Research Article| February 26, 2019 No collision between Eastern and Western Gondwana at their northern extent Wei Wang; Wei Wang * 1State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China.2School of Earth, Atmosphere and Environment, Monash University, Melbourne, Victoria 3800, Australia *E-mail: wwz@cug.edu.cn Search for other works by this author on: GSW Google Scholar Peter A. Cawood; Peter A. Cawood 2School of Earth, Atmosphere and Environment, Monash University, Melbourne, Victoria 3800, Australia Search for other works by this author on: GSW Google Scholar Manoj K. Pandit; Manoj K. Pandit 3Department of Geology, University of Rajasthan, Jaipur 302004, India Search for other works by this author on: GSW Google Scholar Jun-Hong Zhao; Jun-Hong Zhao 1State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China. Search for other works by this author on: GSW Google Scholar Jian-Ping Zheng Jian-Ping Zheng 1State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China. Search for other works by this author on: GSW Google Scholar Geology (2019) 47 (4): 308–312. https://doi.org/10.1130/G45745.1 Article history received: 24 Oct 2018 rev-recd: 14 Jan 2019 accepted: 15 Jan 2019 first online: 27 Feb 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Wei Wang, Peter A. Cawood, Manoj K. Pandit, Jun-Hong Zhao, Jian-Ping Zheng; No collision between Eastern and Western Gondwana at their northern extent. Geology 2019;; 47 (4): 308–312. doi: https://doi.org/10.1130/G45745.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Upper Neoproterozoic to lower Paleozoic sedimentary successions in northwestern India are thought to record collision between the continental fragments of Western and Eastern Gondwana, and contain detritus derived from the East African orogen. However, paleocurrent analysis together with U-Pb age distribution and Hf isotopic signatures of detrital zircons from these successions indicate derivation from proximal sources within Eastern Gondwana. Time-equivalent successions from the Qiangtang terrane (Tibetan Plateau) and the northern margin of Neoproterozoic India show a similar provenance record, along with additional input of late Mesoproterozoic and Neoproterozoic detritus from East Antarctica–East India and West Australia. Detritus from the rising East African orogen is abundant in deposits in northern Africa, which constitutes part of Western Gondwana, but absent from equivalent successions in Indian Eastern Gondwana. The consistency in sedimentary provenance of the late Neoproterozoic to early Paleozoic strata in northwestern India, combined with the lack of evidence for deformation or metamorphism since at least ca. 760 Ma, argues against collision between the eastern and western segments of Gondwana in this northern region. These regions remained as passive continental margins separated by a large-scale embayment of the proto-Tethys ocean until late Paleozoic fragmentation of the continental blocks. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Abstract Late Tonian to Cambrian sedimentary sequences in northwestern India and South China provide vital evidence for modeling their paleogeographic linkage, including their juxtaposition and subsequent separation during the transition from the Rodinia to the Gondwana supercontinents. Similarities in lithostratigraphy and detrital zircon U-Pb-Hf-O isotopic characteristics in the late Tonian sedimentary units from both regions underline a common provenance. A substantial decrease in zircon δ18O values from super- to sub-mantle compositions and simultaneous increase in the zircon εHf(t) values in South China and northwestern India for the 800–700 Ma time window suggest a common Neoproterozoic extensional magmatic event, corresponding with the Rodinia breakup. A distinct change in sedimentary provenance is noted during the Cryogenian period. Sedimentation along the northwestern margin of India for the remainder of the Neoproterozoic encompasses large volumes of clastic detritus dominated by old zircon ages, derived inboard from the Indian craton. In contrast, contemporaneous sedimentary units in the Yangtze region of South China are dominated by Neoproterozoic zircons. The detrital zircon age data underline a close paleogeographic linkage between northwestern India and South China (Yangtze and Cathaysia regions) in the Rodinia supercontinent configuration and argue for their separation through continental rifting during the Cryogenian. Northwestern India developed into a passive margin, whereas the South China block partially rifted, rotated, and migrated dextrally along the Gondwana margin toward northeastern India and Western Australia, such that the Cathaysia block continued to receive detritus from Gondwana continental regions.
<p>The late Mesoproterozoic to early Neoproterozoic strata in the Yangtze Block hold a key position in deciphering the tectonic evolution of the South China Block and implicate upon the reconstruction of the Rodinia supercontinent. The sedimentological, geochronologic, and geochemical data on the Kunyang Group, southwestern Yangtze Block, were evaluated for a better understanding of the regional geodynamics and refinement in its paleoposition in the Rodinia supercontinent. Our findings constrain the deposition of the Kunyang Group sediments occurring during 1152 Ma and 1000 Ma, under a stable environment with alternating neritic and littoral facies sedimentation. In contrast, deposition of the Meidang Formation, traditionally thought to represent the upper part of the Kunyang Group, continued up to 866 Ma in an active setting at varying basin depths and hydrodynamic conditions. Moderate to high SiO<sub>2</sub> contents (57.7-95.4 wt%), highly variable K<sub>2</sub>O/Na<sub>2</sub>O ratios (0.01-55.8), and critical trace element abundances (Zr: 57.6-578 ppm, Th: 1.95-28.3 ppm, Sc: 0.75-24.3 ppm), detrital zircon age distribution, sedimentological characteristics, and bimodal magmatism cumulatively underline a transition from continental rift to passive continental margin setting, followed by an active continental marginsetting. The onset of oceanic subduction below the SW-NW margin of the Yangtze Block caused a hiatus in sedimentation, marked by an unconformity between the Kunyang Group and Meidang Formation.</p><p>Paleocurrent data, zircon U-Pb ages, and Lu-Hf isotopic characteristics indicate that the Kunyang Group received detritus from some interior sources and exotic terranes, such as the Gawler Craton in Australia, the Transantarctic Mountains in East Antarctica, and the Ongole domain in the Eastern Dharwar Craton of India. The Yangtze Block was likely located to the west of Australia and East Antarctica and north of India in the Rodinia supercontinent. Paleocurrent data also confirm an external location for the Yangtze Block in the Rodinia paleogeographic configuration.</p>
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
'%3e%3ccircle r='20' fill='%23008'/%3e%3ccircle r='17.5' fill='%23fff'/%3e%3ccircle r='3.5' fill='%23008'/%3e%3cg id='d'%3e%3cg id='c'%3e%3cg id='b'%3e%3cg id='a' fill='%23008'%3e%3ccircle r='.875' transform='rotate(7.5 -8.75 133.5)'/%3e%3cpath d='M0 17.5.6 7 0 2l-.6 5L0 17.5z'/%3e%3c/g%3e%3cuse xlink:href='%23a' transform='rotate(15)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(30)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(60)'/%3e%3c/g%3e%3cuse xlink:href='%23d' transform='rotate(120)'/%3e%3cuse xlink:href='%23d' transform='rotate(-120)'/%3e%3c/g%3e%3c/svg%3e)
