A cordierite-bearing granite suite from the New England Batholith,N.S.W., Australia

A suite of cordierite-bearing biotite-muscovite intrusive granites in the New England Batholith, New South Wales, outcrops over 3400 sq km and is the largest reported occurrence of granites of this type. Compositionally the granites are close to the low temperature minimum and display only limited chemical variation. The corundum-normative nature of the granites suggests a pelitic sedimentary parentage. Cordierite with an average 100 Mg/ Mg + Fe of 55 occurs as large tabular crystals and is considered to be a refractory phase brought up from the zone of partial melting. The presence of cordierite and the absence of garnet in these granites suggests a partial melting at a pressure maximum of 6 kb, equivalent to 22 km depth.