Late Cretaceous hydrous melting and reworking of juvenile lower crust of the eastern Gangdese magmatic arc, southern Tibet

2021 ◽  
Author(s):  
Huixia Ding ◽  
Zeming Zhang ◽  
Matthew J. Kohn
Keyword(s):  
Late Cretaceous ◽  
Lower Crust ◽  
Southern Tibet ◽  
Magmatic Arc ◽  
Hydrous Melting

scholarly journals Formation and composition of the Late Cretaceous Gangdese arc lower crust in southern Tibet

2020 ◽  
Vol 175 (6) ◽  
Author(s):  
Liang Guo ◽  
Oliver Jagoutz ◽  
William J. Shinevar ◽  
Hong-Fei Zhang
Keyword(s):  
Late Cretaceous ◽  
Lower Crust ◽  
Southern Tibet

Early Cenozoic partial melting of meta-sedimentary rocks of the eastern Gangdese arc, southern Tibet, and its contribution to syn-collisional magmatism

2021 ◽  
Author(s):  
Yuan-Yuan Jiang ◽  
Ze-Ming Zhang ◽  
Richard M. Palin ◽  
Hui-Xia Ding ◽  
Xuan-Xue Mo
Keyword(s):  
Partial Melting ◽  
Lower Crust ◽  
Sedimentary Rocks ◽  
Late Carboniferous ◽  
Southern Tibet ◽  
Magmatic Arc ◽  
Magmatic Rocks ◽  
Deep Crust ◽  
Juvenile Crust ◽  
Early Cenozoic

Continental magmatic arcs are characterized by the accretion of voluminous mantle-derived magmatic rocks and the growth of juvenile crust. However, significant volumes of meta-sedimentary rocks occur in the middle and lower arc crust, and the contributions of these rocks to the evolution of arc crust remain unclear. In this paper, we conduct a systematic study of petrology, geochronology, and geochemistry of migmatitic paragneisses from the eastern Gangdese magmatic arc, southern Tibet. The results show that the paragneisses were derived from late Carboniferous greywacke, and underwent an early Cenozoic (69−41 Ma) upper amphibolite-facies metamorphism and partial melting at pressure-temperature conditions of ∼11 kbar and ∼740 °C, and generated granitic melts with enriched Hf isotopic compositions (anatectic zircon εHf(t) = −10.57 to +0.78). Combined with the existing results, we conclude that the widely distributed meta-sedimentary rocks in the eastern Gangdese arc deep crust have the same protolith ages of late Carboniferous, and record northwestward-decreasing metamorphic conditions. We consider that the deeply buried sedimentary rocks resulted in the compositional change of juvenile lower crust from mafic to felsic and the formation of syn-collisional S-type granitoids. The mixing of melts derived from mantle, juvenile lower crust, and ancient crustal materials resulted in the isotopic enrichment of the syn-collisional arc-type magmatic rocks of the Gangdese arc. We suggest that crustal shortening and underthrusting, and the accretion of mantle-derived magma during the Indo-Asian collision transported the supracrustal rocks to the deep crust of the Gangdese arc.

The lower crust of the Gangdese magmatic arc, southern Tibet, implication for the growth of continental crust

2020 ◽  
Vol 77 ◽  
pp. 136-146 ◽  
Author(s):  
Zeming Zhang ◽  
Huixia Ding ◽  
Richard M. Palin ◽  
Xin Dong ◽  
Zuolin Tian ◽  
...  
Keyword(s):  
Continental Crust ◽  
Lower Crust ◽  
Southern Tibet ◽  
Magmatic Arc

scholarly journals Supplemental Material: The Mesozoic magmatic, metamorphic, and tectonic evolution of the eastern Gangdese magmatic arc, southern Tibet

2021 ◽  
Author(s):  
Zeming Zhang
Keyword(s):  
Trace Element ◽  
Late Cretaceous ◽  
Tectonic Evolution ◽  
Chemical Compositions ◽  
Isotopic Data ◽  
Southern Tibet ◽  
Magmatic Arc ◽  
Magmatic Rocks

Table S1: Major features of the reported Jurassic magmatic rocks of the eastern Gangdese arc; Table S2: Zircon U-Pb dating and trace element (in ppm) data of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S3: Zircon Hf isotopic data of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S4: Whole-rock chemical compositions of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S5: Whole-rock chemical compositions of the Mesozoic magmatic rocks of the eastern Gangdese arc; Table S6: Whole-rock SiO2 and Cu concentrations of the Late Cretaceous magmatic rocks of the eastern Gangdese arc.

scholarly journals Supplemental Material: The Mesozoic magmatic, metamorphic, and tectonic evolution of the eastern Gangdese magmatic arc, southern Tibet

2021 ◽  
Author(s):  
Zeming Zhang
Keyword(s):  
Trace Element ◽  
Late Cretaceous ◽  
Tectonic Evolution ◽  
Chemical Compositions ◽  
Isotopic Data ◽  
Southern Tibet ◽  
Magmatic Arc ◽  
Magmatic Rocks

Table S1: Major features of the reported Jurassic magmatic rocks of the eastern Gangdese arc; Table S2: Zircon U-Pb dating and trace element (in ppm) data of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S3: Zircon Hf isotopic data of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S4: Whole-rock chemical compositions of the studied Jurassic magmatic rocks of the eastern Gangdese arc; Table S5: Whole-rock chemical compositions of the Mesozoic magmatic rocks of the eastern Gangdese arc; Table S6: Whole-rock SiO2 and Cu concentrations of the Late Cretaceous magmatic rocks of the eastern Gangdese arc.

STRAIN ACCOMMODATION AND 3D KINEMATICS OF TRANSPRESSIONAL FLOW WITHIN THE LOWER CRUST OF A CRETACEOUS MAGMATIC ARC IN FIORDLAND NEW ZEALAND

2018 ◽  
Author(s):  
Griffin A. Moyer ◽  
◽  
Jesse Lee ◽  
Christopher Eddy ◽  
Elena A. Miranda ◽  
...  
Keyword(s):  
New Zealand ◽  
Lower Crust ◽  
3D Kinematics ◽  
Magmatic Arc

GARNET SM-ND AGE CONSTRAINTS ON GRANULITE METAMORPHISM IN THE LOWER CRUST OF THE FIORDLAND MAGMATIC ARC, NEW ZEALAND

2018 ◽  
Author(s):  
Ryan L. Rogers ◽  
◽  
James W. Yelverton ◽  
Harold H. Stowell ◽  
Elizabeth M. Bollen ◽  
...  
Keyword(s):  
New Zealand ◽  
Lower Crust ◽  
Magmatic Arc ◽  
Granulite Metamorphism ◽  
Age Constraints

scholarly journals Petrogenesis and Geodynamic Implications of Miocene Felsic Magmatic Rocks in the Wuyu Basin, Southern Gangdese Belt, Qinghai-Tibet Plateau

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 655
Author(s):  
Hanzhi Chen ◽  
Mingcai Hou ◽  
Fuhao Xiong ◽  
Hongwei Tang ◽  
Gangqiang Shao
Keyword(s):  
Lower Crust ◽  
Volcanic Rocks ◽  
Tibet Plateau ◽  
Southern Tibet ◽  
Mixed Product ◽  
Good Opportunity ◽  
Magmatic Rocks ◽  
Adakitic Rocks ◽  
Felsic Volcanic ◽  
Qinghai Tibet Plateau

Miocene felsic magmatic rocks with high Sr/Y ratios are widely distributed throughout the Gangdese belt of southern Tibet. These provide a good opportunity to explore the magmatic process and deep dynamic mechanisms that occurred after collision between the Indo and the Asian plates. In this paper, felsic volcanic rocks from the Zongdangcun Formation in the Wuyu Basin in the central part of the southern Gangdese belt are used to disclose their origin. Zircon U-Pb geochronology analysis shows that the felsic magmatism occurred at ca. 10.3 ± 0.2 Ma, indicating that the Zongdangcun Formation formed during the Miocene. Most of these felsic magmatic rocks plot in the rhyolite area in the TAS diagram. The rhyolite specimens from the Zongdangcun Formation have the characteristics of high SiO2 (>64%), K2O, SiO2, and Sr contents, a low Y content and a high Sr/Y ratio, and the rocks are rich in LREE and depleted in HREE, showing geochemical affinity to adakitic rocks. The rocks have an enriched Sr-Nd isotopic composition (εNd(t) = −6.76 to −6.68, (87Sr/86Sr)i = 0.7082–0.7088), which is similar to the mixed product of the juvenile Lhasa lower continental crust and the ancient Indian crust. The Hf isotopes of zircon define a wide compositional range (εHf(t) = −4.19 to 6.72) with predominant enriched signatures. The Miocene-aged crustal thickness in southern Tibet, calculated on the basis of the Sr/Y and (La/Yb)N ratios was approximately 60–80 km, which is consistent with the thickening of the Qinghai-Tibet Plateau. The origin of Miocene felsic magmatic rocks with high Sr/Y ratios in the middle section of the Gangdese belt likely involved a partial melting of the thickened lower crust, essentially formed by the lower crust of the Lhasa block, with minor contribution from the ancient Indian crust. After comprehensively analyzing the post-collisional high Sr/Y magmatic rocks (33–8 Ma) collected from the southern margin of the Gangdese belt, we propose that the front edge tearing and segmented subduction of the Indian continental slab may be the major factor driving the east-west trending compositional changes of the Miocene adakitic rocks in southern Tibet.

The Late Cretaceous magmatic arc of the south Aegean: Geodynamic implications from petrological and geochemical studies of granitoids from Anafi island (Cyclades – Greece)

2021 ◽  
pp. 1-24
Author(s):  
Petros Koutsovitis ◽  
Konstantinos Soukis ◽  
Panagiotis Voudouris ◽  
Stylianos Lozios ◽  
Theodoros Ntaflos ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
The South ◽  
Magmatic Arc ◽  
Geochemical Studies

Mesozoic Tectonic Setting of SE Sundaland After Magmatism and Suture Evidences in JS-1 Ridge Area

2021 ◽  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Tectonic Setting ◽  
Plate Boundary ◽  
Early Jurassic ◽  
The South ◽  
Magmatic Arc ◽  
Plate Convergence ◽  
Ridge Area ◽  
Cretaceous Subduction

Mesozoic plate convergence in SE Sundaland has been a source of debate for decades. A determination of plate convergence boundaries and timing have been explained in many publications, but not all boundaries were associated with magmatism. Through integration of both plate configurations and magmatic deposits, the basement can be accurately characterized over time and areal extents. This paper will discuss Cretaceous subductions and magmatic arc trends in SE Sundaland area with additional evidence found in JS-1 Ridge. At least three subduction trends are captured during the Mesozoic in the study area: 1) Early Jurassic – Early Cretaceous trend of Meratus, 2) Early Cretaceous trend of Bantimala and 3) Late Cretaceous trend in the southernmost study area. The Early Jurassic – Early Cretaceous subduction occurred along the South and East boundary of Sundaland (SW Borneo terrane) and passes through the Meratus area. The Early Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo and Paternoster terranes) and pass through the Bantimala area. The Late Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo, Paternoster and SE Java – South Sulawesi terranes), but is slightly shifted to the South approaching the Oligocene – Recent subduction zone. Magmatic arc trends can also be generally grouped into three periods, with each period corresponds to the subduction processes at the time. The first magmatic arc (Early Jurassic – Early Cretaceous) is present in core of SW Borneo terrane and partly produces the Schwaner Magmatism. The second Cretaceous magmatic arc (Early Cretaceous) trend is present in the SW Borneo terrane but is slightly shifted southeastward It is responsible for magmatism in North Java offshore, northern JS-1 Ridge and Meratus areas. The third magmatic arc trend is formed by Late Cretaceous volcanic rocks in Luk Ulo, the southern JS-1 Ridge and the eastern Makassar Strait areas. These all occur during the same time within the Cretaceous magmatic arc. Though a mélange rock sample has not been found in JS-1 Ridge area, there is evidence of an accretionary prism in the area as evidenced by the geometry observed on a new 3D seismic dataset. Based on the structural trend of Meratus (NNE-SSW) coupled with the regional plate boundary understanding, this suggests that both Meratus & JS-1 Ridge are part of the same suture zone between SW Borneo and Paternoster terranes. The gradual age transition observed in the JS-1 Ridge area suggests a southward shift of the magmatic arc during Early Cretaceous to Late Cretaceous times.

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