PDF 51601.pdf | Request a copy Full text restricted Available under University of Tasmania Standard License.

Abstract

The Junee – Narromine Volcanic Belt of Ordovician volcanic, volcaniclastic and intrusive rocks in central
New South Wales is the most westerly structural belt of the now disrupted Macquarie Arc. Although
more than 200 km long (far longer than other belts of Ordovician arc volcanics), most of this belt is
concealed by younger Palaeozoic to Holocene cover. Most of our knowledge of this belt thus comes
from scattered outcrops and drillhole information, augmented by the interpretation of aeromagnetic
and gravity data and, to a lesser extent, information from deep seismic-reflection profiling. This
combined geological and geophysical approach suggests that the Junee – Narromine Volcanic Belt
consists of major separate igneous complexes, each consisting of lavas and volcaniclastic sediments
intruded by various mafic to felsic intrusive porphyries. Variations in age and geochemical affinities are
used to suggest that the Junee – Narromine Volcanic Belt approximates most closely the magmatic
core of the Macquarie Arc. The present geometry of the Junee – Narromine Volcanic Belt reflects the
interplay of two major ductile – brittle fault systems: the north-northwest-trending Gilmore Fault System
mainly in the south and the north-trending Tullamore Fault System, mainly in the north and centre,
together with local west-northwest cross faults. These systems were generated during deformation in the Early Silurian, Early Devonian and Carboniferous.

Item Type:	Article
Authors/Creators:	Glen, RA and Spencer, J and Willmore, A and David, V and Scott, RJ
Keywords:	geology, geophysics, igneous complexes, Junee – Narromine Volcanic Belt, Lachlan Orogen, Macquarie Arc, Ordovician, structure.
Journal or Publication Title:	Australian Journal of Earth Sciences
ISSN:	0812-0099
DOI / ID Number:	https://doi.org/10.1080/08120090601146805
Additional Information:	The definitive version is available online at http://www.informaworld.com/smpp/content?
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page