DEPTH TO BASEMENT CHARACTERISATION IN THE EASTERN PART OF THE MOUNT ISA PROVINCE

URL: https://geoscience.data.qld.gov.au/dataset/cr135660

This report, by CSIRO Minerals and Geological Survey of Queensland authors, derives a probabilistic depth to basement map in the Cloncurry area, in the Mount Isa province, Queensland. A magnetotelluric (MT) survey consisting of 978 soundings acquired over 2 campaigns in 2016 and 2020 by the Geological Survey of Queensland was modelled using a probabilistic workflow consisting of 2 successive steps: 1) the MT data is inverted using a 1D trans-dimensional Bayesian algorithm, and the results are used to extract depth to basement probability distributions for each MT site independently. Then, 2) these were laterally combined, along with drill hole data constrained by surface geological data and the location of structural faults using a Bayesian Estimate Fusion algorithm. The results consist in depth to basement probabilistic maps in the 3D space. We observed a thickening of the cover toward the north and the east, which is supported by the drill holes and the magnetic data. The Mount Margaret and Quamby faults appear to control the basin thickening to the east and west of the survey.

Reference: Seillé Hoël, Visser Gerhard, Janelle Simpson, Dominic Brown and Matthew Greenwood 2022 Depth to basement characterisation in the eastern part of the Mount Isa Province. CSIRO Report EP2022-5168.