Black Jasper Conglomerate slab B238

B238  Black Jasper Conglomerate slab, polished on one side.

From near Nullagine, Western Australia.

Dimensions at widest points approximately 130 mm x 70 mm x 11 mm thick

Weighs 196 grams.

Conglomerate is a sedimentary rock consisting of individual pebbles within a finer-grained matrix that have become cemented together. Conglomerates are a very common rock type that occur in numerous locations world wide. However this one is special due to it's extreme age as well as inclusions of pyrite scattered throughout. The location it comes from is near Nullagine in the Pilbara region of Western Australia. For the geologically minded, our "Black Jasper Conglomerate" is a polymictic* pebble and cobble conglomerate. It occurs in the Proterozoic Mount Bruce Supergroup which is part of the Fortescue Group with an age of approx. 2,765 million years.
*Polymictic : a conglomerate which contains clasts (fragments) of many different rock types.