To the north of the city of Adelaide, this site is one of only a handful around the world where fossiliferous rocks dating from the Pre-Cambrian period (680-600 million years ago) are exposed. Fossils found here include the impressions of many soft-bodied animals. With no hard (calcareous) body parts it is extremely rare for soft-bodied animals to be preserved as fossils. The Pound Quartzite rocks of this region have produced specimens of the annelid worms Spriggina and Dickinsonia and the jellyfish Medusina, Rugoconites and Cyclomedusa and the colonial feather-like "seapen" Charnodiscus.