#DogWalkingGeology Another loose rock from Ardalanish beach in SW Mull from this morning. This is a really distinctive rock, from the andesitic sills forming the lower part of the Glencoe volcanic sequence, 85km to the NE. Transported by glaciers. The purple alteration is partly hematite, but also distinctive pink manganese-rich epidote , which you can see in the core of the pale patch on the left of the cobble. #Geology#Mull#Glencoe
🤓 Fun Fact: these purplish altered Glencoe andesites are similar in colour, , chemistry and mineralogy to the famous Imperial Porphyry quarried by the Romans at Jabal Dokhan, in Egypt. I wonder if any of the Glencoe rocks might be carvable? https://www.dailyartmagazine.com/red-porphyry-symbol-of-imperial-power/
Add comment