosphere.

9 August 2017

A suite of new 3D models

A showcase of five new 3D digital models of awesome rock samples and outcrops, produced using Agisoft Photoscan.


21 December 2016

Stromatolites of Bunnahabhain

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, too – it’s called the Bonahaven Dolomite. Unlike what you might expect for a cap …


1 September 2016

Archean microbial mats in the news and in GigaPan

The news yesterday of 3.7 Ga stromatolites in Greenland prompts a closer look at 3.22 Ga microbially-induced sedimentary structures in the Barberton Greenstone Belt’s Moodies group sandstones.


2 August 2016

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

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 “Split rock” — Go figure. The Split Rock is an easy landmark to steer toward …


28 June 2016

“Dunbar marble” at Barns Ness, Scotland

Thanks to the website, 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 is the most extensive limestone outcrop in central Scotland. I set my field assistant loose …


10 June 2016

Green River Formation stromatolite – a virtual sample

Today concludes a weeklong run of┬ávirtual 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 Wilkins Creek member of the Eocene-aged Green River Formation of southwestern Wyoming: [gigapan id=”187031″] Link …


29 March 2016

Four new GIGAmacro images

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: [gigapan id=”185543″] 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.) Banded iron formation from Minnesota with ooids and stromatolites: [gigapan id=”185076″] Link Intrusion …


9 December 2015

Thrombolites of the Great Salt Lake, Utah

I saw mention of thrombolites exposed along the shore of Antelope Island in the Great Salt Lake the other day in my Facebook feed; because the description cited a professor at Westminster College in Salt Lake City, I prompted my friend and colleague Tiffany Rivera, also a geology professor at Westminster, to go check it out and get me some bloggable photos. As it turned out, she already had – …


25 December 2014

The stromatolites of Helen Lake 2: GigaPans

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. [gigapan id=”159358″] link [gigapan id=”159462″] link [gigapan id=”159461″] link [gigapan id=”159459″] link [gigapan id=”159458″] link [gigapan id=”159355″] link [gigapan id=”159359″] link Finally, three other non-stromatolitic GigaPans from the site: One of Artomys Formation siltstone / shale interbeds… [gigapan id=”159354″] link …and two …


22 December 2014

Digitate stromatolites

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: [gigapan id=”159489″] link


25 December 2012

Stromatolites of the Green River Formation

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 side of the White Mountain escarpment in the Green River Basin. Here’s the view to …