scholarly journals Provenance, depositional setting, and crustal evolution of the Cathaysia Block, South China: Insights from detrital zircon U–Pb geochronology and geochemistry of clastic rocks

2018 ◽  
Vol 54 (2) ◽  
pp. 897-912 ◽  
Author(s):  
Chen Xiong ◽  
Hongde Chen ◽  
Yaoling Niu ◽  
Anqing Chen ◽  
Chenggong Zhang ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Crustal Evolution ◽  
Clastic Rocks ◽  
Cathaysia Block ◽  
Depositional Setting

The Mesoproterozoic Baoban Complex, South China: A missing fragment of western Laurentian lithosphere

2019 ◽  
Vol 132 (7-8) ◽  
pp. 1404-1418 ◽  
Author(s):  
Ya-Jun Xu ◽  
Peter A. Cawood ◽  
Hang-Chuan Zhang ◽  
Jian-Wei Zi ◽  
Jin-Bo Zhou ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Hainan Island ◽  
New Age ◽  
Metasedimentary Rocks ◽  
Basement Rocks ◽  
Cathaysia Block ◽  
Two Peaks

Abstract New age data for the Baoban Complex, South China establishes that it lay outboard of western Laurentia in the early Mesoproterozoic but was not part of the Cathaysia Block, with which it is traditional linked, until the mid-Paleozoic. Our geochronology data for detrital zircon and authigenic monazite grains from metasedimentary rocks indicate accumulation between ca. 1.55 Ga and 1.45 Ga for the Gezhencun succession of the Baoban Complex and ca. 1.45 Ga and 1.30 Ga for the Ewenling succession. The former unit is dominated by detrital zircon populations between 1900 Ma and 1500 Ma with two peaks at 1780 Ma and 1580 Ma. The Ewenling succession has detrital zircon peaks at 1720 Ma and 1450 Ma. Newly discovered gneissic granites were emplaced at 1550 Ma and intruded by 1450 Ma leucogranite dykes that are coeval with 1460–1430 Ma bimodal magmatism. The whole Baoban Complex was metamorphosed over the range of 1.3–0.9 Ga based on ages of authigenic zircon and monazite. Depositional ages of metasedimentary rocks are coeval with successions of the Belt-Purcell Basin, western Laurentia. Detrital zircon from the two regions have similar age populations and Lu-Hf compositions, and display a synchronous provenance shift at ca. 1.45 Ga. Basement lithologies on Hainan Island range in age from ca. 1.55–1.43 Ga and underwent metamorphism during 1.3–0.9 Ga. This is younger than basement rocks on the mainland of the Cathaysia Block in South China, suggesting the two regions are spatially unrelated at this time and hence the Mesoproterozoic record of the island cannot constrain the location of the Cathaysia Block in the Nuna and Rodinia supercontinents.

Provenance and tectonic setting of the Triassic clastic deposits in the Napo basin, South China: evidence from petrography, whole-rock geochemistry and detrital zircon U–Pb geochronology

2021 ◽  
pp. 1-20
Author(s):  
Lei Xia ◽  
Quan-Ren Yan ◽  
Zhong-Jin Xiang ◽  
Hong-Bo Zheng ◽  
Quan-Lin Hou ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Middle Triassic ◽  
Tectonic Setting ◽  
Detrital Zircons ◽  
Island Arc ◽  
Late Permian ◽  
Magmatic Arc ◽  
Clastic Rocks ◽  
Arc Setting

Abstract The provenance and tectonic setting of the Lower–Middle Triassic clastic sediments from the Napo basin, South China, have been examined here using detrital modes, whole-rock geochemistry and detrital zircon U–Pb ages. Field investigations indicate that these sediments consist of fan delta, slope and turbidity fan facies with dominantly southward palaeocurrent directions. Detrital modes and geochemical characteristics of the clastic rocks indicate that they were derived from mixed magmatic arc and Palaeozoic successions in a continental island arc setting, with no significant sediment recycling. The U–Pb age spectra of sandstone detrital zircons from different stratigraphic positions are similar, with one major group (300–230 Ma), two subordinate groups (400–320 Ma and 480–420 Ma, respectively) and two scattered groups (1200–800 Ma and 2000–1700 Ma, respectively). Thus, we consider that the north late Permian – Middle Triassic volcanic rocks and the uplifted Palaeozoic sedimentary/volcanic sequences constituted the predominant sources. The detritus derived from the late Permian Emeishan mafic rocks is subordinate and limited. The pre-Devonian zircons are likely sedimentary-recycled or magmatic-captured instead of directly derived from the early Palaeozoic orogen (e.g. Yunkai massif) and Neoproterozoic Jiangnan orogen because of the topographic barrier of a magmatic arc and carbonate platform. Considering the spatial and temporal distribution characteristics of the volcanic arc and ophiolite, we suggest that the Triassic Napo basin was a fore-arc basin within a continental island arc setting, which developed in response to the northward subduction of the Babu–Cao Bang branch ocean beneath the South China Block.

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

2021 ◽  
pp. 1-22
Author(s):  
Farzaneh Shakerardakani ◽  
Franz Neubauer ◽  
Xiaoming Liu ◽  
Yunpeng Dong ◽  
Behzad Monfaredi ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Sediment Supply ◽  
Detrital Zircons ◽  
South China Block ◽  
The South ◽  
Clastic Rocks ◽  
Gondwana Margin ◽  
Metamorphic Zone ◽  
North Gondwana

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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