Fossiliferous graphite from Undercliff, New South Wales

Abstract

Graphite in a contact metamorphic aureole around adamellite at Undercliff, northern New South Wales, contains fossil leaves of the Glossopteris flora. Investigations by differential thermal analysis, X‐ray diffraction, chemical analysis, and electron microscopy confirmed the graphitic nature of the material but showed it to be less well‐crystallised than the well‐known commercial graphites of Passau (Germany) and Ceylon. It is inferred that such differences in crystallinity are due to the different metamorphic environments in which the three graphites formed. The presence of fossil leaves in the Undercliff material indicates an organic origin for this graphite. Probably the sediment from which it was derived was a carbonaceous shale or coal of Permian age.