New detrital zircon U–Pb insights on the palaeogeographic origin of the central Sanandaj–Sirjan zone, Iran

Abstract New detrital U–Pb zircon ages from the Sanandaj–Sirjan metamorphic zone in the Zagros orogenic belt allow discussion of models of the late Neoproterozoic to early Palaeozoic plate tectonic evolution and position of the Iranian microcontinent within a global framework. A total of 194 valid age values from 362 zircon grains were obtained from three garnet-micaschist samples. The most abundant detrital zircon population included Ediacaran ages, with the main age peak at 0.60 Ga. Other significant age peaks are at c. 0.64–0.78 Ga, 0.80–0.91 Ga, 0.94–1.1 Ga, 1.8–2.0 Ga and 2.1–2.5 Ga. The various Palaeozoic zircon age peaks could be explained by sediment supply from sources within the Iranian microcontinent. However, Precambrian ages were found, implying a non-Iranian provenance or recycling of upper Ediacaran–Palaeozoic clastic rocks. Trace-element geochemical fingerprints show that most detrital zircons were sourced from continental magmatic settings. In this study, the late Grenvillian age population at c. 0.94–1.1 Ga is used to unravel the palaeogeographic origin of the Sanandaj–Sirjan metamorphic zone. This Grenvillian detrital age population relates to the ‘Gondwana superfan’ sediments, as found in many Gondwana-derived terranes within the European Variscides and Turkish terranes, but also to units further east, e.g. in the South China block. Biogeographic evidence proves that the Iranian microcontinent developed on the same North Gondwana margin extending from the South China block via Iran further to the west.

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Detrital zircon geochronology of pre-Cretaceous strata: tectonic implications for the Jiangnan Orogen, South China

Geological Magazine ◽

10.1017/s0016756813001003 ◽

2014 ◽

Vol 151 (6) ◽

pp. 975-995 ◽

Cited By ~ 22

Author(s):

JINBAO SU ◽

SHUWEN DONG ◽

YUEQIAO ZHANG ◽

YONG LI ◽

XUANHUA CHEN ◽

...

Keyword(s):

South China ◽

North China ◽

Seismic Profile ◽

Upper Jurassic ◽

Detrital Zircons ◽

South China Block ◽

Yangtze Block ◽

The South ◽

Provenance Data ◽

Cathaysia Block

AbstractFifteen sandstone samples taken from pre-Cretaceous strata of the Yangtze Block are analysed to constrain the evolution of the South China Block, especially the assembly between the Yangtze and Cathaysia blocks. The results show that the maximum depositional age of the Neoproterozoic Lengjiaxi Group adjacent to the Cathaysia Block isc. 830 Ma, differing from that of the Kunyang and Dahongshan groups (> 960 Ma) on the southwestern margin of the Yangtze Block. The detrital zircons from Palaeozoic samples from the Yangtze Block have similar age populations to those in the Cathaysia Block, and they may originate from the Cathaysia Block according to palaeogeographic, palaeocurrent and former research data. The detrital zircons of Middle–Upper Jurassic sandstones in the southwestern and central Yangtze Block yield dominant age populations at 2.0–1.7 Ga and subordinate groups of 2.6–2.4 Ga, 0.8–0.7 Ga and 0.6–0.4 Ga. The Upper Triassic strata may be derived from the southern Yangtze and North China blocks due to the collisions between the Indosina, South China and North China blocks, whereas the Jurassic sediments may be partly derived from uplift and erosion of the Jiangnan Orogen due to an intracontinental orogeny induced by Pacific subduction towards the Eurasia Plate. The detrital age spectra and provenance data for basement in the South China Block are analysed and compared with each other. The South China Block has affinity with Australia not only in the Columbia supercontinent but also in the Rodinia supercontinent. We infer the existence of an ancient orogen under the western Jiangnan Orogen, which may have occurred during the Columbia age, earlier than the Sibao orogeny. This is supported by seismic profile proof from the SinoProbe.

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Subduction polarity of the Ailaoshan Ocean (eastern Paleotethys): Constraints from detrital zircon U-Pb and Hf-O isotopes for the Longtan Formation

Geological Society of America Bulletin ◽

10.1130/b35294.1 ◽

2019 ◽

Vol 132 (5-6) ◽

pp. 987-996

Author(s):

Xiao-Ping Xia ◽

Jian Xu ◽

Chao Huang ◽

Xiaoping Long ◽

Meiling Zhou

Keyword(s):

South China ◽

Detrital Zircon ◽

South China Block ◽

The South ◽

Forearc Basin ◽

Isotopic Signatures ◽

Northeastern Japan ◽

O Isotopes ◽

A Minor ◽

Back Arc

Abstract The Paleotethys Ailaoshan Ocean separated the South China and Indochina blocks during the late Paleozoic. Uncertainty remains regarding subduction of this ocean—whether it was subducted eastward beneath the South China block or westward beneath the Indochina block. In this study, we present new detrital zircon U-Pb age, and Hf and O isotope data from the Longtan Formation, which was recognized to be deposited before the ocean closed. Our results show that the formation can be divided into three units: Unit 1 is distributed west of the suture and dominates the area; it contains major age peaks at 290–250 Ma and minor multiple old age peaks. Unit 2 consists of a minor distribution west of the suture, and it shows a dominant 250 Ma age peak; old zircons are very few or not present. Their Hf and O isotopic signatures are similar to those of unit 1. Unit 3 is distributed east of the suture and is characterized by a single distinct ca. 240 Ma age peak with almost no Precambrian zircons. We interpret that units 1 and 2 were likely deposited in a back-arc and forearc basin, respectively, and a volcanic arc developed on the eastern margin of the Indochina block, similar to the present-day northeastern Japan arc. Meanwhile, unit 3 was likely deposited in a forearc basin on the western margin of the South China block. Therefore, the Ailaoshan Ocean may undergone bipolar subduction both westward and eastward beneath the Indochina and South China blocks, respectively.

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Paleo - position of the South China Craton in the Rodinia Supercontinent: Evidence from the U - Pb age and Hf isotope of detrital zircon from the Nam Co Complex

Journal of Mining and Earth Sciences ◽

10.46326/jmes.2021.62(3).01 ◽

2021 ◽

Vol 62 (3) ◽

pp. 1-12

Author(s):

Keyword(s):

South China ◽

Detrital Zircon ◽

Age Distribution ◽

Detrital Zircons ◽

East Antarctica ◽

Hf Isotope ◽

The South ◽

Nam Co ◽

Rodinia Supercontinent ◽

South China Craton

To constrain the paleo - positions of the South China Cratons in the Rodinia Supercontinent during the Neoproterozoic, the in - situ U - Pb dating, and Hf isotope analysis of the detrital zircon from the Nam Co Complex, Song Ma Suture zone, northwestern Vietnam was performed. The U - Pb isotopic dating on detrital zircons shows that the Nam Co Complex demonstrates the major population (>50%) of around ~850 Ma while the minor population is scattered between ~1.2÷3.0 Ga. The Neoproterozoic age spectrum exhibits a large range of the εHf(t) from strongly negative to positive values ( - 17.418022÷ 14.600527), indicating that the source of the magma for this age range has been not only derived from reworking of the Archean basement rocks, but also generated from the juvenile material. The U - Pb age distribution patterns and Hf isotopic data of the detrital zircon in the Nam Co Complex are compatible with those of the South China Craton rather than those of the Indochina Craton. The data also indicate that sedimentary protoliths of the Nam Co Complex were deposited in a convergent - related basin along the southwestern margin of the South China Craton during the Neoproterozoic. Combined with the similarities of the detrital zircon age between western Cathaysia, Indochina, East Antarctica and East India, it is proved that the South China Craton was situated at the margin of the Rodinia Supercontinent and in close proximity to the Indochina, East Antarctica and East India.

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U-Pb ages, trace elements and Hf isotopes of detrital zircons from the late Permian-early Triassic sedimentary succession in the northern Yangtze Block, South China: Implications for the reconstruction of the South China Block in Pangea

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2020.104609 ◽

2020 ◽

pp. 104609 ◽

Cited By ~ 1

Author(s):

Binsong Zheng ◽

Chuanlong Mou ◽

Xiuping Wang ◽

Hongde Chen

Keyword(s):

Trace Elements ◽

South China ◽

Detrital Zircons ◽

Hf Isotopes ◽

Early Triassic ◽

South China Block ◽

Late Permian ◽

Yangtze Block ◽

The South ◽

Sedimentary Succession

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Detrital zircon evidence for the linkage of the South China block with Gondwanaland in early Palaeozoic time

Geological Magazine ◽

10.1017/s0016756812000404 ◽

2012 ◽

Vol 149 (6) ◽

pp. 1124-1131 ◽

Cited By ~ 25

Author(s):

LIANG DUAN ◽

QING-REN MENG ◽

GUO-LI WU ◽

SHOU-XIAN MA ◽

LIN LI

Keyword(s):

South China ◽

Detrital Zircon ◽

Age Distribution ◽

South China Block ◽

The South ◽

Crustal Rocks ◽

Pan African ◽

Continental Block ◽

Mixed Origin ◽

Early Palaeozoic

AbstractLA-ICP-MS U–Pb dating of Lower Devonian detrital zircon samples from three representative sections in the South China block yields dominant Grenvillian and Pan-African populations, similar to the age distribution of early Palaeozoic samples from Gondwana, the Tethyan Himalaya and West Australia, in particular. Hf isotopic compositions indicate the contributions of juvenile crust at 1.6 Ga and 2.5 Ga, and bear a resemblance to their counterparts from SE Australia and West Antarctica, revealing the mixed origin of the Pan-African and Grenvillian grains from juvenile magmas and melting of pre-existing crustal rocks. These results suggest that the South China block should be considered an integral part of East Gondwana in early Palaeozoic time, rather than a discrete continental block in the Palaeo-Pacific or a fragment of Laurentia.

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