Rock 365 : Day 67 : Mantle Xenoliths #365photos

Day 67 : These are olivine-rich mantle xenoliths in a basalt. The sample was one of the first I collected as an A-level geology student many years ago from the Carboniferous volcanic vent at Calton Hill, near Buxton on the edge of the Peak District.  Since I collected this sample much of the quarry has been in-filled with domestic refuse and what exposure remains is heavily weathered.  Fresh samples like this are hard to obtain now.