scholarly journals Supplemental Material: Three stages of arc migration in the Carboniferous-Triassic in northern Qiangtang, central Tibet, China: Ridge subduction and asynchronous slab rollback of the Jinsha Paleotethys

2021 ◽  
Author(s):  
Yin Liu ◽  
W.J. Xiao ◽  
et al.
Keyword(s):  
Geochemical Data ◽  
Data Set ◽  
Ridge Subduction ◽  
Data Table ◽  
Magmatic Rocks ◽  
Slab Rollback ◽  
Three Stages ◽  
Zircon Morphology ◽  
Central Tibet ◽  
Qiangtang Terrane

Sampling details (Table S1), zircon geochronological data (Table S2), geochemical data (Table S3), and a summary of zircon morphology and geochronology (Table S4) for Carboniferous-Triassic samples from the northern Qiangtang terrane. Geochemical data set of Carboniferous-Triassic magmatic rocks from the northern Qiangtang terrane (Table S5).

scholarly journals Supplemental Material: Three stages of arc migration in the Carboniferous-Triassic in northern Qiangtang, central Tibet, China: Ridge subduction and asynchronous slab rollback of the Jinsha Paleotethys

2021 ◽  
Author(s):  
Yin Liu ◽  
W.J. Xiao ◽  
et al.
Keyword(s):  
Geochemical Data ◽  
Data Set ◽  
Ridge Subduction ◽  
Data Table ◽  
Magmatic Rocks ◽  
Slab Rollback ◽  
Three Stages ◽  
Zircon Morphology ◽  
Central Tibet ◽  
Qiangtang Terrane

Sampling details (Table S1), zircon geochronological data (Table S2), geochemical data (Table S3), and a summary of zircon morphology and geochronology (Table S4) for Carboniferous-Triassic samples from the northern Qiangtang terrane. Geochemical data set of Carboniferous-Triassic magmatic rocks from the northern Qiangtang terrane (Table S5).

Three stages of arc migration in the Carboniferous-Triassic in northern Qiangtang, central Tibet, China: Ridge subduction and asynchronous slab rollback of the Jinsha Paleotethys

2021 ◽  
Author(s):  
Yin Liu ◽  
Wenjiao Xiao ◽  
Brian F. Windley ◽  
Kefa Zhou ◽  
Rongshe Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Volcanic Rocks ◽  
Late Triassic ◽  
Geochemical Data ◽  
The Tibetan Plateau ◽  
Ridge Subduction ◽  
Temporal Relationships ◽  
Slab Rollback ◽  
Geodynamic Processes ◽  
Central Tibet

Carboniferous-Triassic magmatism in northern Qiangtang, central Tibet, China, played a key role in the evolution of the Tibetan Plateau yet remains a subject of intense debate. New geochronological and geochemical data from adakitic, Nb-enriched, and normal arc magmatic rocks, integrated with results from previous studies, enable us to determine the Carboniferous-Triassic (312−205 Ma), arc-related, plutonic-volcanic rocks in northern Qiangtang. Spatial-temporal relationships reveal three periods of younging including southward (312−252 Ma), rapid northward (249−237 Ma), and normal northward (234−205 Ma) migrations that correspond to distinct slab geodynamic processes including continentward slab shallowing, rapid trenchward slab rollback, and normal trenchward rollback of the Jinsha Paleotethys rather than the Longmuco-Shuanghu Paleotethys, respectively. Moreover, varying degrees of coexistence of adakites/High-Mg andesites (HMAs)/Nb-enriched basalt-andesites (NEBs) and intraplate basalts in the above-mentioned stages is consistent with the magmatic effects of slab window triggered by ridge subduction, which probably started since the Late Carboniferous and continued into the Late Triassic. The Carboniferous-Triassic multiple magmatic migrations and ridge-subduction scenarios provide new insight into the geodynamic processes of the Jinsha Paleotethys and the growth mechanism of the Tibetan Plateau.

Passive-margin magmatism caused by enhanced slab-pull forces in central Tibet

Geology ◽  
2020 ◽  
Author(s):  
Wei Dan ◽  
Qiang Wang ◽  
William M. White ◽  
Xian-Hua Li ◽  
Xiu-Zheng Zhang ◽  
...  
Keyword(s):  
Passive Margin ◽  
Lower Plate ◽  
Isotopic Signatures ◽  
Ridge Subduction ◽  
Slab Rollback ◽  
Element Enrichment ◽  
Central Tibet ◽  
Back Arc ◽  
Ocean Ridge ◽  
Qiangtang Terrane

We report on a ca. 239 Ma mafic dike swarm intruded in the Southern Qiangtang terrane, central Tibet, that was generated on the passive continental margin of a subducting lower plate. The dikes are tholeiitic basalts and exhibit light rare earth element enrichment, modest negative anomalies in Nb and Ta, and enriched isotopic signatures. The dikes are coeval with a back-arc basin formed in the upper plate as a result of the rollback of the Paleo-Tethys oceanic slab. Thus, after ocean-ridge subduction, enhanced slab-pull forces related to slab rollback on one side of the ocean induced extension and magmatism in the passive margin on the opposite side. We argue that enhanced slab-pull forces are a previously unrecognized mechanism for the generation of lower-plate passive-margin magmatism.

Cambrian magmatic flare-up, central Tibet: Magma mixing in proto-Tethyan arc along north Gondwanan margin

2021 ◽  
Author(s):  
Pei-yuan Hu ◽  
Qing-guo Zhai ◽  
Peter A. Cawood ◽  
Guo-chun Zhao ◽  
Jun Wang ◽  
...  
Keyword(s):  
Magma Mixing ◽  
Geochemical Data ◽  
Early Paleozoic ◽  
East African ◽  
Lhasa Terrane ◽  
The North ◽  
Magmatic Rocks ◽  
East African Orogen ◽  
Andean Type ◽  
Central Tibet

Accompanying Gondwana assembly, widespread but diachronous Ediacaran−early Paleozoic magmatism of uncertain origin occurred along the supercontinent’s proto-Tethyan margin. We report new geochemical, isotopic, and geochronological data for Cambrian magmatic rocks (ca. 500 Ma) from the Gondwana-derived North Lhasa terrane, located in the present-day central Tibetan Plateau. The magmatic rocks are composed of basalts, gabbros, quartz monzonites, granitoids (with mafic microgranular enclaves), and rhyolites. Nd-Hf isotopic and whole-rock geochemical data indicate that these rocks were probably generated by mixing of mantle-derived mafic and crust-derived felsic melts. The mantle end-member volumes of mafic, intermediate, and felsic rocks are ∼75%−100%, 50%−60%, and 0−30%, respectively. Integration of our new data with previous studies suggests that the North Lhasa terrane experienced long-term magmatism through the Ediacaran to Ordovician (ca. 572−483 Ma), with a magmatic flare-up at ca. 500 Ma. This magmatism, in combination with other Ediacaran−early Paleozoic magmatism along the proto-Tethyan margin, was related to an Andean-type arc, with the magmatic flare-up event related to detachment of the oceanic slab following collisional accretion of Asian microcontinental fragments to northern Gondwana. Diachroneity of the proto-Tethyan arc system along the northern Gondwanan margin (ca. 581−531 Ma along the Arabian margin and ca. 512−429 Ma along the Indian-Australian margin) may have been linked to orogenesis within Gondwana. The North Lhasa terrane was probably involved in both Arabian and Indian-Australian proto-Tethyan Andean-type orogens, based on its paleogeographic location at the northern end of the East African orogen.

scholarly journals India-Asia collision as a driver of atmospheric CO2 in the Cenozoic

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhengfu Guo ◽  
Marjorie Wilson ◽  
Donald B. Dingwell ◽  
Jiaqi Liu
Keyword(s):  
Continental Collision ◽  
Causal Link ◽  
Geochemical Data ◽  
Driving Mechanism ◽  
Emission Rates ◽  
Emission Flux ◽  
Magmatic Rocks ◽  
Deep Earth ◽  
Primary Driver ◽  
Three Stages

AbstractDeep Earth degassing is a critical forcing factor for atmospheric CO2 variations and palaeoclimate changes in Earth’s history. For the Cenozoic, the key driving mechanism of atmospheric CO2 variations remains controversial. Here we analyse three stages of collision-related magmatism in Tibet, which correspond temporally with the three major stages of atmospheric CO2 variations in the Cenozoic and explore the possibility of a causal link between these phenomena. To this end we present geochemical data for the three stages of magmatic rocks in Tibet, which we use to inform a model calculating the continental collision-induced CO2 emission flux associated with the evolving Neo-Tethyan to continental subduction over the Cenozoic. The correlation between our modelled CO2 emission rates and the global atmospheric CO2 curve is consistent with the hypothesis that the India-Asia collision was the primary driver of changes in atmospheric CO2 over the Cenozoic.

Early Cretaceous Ridge Subduction along the Southern Margin of the Qiangtang Terrane: New Evidence from the Yanqiang Ling Fragmented Ophiolite, Central Tibet

2018 ◽  
Vol 126 (6) ◽  
pp. 639-654
Author(s):  
Wei Xu ◽  
Ming Wang ◽  
Cai Li ◽  
Jian-Jun Fan ◽  
Jing-Wen Chen ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Ridge Subduction ◽  
Southern Margin ◽  
Central Tibet ◽  
New Evidence ◽  
Qiangtang Terrane

Sources of the magmatic rocks of the Mendeleev Rise, Arctic Ocean: Evidence from isotope-geochemical data

2015 ◽  
Vol 53 (6) ◽  
pp. 487-500 ◽  
Author(s):  
A. A. Kremenetskii ◽  
Yu. A. Kostitsyn ◽  
A. F. Morozov ◽  
P. V. Rekant
Keyword(s):  
Arctic Ocean ◽  
Geochemical Data ◽  
Magmatic Rocks

Co-seismic surface ruptures in Qiangtang Terrane: Insight into Late Cenozoic deformation of central Tibet

2019 ◽  
Vol 750 ◽  
pp. 359-378 ◽  
Author(s):  
Shuai Han ◽  
Haibing Li ◽  
Jiawei Pan ◽  
Haijian Lu ◽  
Yong Zheng ◽  
...  
Keyword(s):  
Late Cenozoic ◽  
Surface Ruptures ◽  
Central Tibet ◽  
Qiangtang Terrane ◽  
Insight Into

scholarly journals A database of Holocene nearshore marine mollusc shell geochemistry from the Northeast Pacific

2021 ◽  
Author(s):  
Hannah M. Palmer ◽  
Veronica Padilla Vriesman ◽  
Roxanne M. W. Banker ◽  
Jessica R. Bean
Keyword(s):  
Carbon Isotope ◽  
Heat Waves ◽  
Indigenous Communities ◽  
Geochemical Data ◽  
Shell Middens ◽  
Data Set ◽  
Oxygen And Carbon Isotope ◽  
Northeast Pacific ◽  
Isotope Data ◽  
Δ13c And Δ18o

Abstract. The shells of marine invertebrates can serve as high-resolution records of oceanographic and atmospheric change through time. In particular, oxygen and carbon isotope analyses of nearshore marine calcifiers that grow by accretion over their lifespans provide seasonal records of environmental and oceanographic conditions. Archaeological shell middens generated by Indigenous communities along the Northeast Pacific coast contain shells harvested over multiple seasons for millennia. These shell middens, as well as analyses of archival and modern shells, have the potential to provide multi-site, seasonal archives of nearshore conditions throughout the Holocene. A significant volume of oxygen and carbon isotope data from archaeological shells exists, yet is separately published in archaeological, geochemical, and paleoceanographic journals and has not been comprehensively analyzed to examine oceanographic change over time. Here, we compiled a database of previously published oxygen and carbon isotope data from archaeological, archival, and modern marine molluscs from the North American coast of the Northeast Pacific (32° N to 50° N). This database includes oxygen and carbon isotope data from over 550 modern, archaeological, and sub-fossil shells from 8880 years before present (BP) to the present, from which there are 4,845 total δ13C and 5,071 total δ18O measurements. Shell dating and sampling strategies vary among studies (1–118 samples per shell) and vary significantly by journal discipline. Data are from various bivalves and gastropod species, with Mytilus spp. being the most commonly analyzed taxon. This novel database can be used to investigate changes in nearshore sea surface conditions including warm-cool oscillations, heat waves, and upwelling intensity, and provides nearshore calcite δ13C and δ18O values that can be compared to the vast collections of offshore foraminifera calcite δ13C and δ18O data from marine sediment cores. By utilizing previously published geochemical data from midden and museum shells rather than sampling new specimens, future scientific research can reduce or omit the alteration or destruction of culturally valued specimens and sites. The data set is publicly available through PANGAEA at https://doi.org/10.1594/PANGAEA.932671 (Palmer et al., 2021).

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