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28 March 2017

P-sol in a conglomerate countertop slab

P-sol in a conglomerate countertop slab

A hardware parking lot in rural Virginia showcases an elegant slab of pressure-solution induced compaction of a conglomerate.

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9 March 2017

Lugworm casts on the beach, Islay

Lugworm casts on the beach, Islay

Who dwells beneath the sands of Islay? Lugworms do. These embedded annelids process the sediment for food, extruding the undigested sand in charismatic piles that adorn the beach of Loch Gruinart.

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1 February 2017

An oddball at Eshaness

An oddball at Eshaness

In eastern Shetland, the sea chews away at the innards of a Devonian stratovolcano. But there’s an odd visitor there too – and we’re not talking about the blogger.

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9 December 2016

Friday fold: Machir Bay I

Friday fold: Machir Bay I

It’s Friday! Today’s fold comes to you from Neoproterozoic metasediments on the west side of Islay, at Machir Bay.

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16 November 2016

Cobble diversity of Fetlar’s beaches

Now that we’ve examined the geology of the outcrops at Funzie Bay on the island of Fetlar in northeast Shetland, let’s stroll along two beaches. Here we have cobbles from Funzie Beach and a small beach eroded from serpentenite and metaharzburgite of the island’s ophiolite complex. Compare. Contrast. Rejoice. Link GigaPan by Callan Bentley Link GigaPan by Callan Bentley Both of these were handheld panoramas of ~60 photos apiece. It’s …

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7 November 2016

Coastal colluvium + coal contest in context

Coastal colluvium + coal contest in context

Here’s the answer to the contest: This is an outcrop on the beach at Funzie Bay, Fetlar, Shetland, U.K. The modern beach sediment is the lightest-colored, rounded cobbles at both the top and bottom of the photo. Poking out in between is a layer of light-gray colluvium (angular fragments) overlain by dark peat, now perhaps approaching lignite. Because peat in Shetland cloaks the hillsides but is unlikely to grow a …

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3 November 2016

A “triple tombolo” in northern Shetland

A "triple tombolo" in northern Shetland

We’ve taken a look already at an exemplary tombolo from Shetland. Today, I’m dialing up the tombolosity of the blog with a Triple Feature: Click to make much larger (8000 pixels wide) If you look closely here, you’ll see that only the rightmost bar fully connects the two islands. It’s the only true tombolo, sensu stricto, at this site. The other two perhaps deserve another name, though I’m not sure …

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19 October 2016

Oddball Icelandic rocks, part III: conglomerate

Oddball Icelandic rocks, part III: conglomerate

At the Volcano Museum in Stykkishólmur, I learned that Iceland has fossils. Specifically, they have a display of bivalve (clam) fossils there, and when I asked where to find them, I was directed to a point further east on the Snæfellsnes Peninsula. The next day, I set off to find them. Here was what I saw on a cliff high above me, at the spot nearest to where I thought …

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1 September 2016

Archean microbial mats in the news and in GigaPan

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.

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31 August 2016

Ball & pillow and other sedimentary structures in Graafwater Formation, Table Mountain

Ball & pillow and other sedimentary structures in Graafwater Formation, Table Mountain

In Cape Town for the International Geological Congress, Callan hikes up Table Mountain and finds some superb primary sedimentary structures in sands and shales of the Graafwater Formation.

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