Resolving the Paleogeographic Puzzle of the Lhasa Terrane in Southern Tibet

Abstract

Microcontinental fragments are important components of ancient orogenic belts, and understanding their paleogeography is fundamental for reconstructing their evolution. It is however, often problematic to establish precise paleogeographies for such fragments due to the difficulty in defining features that uniquely link them to specific regions of broader continental reconstructions. This problem is exemplified by the Lhasa Terrane in southern Tibet, now a part of the Eurasian Tethyan Orogenic Belt. This terrane has been variously positioned adjacent to northern India (

Low‐Angle Normal Faults on the NW Shelf of Australia: Implications for Late Paleozoic Rifting

“…A similar extensional setting in the Early-Middle Permian has also been suggested for the Lhasa microcontinent in eastern Gondwana, which was positioned adjacent to the NW Shelf during this time (Wang et al, 2021). In addition, the Late Paleozoic extension swas accompanied with widespread arc magmatism (Wang et al, 2021;Zhu et al, 2010Zhu et al, , 2011.…”

“…The timing of large-magnitude extension in the proximal margin of the Northern Carnarvon basin is consistent with regional tectonic development of the Perth basin (Rollet et al, 2013) and the Canning Basin (Müller et al, 2005;Reeckmann & Mebberson, 1984), where growth strata associated with low-angle normal faults development are observed. A similar extensional setting in the Early-Middle Permian has also been suggested for the Lhasa microcontinent in eastern Gondwana, which was positioned adjacent to the NW Shelf during this time (Wang et al, 2021). In addition, the Late Paleozoic extension swas accompanied with widespread arc magmatism (Wang et al, 2021;Zhu et al, 2010Zhu et al, , 2011.…”

“…The first phase of rifting, which began in the Late Carboniferous and continued throughout the Permian (Deng & McClay, 2019b), separated a sliver of continental fragments including the Sibumasu, Qiangtang, and Lhasa blocks (collectively named as the Cimmerian continent) from the northern margin of Gondwana (Harrowfield et al., 2005; Metcalfe, 2006, 2013; Paschke et al., 2018). Recent studies indicate that rifting along the northern margin of eastern Gondwanaland was most likely associated with subduction‐induced back‐arc extension (Morón et al., 2019; Wang et al., 2021; Zhu et al., 2010, 2011) that formed a wide (∼600 km) intracontinental rift along the NW Shelf of Australia (Harrowfield et al., 2005). In the proximal part of the NW Shelf, this phase of extension generated a series of NE‐trending half‐grabens on the Mermaid Nose in the eastern Dampier Sub‐basin (Figure 2) (Langhi & Borel, 2005) and on other parts of the NW Shelf (Deng & McClay, 2021; I’Anson et al., 2019; Southby et al., 2018).…”

“…The first phase of rifting, which began in the Late Carboniferous and continued throughout the Permian (Deng & McClay, 2019b), separated a sliver of continental fragments including the Sibumasu, Qiangtang, and Lhasa blocks (collectively named as the Cimmerian continent) from the northern margin of Gondwana (Harrowfield et al, 2005;Metcalfe, 2006Metcalfe, , 2013Paschke et al, 2018). Recent studies indicate that rifting along the northern margin of eastern Gondwanaland was most likely associated with subduction-induced back-arc extension (Morón et al, 2019;Wang et al, 2021; Hill (1994). The continental crust of the inboard Northern Carnarvon Basin can be divided into proximal, necking, and highly-extended domains based on crustal thicknesses.…”

Leucogranite Records Multiple Collisional Orogenies

“…Kernel density estimation (with bandwidth of 12) of (a) inherited cores (>50 Ma) in leucogranites of this study; (b), Tethyan Himalayan sequence (THS); (c), Higher Himalayan sequence (HHS); (d), Vindhyan Basin in the India craton.See text for the interpretation of age groups. Data source: THS(Cai et al, 2016;Clift et al, 2014;Liu, Dai et al, 2020;McQuarrie et al, 2008;Myrow et al, 2009Myrow et al, , 2010Najman et al, 2017;Shen et al, 2016;Wang et al, 2021;Zhu et al, 2011), HHS(Gehrels et al, 2006a;Gehrels et al, 2006b;Martin et al, 2005), and Vindhyan Basin(Turner et al, 2014).…”