Heinson Graham, Kay Ben, Baker David, Margiono Relly
Department of Earth Sciences, University of Adelaide, Adelaide, Australia.
State College of Meteorology, Climatology, and Geophysics, Tangerang, Indonesia.
Sci Rep. 2025 Jul 1;15(1):22008. doi: 10.1038/s41598-025-02830-1.
Central Australia preserves a record of micro-continent and craton accretion during assembly of the Paleoproterozoic Nuna supercontinent 2500 - 1600 Ma, followed by Mesoproterozoic magmatic and orogenic events that formed the Musgrave Province. The Petermann Orogeny (630 - 520 Ma) and Alice Springs Orogeny (450 - 300 Ma) resulted in north-south crustal shortening and Moho offsets up to 20 km that yield gravity variations of ~ 160 mGals. Three-dimensional inversion of 614 long-period (10-10000 s) AusLAMP MT and 36 geomagnetic depth sounding (GDS) sites spaced ~ 55 km produced resistivity estimates to 250 km depth, covering 1500 km west-east, 1300 km north-south. From 0 to 5 km, resistivity maps the extent and thickness of Neoproterozoic Officer, Amadeus, Ngalia and Georgina Basins, and Mesozoic Eromanga basin. At all crustal depths the Arunta Province and northern Musgrave Province are resistive (> 10000 Ω.m), bounded by lower crustal conductive zones (< 10 Ω.m) to the north, east and south that align with suture zones associated with Paleoproterozoic accretion of ribbon continents. Lithospheric scale faults active in the Petermann Orogen (Woodroffe Thrust) and Alice Springs Orogen (Redbank Shear Zone) align with these low-resistivity zones, and we argue that graphite from carbon burial in Paleoproterozoic sediments reduces frictional strength and enable compressive deformation to localise strain.
澳大利亚中部保存了古元古代努纳超大陆在2500 - 1600百万年前聚合期间微大陆和克拉通增生的记录，随后是形成马斯格雷夫省的中元古代岩浆作用和造山事件。彼得曼造山运动（630 - 520百万年前）和爱丽斯泉造山运动（450 - 300百万年前）导致地壳南北向缩短，莫霍面错断达20千米，产生了约160毫伽的重力变化。对614个长周期（10 - 10000秒）的澳大利亚大地电磁阵列（AusLAMP）大地电磁测深点和36个地磁测深（GDS）点（间距约55千米）进行三维反演，得出了至250千米深度的电阻率估计值，覆盖东西1500千米、南北1300千米的范围。在0至5千米深度，电阻率描绘了新元古代奥菲瑟、阿马迪厄斯、恩加利亚和乔治娜盆地以及中生代伊罗曼加盆地的范围和厚度。在所有地壳深度，阿伦塔省和马斯格雷夫省北部均具有高电阻（>10000Ω·m），其北部、东部和南部由与条带状大陆古元古代增生相关的缝合带处的下地壳低导电带（<10Ω·m）所界定。彼得曼造山带（伍德罗夫逆冲断层）和爱丽斯泉造山带（红岸剪切带）中活动的岩石圈尺度断层与这些低电阻率带一致，我们认为古元古代沉积物中碳埋藏形成的石墨降低了摩擦强度，使压缩变形能够局部化应变。
