K-AR DATING OF THE ANAKIE METAMORPHIC GROUP - EVIDENCE FOR AN EXTENSION OF THE DELAMERIAN OROGENY INTO CENTRAL QUEENSLAND

The Anakie Metamorphic Group of central Queensland is a multiply defor med sequence of psammitic to pelitic metasedimentary and mafic igneous rocks. Although the depositional age is still uncertain, this paper p resents K-Ar dates from four samples which indicate that the sequence was deformed at about 500 Ma in the Middle Cambrian, and thus forms pa rt of the Delamerian-Ross Orogen of southern Australia and eastern Ant arctica. Lithologically and structurally similar rocks in the Lolworth -Ravenswood Province, farther north in Queensland, may also be part of this belt. The significance of an older age of about 540 Ma from a fi fth sample is uncertain. A sixth sample gave a younger age of about 47 0 Ma and may be partly reset.