19 October 2016

Oddball Icelandic rocks, part III: conglomerate

Posted by Callan Bentley

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 I was supposed to be looking:



There were some suspicious looking outcrops there…


I climbed up. Here’s the view from on high…


Rotating, I faced the cliff.

In detail, the outcrop object of my quest showed inclined packages of conglomerate:

iceland-seds-foresetssmClick to make much, much larger

A few adjacent details:



This was the only outcrop of sedimentary rock I saw anywhere in Iceland. It was too coarse for delicate external molds of clams, but it was cool in its own right on account of its unique status in my experience.

There were also a few boulders showing rotated blocks of the stuff:





And here’s a cobble hosting a decent graded bed:


And there you have it. With the green ignimbrite and the granite intrusion, those are the only three rocks I saw in a week in Iceland that weren’t mafic volcanics.