Canbelego Explanatory Notes (1981)

Abstract

The Canbelego 1:100 000 map sheet area is part of the Cobar 1:250 000 map sheet area. This publication includes the 1:100 000 geological map sheet. An appendix contains a fossil listing and there are Photographs, etc. to complement the text. The area described by the Canbelego 1:100 000 map sheet area and notes is important insofar as it includes geological units which are hosts to several important mineral occurrences. The area lies in the northwestern part of the Lachlan Fold Belt, including the Cobar Synclinorial Zone, Girilambone-Wagga Anticlinorial Zone and the Mineral Hill Synclinorial Zone. Outcrop is moderately good. The main Palaeozoic rocks are the Girilambone Group [termed Girilambone beds in this publication], Nymagee Igneous Complex and the Cobar Supergroup. Of these the Girilambone Group forms the basement and is a metamorphosed turbiditic sequence of lower to upper greenschist grade - although localised areas are up to amphibolite grade adjacent to the intrusive Nymagee Igneous Complex. The Girilambone Group is extensively folded, with slaty and crenulation cleavage, the latter becoming more prominent and more complex and pervasive from west to east as grade increases. The Nymagee Igneous Complex includes massive and foliated granitoids - of probable middle Silurian age. Deep and shallow water sedimentation made up the Early Devonian Cobar Supergroup, made up of the Nurri, Kenmure and Kopyje Groups. Some, in places predominant, igneous influences are present. Metamorphism of the Cobar Supergroup is generally no more intense than lower greenschist grade. Minor intrusive activity (quartz diorite) may be of Middle Devonian age. Extensive Cainozoic deposits include gravel and silcrete, and alluvium. Known mineral deposits in the Canbelego 1:100 000 map sheet area are smaller than those to the north, and include gold in quartz and/or sulphide-quartz veins and with sulphide disseminations in the Girilambone Group, and copper and copper-gold mineralis

Reference

Felton E.A., 1981. Geology of the Canbelego 1:100000 Sheets 8134. New South Wales Geological Survey, Sydney.