Genesis of Felsic Plutonic Magmas and Their Igneous Enclaves: The Cobaw Batholith of Southeastern Australia
John D Clemens, Roland Maas, Tod E Waight, Luke K Kunneke
JOURNAL OF GEOLOGY | UNIV CHICAGO PRESS | Published : 2016
The Late Devonian postorogenic Cobaw batholith, in southeastern Australia, is an oval, east-west-orientated, terranestitching lopolith that intruded low-grade metaturbidites. The initial intrusion (at 370 Ma) was the small, hypabyssal, S-type Rainy Creek Rhyolite (RCR). At 369 Ma, the foliated S-type Pyalong pluton was emplaced, apparently along an east-west-orientated fracture zone. Around 367 Ma, the main I-type Baynton pluton intruded as numerous shallowdipping sheets. The last plutonic event was the intrusion of the broad, thin, flat-lying, and crosscutting sheet of the Itype Beauvallet pluton. The Cobaw plutons had independent origins, with magmas derived from contrasting, internally he..View full abstract
Some of the work presented here is derived from the BSc (Hons) thesis of L. K. Kunneke. The South African National Research Foundation is acknowledged for financial support in the form of its Funding for Rated Researchers scheme; this allowed J. D. Clemens to undertake fieldwork and sample collection and to obtain elemental and isotope analyses. We thank A. Rossiter for the provision of numerous chemical analyses from his PhD thesis. The incisive and constructive comments by the editor and R. Vernon are also gratefully acknowledged.