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Day 172 : This is a crystal-lithic-vitric lapilli tuff from a welded pyroclastic ash flow unit. From Nant Ffrancon, Snowdonia, Wales. Keele Collection. 

Day 171 : A blastomylonitic psammitic gneiss from Seljestad, Norway. Keele Collection.

Day 170 : A biotite-rich blastomylonite schist from Akland, Norway. 

Day 169 : Returning to the fault rocks theme, and the Scotchport Harbour Slide on the Mullet Peninsula in C. Mayo, Ireland, this is an acid (phlogopite-muscovite-quartz) blastomylonite schist.

Day 168 : In the field today looking at a couple of RIGS sites.  This is the Star Wood Dolomite, an ankeritic limestone from near Cotton, Staffordshire.  It preserves goniatites in 3D that elsewhere in the shales are flattened.  It forms the lower leaf of the Bilinguites gracilis (formerly Reticuloceras …

Day 167 : A mylonite gneiss formed by ductile shearing of a granite from Andorra la Vella, Andorra.

Day 166 : Another folded mylonite, this time a calcareous one from the Val d’ Hérens, Switzerland. Keele Collection.

Day 165 : Continuing the fault rocks theme, this is a basic blastomylonite schist containing hornblende and phlogopite.  From the Scotchport Harbour Slide, Mullet Peninsula, Co. Mayo, Ireland

Day 164 : A megacrystic mylonitised feldspar augen gneiss from a Hercynian granite protolith in the South Brittany Shear Zone. From Marzan, near La Roche-Bernard, Southern Brittany, France. Keele Collection.

Day 163 : Mylonitised St Peter Port Gabbro, Hougue a la Pere, St Peter Port Guernsey, Channel Islands.  Keele collection.