Syn‐deformational remanent magnetization of the Mount Eclipse Sandstone, central Australia

• Published in: Geophysical Journal International
• Main Authors: Li, Z. X., Powell, C. McA, Schmidt, P. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1989
• Subjects: Carboniferous; Gondwanaland; overprint; palaeomagnetism; Pangaea; syndeformational; South pole
• Online Access: https://researchers.mq.edu.au/en/publications/99408d6a-9933-4b52-b2e3-735ead5a763f; https://doi.org/10.1111/j.1365-246X.1989.tb02025.x; http://www.scopus.com/inward/record.url?scp=0024874608&partnerID=8YFLogxK

The palaeomagnetism of the latest Devonian‐Early Carboniferous Mount Eclipse Sandstone in central Australia reveals samples from 16 out of 31 sites having a consistent hightemperature component of natural remanent magnetization. Site‐mean directions from the two limbs of the most detailed studied syncline attain their best grouping after 75 per cent of ‘unfolding’, and further ‘unfolding’ causes a ‘cross‐over’ feature. Mineralogical studies using microscope and electron microprobe show that this remanance is most likely to be carried by secondary haematite formed by alteration of Fe‐rich minerals during the midCarboniferous deformation. Four different models are examined to reconstruct the palaeohorizontal for the syn‐deformational remanence. The best estimate of the palaeomagnetic South Pole position is lat. = 33.8°S, and long. = 121.2°E (dp = 19.2°, dm = 19.7°), close to Australia. This result indicates a rapid polarward movement of eastern Gondwanaland during the first half of the Carboniferous. We also suggest that the widespread Alice Springs Orogeny‐related overprints in central Australia were acquired during the beginning of the main phase of deformation in the mid‐Carboniferous.