The big picture for exploration in the Eastern Goldfields Province, Western Australia, defined by regional magnetic and gravity data

Abstract

Geological understanding of the Eastern Goldfields has been limited in the past by poor outcrop owing to regolith and surficial cover. The economic importance of the greenstone belts relative to gneiss and granitoids, has led to geological maps and models concentrating on the geology and geological evolution of the greenstone belts. The regional aeromagnetic and gravity data are used to derive models for the whole area, and therefore also to subdivide the non-greenstone rock. lnterpretation of these regional geophysical data sets indicates the presence of features which are tens to hundreds of kilometres long. They include gneiss-granite domains, gneiss-granite domes, greenstone terranes and large bodies of granite. Recent more detailed surveys acquired under the National Geoscience Mapping Accord provide better resolution of the internal structure of these domains and enhance characteristic anomaly patterns used to discriminate between domains. Greenstone-belt deformation has been influenced by the shape of adjacent gneiss-granite domains, granites and lineaments. The geophysical models developed provide a valuable framework in which to assemble a wide variety of geological, geochemical, and geophysical information. It is through the generation of comprehensive regional models of the geology that effective exploration of areas of poor outcrop will be developed.