Australia: The Land Where Time Began

A biography of the Australian continent 

Newmarracarra Limestone

According to the authors¹ the Newmarracarra Limestone is probably the best known of the marine rock deposits from the Middle Jurassic. This is a sequence that is highly fossiliferous and formed under shallow near-shore marine conditions and now outcrops near Geraldton, the Perth Basin, on the southwest coast of Western Australia. Isolated remains of marine reptiles and dinosaurs have been found in the Colalura Sandstone, one of a number of  marine units that are overlain by the Newmarracarra Limestone, containing a fossil assemblage dominated by bivalves and cephalopods, that is slightly younger than the underlying units. These fossils are in a greyish-yellow limestone that was formed mainly by a hash of bivalve shells. A middle Bajocian age has been determined for the unit by the mollusc fauna, especially ammonites, of the Newmarracarra Limestone.

Sources & Further reading

1. Kear, B.P. & Hamilton-Bruce, R.J., 2011, Dinosaurs in Australia, Mesozoic life from the southern continent, CSIRO Publishing.