General view looking east from the base of the steps at Moulin Huet Bay in Guernsey

Moulin Huet Bay lies on the edge of a plateau in southern Guernsey that is largely composed of Icart Gneiss. It forms part of the Southern Metamorphic Region in this Channel Island. Icart Gneiss is a pale grey, coarse-grained metamorphic rock containing large pinkish feldspar crystals in the midst of deformed masses of quartz, mica, and hornblende (de Pomerai and Robinson 1994) giving the rock a rather “squashed” appearance. It was originally an intrusion of granite, dating from around 2000 and 2500 million years ago, into even older rocks.

The colours and textures are extremely varied, depending sometimes on the angle and section viewed, the freshness of the exposure, degree of weathering, and number of encrusting organisms like lichens and algae. Some of these rock texture photographs are taken really close up so that you can see the individual crystals, especially the pinkish-orange feldspar. Others were taken at a greater distance showing the patterns of all the crystals within the matrix. The base of the cliffs was composed of this gneiss and so were the jagged outcrops on the beach (up to 5m in height) and the scattered boulders.


De Pomerai, M. and Robinson A. 1994 The Rocks and Scenery of Guernsey, illustrated by Nicola Tomlins, Guernsey: La Société Guernsaise, ISBN 0 9518075 2 8.

8 Replies to “Rocks at Moulin Huet – Part 1”

  1. Thank you, Aidy. I am sure you are right. I wonder if there are any locations in Ireland with rocks of the same antiquity as Guernsey, where some of the rocks date from 2600 million years ago or earlier?


  2. This looks a pretty and interesting bay, thanks. Your photos made me ponder timescales and sizes. Then I googled the bay and found out that Renoir painted it too. Different focus of view of course, but still beautiful.


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