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 … Read more

Friday fold: orogeny in a cobble

Happy Friday. Thank goodness it’s the last one before this horrible election season finally concludes. Let’s celebrate with two cobbles from the beach at Papil Water, Fetlar, Shetland. They show small-scale folds in metasedimentary and metavolcanic rocks of Ordovician or Silurian age, part of the ophiolite complex that makes up most of Fetlar. Each is … Read more

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 … Read more

Friday folds: Dalradian schists at St. Ninian’s Isle

Remember St. Ninian’s Isle? It is connected to Mainland Shetland by a tombolo. But it has rocks there, too. Here are some outcrops on the beach: If you visit these schisty fins, you’ll find they are populated by a cavalcade of small folds. Some of the folds are crisp things known as kink bands: Annotated … Read more

Northwest Highlands unconformities (3 of 3): Sub-Ardvreck

It’s time to cover the third and final unconformity I observed this summer in the North-West Highlands of Scotland: the unconformity between the Neoproterozoic Torridonian Group below and the Cambrian Ardvreck Group above. Where I saw it, south of Loch Assynt on the mountain called Beinn Garbh (north of Canisp), it actually is displayed alongside … Read more