A dyke of teschenite occurs in the Red Rocks Gorge near Allens Creek. It is oriented northwest–southeast and heads towards Kambah Pool Area. A similar dyke also outcrops on the west side of the Murrumbidgee River near Pine Island. The dyke is less than 0.5 metres thick. The rock is black, showing up well against the reds and browns of the Laidlaw Volcanics.
