Linking the Indochina block and Gondwana during the Early Paleozoic: Evidence from U–Pb ages and Hf isotopes of detrital zircons

2013 ◽  
Vol 586 ◽  
pp. 145-159 ◽  
Author(s):  
Tadashi Usuki ◽  
Ching-Ying Lan ◽  
Kuo-Lung Wang ◽  
Han-Yi Chiu
Author(s):  
Bingshuang Zhao ◽  
Xiaoping Long ◽  
Jin Luo ◽  
Yunpeng Dong ◽  
Caiyun Lan ◽  
...  

The crustal evolution of the Yangtze block and its tectonic affinity to other continents of Rodinia and subsequent Gondwana have not been well constrained. Here, we present new U-Pb ages and Hf isotopes of detrital zircons from the late Neoproterozoic to early Paleozoic sedimentary rocks in the northwestern margin of the Yangtze block to provide critical constraints on their provenance and tectonic settings. The detrital zircons of two late Neoproterozoic samples have a small range of ages (0.87−0.67 Ga) with a dominant age peak at 0.73 Ga, which were likely derived from the Hannan-Micangshan arc in the northwestern margin of the Yangtze block. In addition, the cumulative distribution curves from the difference between the depositional age and the crystalline age (CA−DA) together with the mostly positive εHf(t) values of these zircon crystals (−6.8 to +10.7, ∼90% zircon grains with εHf[t] > 0) suggest these samples were deposited in a convergent setting during the late Neoproterozoic. In contrast, the Cambrian−Silurian sediments share a similar detrital zircon age spectrum that is dominated by Grenvillian ages (1.11−0.72 Ga), with minor late Paleoproterozoic (ca. 2.31−1.71 Ga), Mesoarchean to Neoarchean (3.16−2.69 Ga), and latest Archean to early Paleoproterozoic (2.57−2.38 Ga) populations, suggesting a significant change in the sedimentary provenance and tectonic setting from a convergent setting after the breakup of Rodinia to an extensional setting during the assembly of Gondwana. However, the presence of abundant Grenvillian and Neoarchean ages, along with their moderately to highly rounded shapes, indicates a possible sedimentary provenance from exotic continental terrane(s). Considering the potential source areas around the Yangtze block when it was a part of Rodinia or Gondwana, we suggest that the source of these early Paleozoic sediments had typical Gondwana affinities, such as the Himalaya, north India, and Tarim, which is also supported by their stratigraphic similarity, newly published paleomagnetic data, and tectono-thermal events in the northern fragments of Gondwana. This implies that after prolonged subduction in the Neoproterozoic, the northwestern margin of the Yangtze block began to be incorporated into the assembly of Gondwana and then accept sediments from the northern margin of Gondwanaland in a passive continental margin setting.


Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 1-10
Author(s):  
Qian Liu ◽  
Guochun Zhao ◽  
Jianhua Li ◽  
Jinlong Yao ◽  
Yigui Han ◽  
...  

Abstract The location of the Tarim craton during the assembly and breakup of the Rodinia supercontinent remains enigmatic, with some models advocating a Tarim-Australia connection and others a location at the heart of the unified Rodinia supercontinent between Australia and Laurentia. In this study, our new zircon U-Pb dating results suggest that middle Neoproterozoic sedimentary rocks in the Altyn Tagh orogen of the southeastern Tarim craton were deposited between ca. 880 and 760 Ma in a rifting-related setting slightly prior to the breakup of Rodinia at ca. 750 Ma. A compilation of existing Neoproterozoic geological records also indicates that the Altyn Tagh orogen of the southeastern Tarim craton underwent collision at ca. 1.0-0.9 Ga and rifting at ca. 850-600 Ma related to the assembly and breakup of Rodinia. Furthermore, in order to establish the paleoposition of the Tarim craton with respect to Rodinia, available detrital zircon U-Pb ages and Hf isotopes from Meso- to Neoproterozoic sedimentary rocks were compiled. Comparable detrital zircon ages (at ca. 0.9, 1.3-1.1, and 1.7 Ga) and Hf isotopes indicate a close linkage among rocks of the southeastern Tarim craton, Cathaysia, and North India but exclude a northern or western Australian affinity. In addition, detrital zircons from the northern Tarim craton exhibit a prominent age peak at ca. 830 Ma with minor spectra at ca. 1.9 and 2.5 Ga but lack Mesoproterozoic ages, comparable to the northern and western Yangtze block. Together with comparable geological responses to the assembly and breakup of the Rodinia supercontinent, we offer a new perspective of the location of the Tarim craton between South China and North India in the periphery of Rodinia.


Author(s):  
Moonsup Cho ◽  
Wonseok Cheong ◽  
W.G. Ernst ◽  
Yoonsup Kim ◽  
Keewook Yi

The early Paleozoic paleogeography of East Gondwanan terranes, including the North China Craton (NCC), is contentious, primarily reflecting the paucity of integrated geochronological, biogeographic, and tectonic data sets. Our new sensitive high-resolution ion microprobe data from 14 sandstones of the Taebaeksan Basin, Korea, indicate that its platform shelf sequences, typified by trilobite faunal assemblages diagnostic of the NCC, record the vestige of coeval arc magmatism. Detrital zircons analyzed from the sandstones yielded Eoarchean to Early Ordovician ages, which define three distinct types of distribution patterns characterized by: (1) double peaks at ca. 1.85 Ga and 2.50 Ga diagnostic of basement rocks in the NCC; (2) minor peaks at ca. 1.75, 1.6, and 1.2−1.1 Ga in addition to double peaks; and finally (3) a scattered array of late Paleoproterozoic to Neoproterozoic zircons lacking double peaks. The marked contrasts among the three types reflect significant changes in provenance, most likely linked to variations in paleo-water depths during the “Sauk” transgression. Longshore- or onshore-directed currents, associated with an increase in water depth, apparently brought outboard oceanic detritus and benthic trilobites into the relatively flat outer shelf of the Taebaeksan Basin. As a result, fine-grained sandstones received a large amount of detritus from distal sources, yielding mixed signatures in zircon age patterns and trilobite assemblages. Excluding the basal sandstone-conglomerate unit, five siliciclastic formations contain syndepositional zircon populations, and their weighted mean 206Pb/238U ages decrease upsection from 512 ± 5 Ma to 483 ± 2 Ma, indicating a sedimentary influx from contemporaneous volcanic activity. In conjunction with arc-related bulk-rock geochemistry and juvenile Nd isotopic signature, early Paleozoic detrital zircons likely represent the first-cycle detritus supplied for ∼30 m.y. from the proto-Japan arc that initially formed at ca. 520 Ma. Together with the occurrence of ca. 700−500 Ma detrital Pacific Gondwana zircons in fine-grained sandstones, Paleozoic arc-sourced detritus suggests that the Korean Peninsula was paleogeographically linked to an ancient convergent margin, perhaps extending from the Terra Australis orogen.


2020 ◽  
Author(s):  
Qian Liu

<p>Locating Tarim during assembly and breakup of Supercontinent Rodinia remains enigmatic, with different models advocating a Tarim-Australia linkage or a location between Australia and Laurentia at the heart of unified Rodinia. In this study, zircon U-Pb dating results first revealed middle Neoproterozoic sedimentary rocks in the Altyn Tagh orogen, southeastern Tarim. These sedimentary rocks were deposited between ca. 880 and 750 Ma in a rifting-related setting slightly prior to breakup of Rodinia at ca. 750 Ma. A compilation of Neoproterozoic geological records indicates that the Altyn Tagh orogen in southeastern Tarim underwent ca. 1.0-0.9 Ga collision and ca. 850-600 Ma rifting related to assembly and breakup of Rodinia, respectively. In order to place Tarim in Rodinia, available detrital zircon U-Pb ages and Hf isotopes from Meso- to Neoproterozoic sedimentary rocks in relevant Rodinia blocks are compiled. Comparable detrital zircon ages (at ca. 0.9, 1.3-1.1, and 1.7 Ga) and Hf isotopes indicate a close linkage among southeastern Tarim, Cathaysia, and North India, but rule out a North or West Australian affinity for Tarim. In addition, detrital zircons from northern Tarim exhibit a prominent age peak at ca. 830 Ma with minor spectra at ca. 1.9 and 2.5 Ga but lack Mesoproterozoic ages, which are comparable to those from northern and western Yangtze. Together with comparable geological responses to assembly and breakup of Rodinia, a new Tarim-South China-North India connection is inferred in the periphery of Rodinia.</p>


2017 ◽  
Vol 298 ◽  
pp. 490-511 ◽  
Author(s):  
Xiao-Peng Dong ◽  
Jian-Min Hu ◽  
Zhen-Hong Li ◽  
Yi Zhao ◽  
Wang-Bin Gong ◽  
...  

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