Mapping the Carpentaria conductivity anomaly in northern Australia

A band across northern Queensland, Australia, was studied in 1995 by a magn etometer array experiment in two parts: a western part (Q1), and an eastern part (Q2). Forty-three sites were occupied in all, by Flinders University magnetometers which recorded in three components at intervals of 1 min. A m ajor purpose of the study was to further clarify the position and indeed th e existence of a major electrical conductivity anomaly, suspected to exist in the area from earlier reconnaissance observations. The arrays were succe ssful in clearly delineating the path of the conductivity anomaly, here ter med the Carpentaria conductor. It is seen to continue up the eastern side o f the Mt Isa Inlier, from where it was mapped in detail previously in south ern Queensland. The results show the anomaly to be offset from the 'Tasman Line', which is thought to indicate a major structural boundary in the Aust ralian Continent, and which possibly has a conductivity anomaly associated with it further south. Elsewhere the array results give a clear measure of the coast effect of northeast Australia, and they set the magnetic variatio ns recorded at Charters Towers Observatory in the context of the coast effe ct. (C) 1999 Elsevier Science B.V. All rights reserved.