Magnetic and chemical stratigraphy for the Werribee Plains basaltic lava flow-field, Newer Volcanics Province, southeast Australia: implications for eruption frequency

Abstract

Data from diamond drillholes and geophysically-logged wells have been combined with surface data to produce a stratigraphy for the Werribee Plains lava field, in the easternmost part of the Cenozoic Newer Volcanics Province, southeastern Australia. Outcrop is scarce in the Newer Volcanics Province, hence nine diamond drillholes (up to 110 m deep) and 40 wells have provided a fresh perspective of the geology of this intraplate basaltic lava flow-field. Two to three samples from every flow unit identified in drillcore were demagnetised (175 samples). The primary remanent magnetisation was identified in the majority of the samples and the results were used to establish a magnetostratigraphy. Sa..