Magmatic record of the Mesozoic geology of Hainan Island and its implications for the Mesozoic tectonomagmatic evolution of SE China: effects of slab geometry and dynamics in continental tectonics

2020 ◽  
Vol 158 (1) ◽  
pp. 118-142 ◽  
Author(s):  
Yildirim Dilek ◽  
Limei Tang
Keyword(s):  
Hainan Island ◽  
Pacific Plate ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Slab Geometry ◽  
Extensional Deformation ◽  
Metamorphic Core Complexes ◽  
Range Type ◽  
Flat Slab Subduction ◽  
Se China

AbstractOur field-based geochemical studies of the Triassic, Jurassic and Cretaceous granitoids on Hainan Island indicate that their magmas had different geochemical affinities, changing from alkaline in the Triassic through ocean island basalt (OIB) in the Jurassic, to calc-alkaline in the Cretaceous. We show that these changes in the geochemical affinities of the Mesozoic granitoids on Hainan and in SE China reflect different melt sources and melt evolution patterns through time. Our new geodynamic model suggests that: (1) Triassic geology was controlled by flat-slab subduction of the palaeo-Pacific plate beneath SE China. This slab dynamics resulted in strong coupling between the lower and upper plates, causing push-over tectonics and contractional deformation in SE China. Flat subduction-induced edge flow and aesthenospheric uprising led to the production of high-K granites, syenites and mafic rocks. (2) Slab foundering, accelerated subduction rates and subduction hinge retreat in the Early Jurassic caused rapid rollback of the downgoing slab. Strong decoupling of the upper and lower plates resulted in pull-away tectonics, producing extensional deformation in SE China. Decompression melting of the upwelling aesthenosphere produced OIB-type melts, which interacted with the subcontinental lithospheric mantle (SCLM) to form A- and I-type granitoids. (3) Segmentation of the palaeo-Pacific plate in the Early Cretaceous resulted in steeply dipping slabs and their faster rollback, facilitating lithospheric-scale extension and oceanward migration of calc-alkaline magmatism. This extensional deformation played a significant role in the formation of metamorphic core complexes, widespread crustal melting and development of a Basin and Range-type tectonics and landscape evolution in SE China.

Early Jurassic calc-alkaline magmatism in northeast China: Magmatic response to subduction of the Paleo-Pacific Plate beneath the Eurasian continent

2017 ◽  
Vol 143 ◽  
pp. 249-268 ◽  
Author(s):  
Feng Wang ◽  
Yi-Gang Xu ◽  
Wen-Liang Xu ◽  
Lei Yang ◽  
Wei Wu ◽  
...  
Keyword(s):  
Northeast China ◽  
Pacific Plate ◽  
Early Jurassic ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Eurasian Continent

Cretaceous crustal melting records of tectonic transition from subduction to slab rollback of the Paleo-Pacific Plate in SE China

Lithos ◽  
2021 ◽  
Vol 384-385 ◽  
pp. 105985
Author(s):  
Liang Zhao ◽  
Feng Guo ◽  
Xiaobing Zhang ◽  
Guoqing Wang
Keyword(s):  
Pacific Plate ◽  
Crustal Melting ◽  
Tectonic Transition ◽  
Slab Rollback ◽  
Se China

scholarly journals 207Pb-206Pb dating of magnetite, monazite and allanite in the central and northern Nagssugtoqidian orogen, West Greenland

2006 ◽  
Vol 11 ◽  
pp. 101-114 ◽  
Author(s):  
Henrik Stendal ◽  
Karsten Secher ◽  
Robert Frei
Keyword(s):  
Hydrothermal Activity ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Isotopic Data ◽  
Sulphide Deposit ◽  
Late Archaean ◽  
West Greenland ◽  
Isotopic Signatures ◽  
Source Characteristics ◽  
Isotopic Measurements

Pb-isotopic data for magnetite from amphibolites in the Nagssugtoqidian orogen, central West Greenland, have been used to trace their source characteristics and the timing of metamorphism. Analyses of the magnetite define a Pb-Pb isochron age of 1726 ± 7 Ma. The magnetite is metamorphic in origin, and the 1726 Ma age is interpreted as a cooling age through the closing temperature of magnetite at ~600°C. Some of the amphibolites in this study come from the Naternaq supracrustal rocks in the northern Nagssugtoqidian orogen, which host the Naternaq sulphide deposit and may be part of the Nordre Strømfjord supracrustal suite, which was deposited at around 1950 Ma ago. Pb-isotopic signatures of magnetite from the Arfersiorfik quartz diorite in the central Nagssugtoqidian orogen are compatible with published whole-rock Pb-isotopic data from this suite; previous work has shown that it is a product of subduction-related calc-alkaline magmatism between 1920 and 1870 Ma. Intrusion of pegmatites occurred at around 1800 Ma in both the central and the northern parts of the orogen. Pegmatite ages have been determined by Pb stepwise leaching analyses of allanite and monazite, and source characteristics of Pb point to an origin of the pegmatites by melting of the surrounding late Archaean and Palaeoproterozoic country rocks. Hydrothermal activity took place after pegmatite emplacement and continued below the closure temperature of magnetite at 1800– 1650 Ma. Because of the relatively inert and refractory nature of magnetite, Pb-isotopic measurements from this mineral may be of help to understand the metamorphic evolution of geologically complex terrains.

The relationship between potassic, calc-alkaline and Na-alkaline magmatism in South Italy volcanoes: A melt inclusion approach

2004 ◽  
Vol 220 (1-2) ◽  
pp. 121-137 ◽  
Author(s):  
Pierre Schiano ◽  
Robert Clocchiatti ◽  
Luisa Ottolini ◽  
Alessandro Sbrana
Keyword(s):  
Melt Inclusion ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
South Italy ◽  
The Relationship

Fluids composition in the mantle beneath the Eastern Transylvanian Basin inferred from mineral chemistry and noble gases in fluid inclusions of ultramafic xenoliths

2021 ◽  
Author(s):  
Andrea Luca Rizzo ◽  
Barbara Faccini ◽  
Costanza Bonadiman ◽  
Theodoros Ntaflos ◽  
Ioan Seghedi ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Noble Gases ◽  
Mineral Chemistry ◽  
Mantle Xenoliths ◽  
Alkaline Magmatism ◽  
Volcanic Area ◽  
Crustal Material ◽  
Calc Alkaline ◽  
Depleted Mantle ◽  
Magmatic Gases

<p>The investigation of noble gases (He, Ne, Ar) and CO<sub>2</sub> in fluid inclusions (FI) of mantle-derived rocks from the Sub Continental Lithospheric Mantle (SCLM) is crucial for constraining its geochemical features and evolution as well as the volatiles cycle, and for better evaluating the information arising from the study and monitoring of volcanic and geothermal gases. Eastern Transylvanian Basin in Romania is one of the places in Central-Eastern Europe where mantle xenoliths are brought to the surface by alkaline magmatism, offering the opportunity for applying the above-mentioned approach. Moreover, this locality is one of the few places on Earth where alkaline eruptions occurred contemporaneously with calc-alkaline activity, thus being a promising area for the investigation of subduction influence on the magma sources and volatiles composition.</p><p>In this work, we studied petrography, mineral chemistry and noble gases in FI of mantle xenoliths found in Perşani Mts. alkaline volcanic products. Our findings reveal that the local mantle recorded two main events. The first was a pervasive, complete re-fertilization of a previously depleted mantle by a calc-alkaline subduction-related melt, causing the formation of very fertile, amphibole-bearing lithotypes. Fluids involved in this process and trapped in olivine, opx and cpx, show <sup>4</sup>He/<sup>40</sup>Ar* ratios up to 1.2 and among the most radiogenic <sup>3</sup>He/<sup>4</sup>He values of the European mantle (5.8 ± 0.2 Ra), reflecting the recycling of crustal material in the local lithosphere. The second event is related to a later interaction with an alkaline metasomatic agent similar to the host basalts, that caused slight LREE enrichment in pyroxenes and crystallization of disseminated amphiboles, with FI showing <sup>4</sup>He/<sup>40</sup>Ar* and <sup>3</sup>He/<sup>4</sup>He values up to 2.5 and 6.6 Ra, respectively, more typical of magmatic fluids.</p><p>Although volcanic activity in the Perşani Mts. is now extinct, strong CO<sub>2</sub> degassing (8.7 × 10<sup>3</sup> t/y) in the neighbouring Ciomadul volcanic area may indicate that magma is still present at depth (Kis et al., 2017; Laumonier et al., 2019). The gas manifestations present from Ciomadul area are the closest to the outcrops containing mantle xenoliths for comparison of the noble gas composition in FI. <sup>3</sup>He/<sup>4</sup>He values from Stinky Cave (Puturosul), Doboşeni and Balvanyos are up to 3.2, 4.4 and 4.5 Ra, respectively, indicating the presence of a cooling magma (Vaselli et al., 2002 and references therein). In the same area and more recently, Kis et al. (2019) measured <sup>3</sup>He/<sup>4</sup>He ratios up to 3.1 Ra, arguing that these values indicate a mantle lithosphere strongly contaminated by subduction-related fluids and post-metasomatic ingrowth of radiogenic <sup>4</sup>He. Our findings consider more likely that magmatic gases from Ciomadul volcano are not representative of the local mantle but are being released from a cooling and aging magma that resides within the crust. Alternatively, crustal fluids contaminate magmatic gases while they are rising to the surface.</p><p> </p><p>Kis et al. (2017). Journal of Volcanology and Geothermal Research 341, 119–130.</p><p>Kis et al. (2019) Geochem. Geophys. Geosyst. 20, 3019-3043.</p><p>Laumonier et al. (2019) Earth and Planetary Science Letters, 521, 79-90.</p><p>Vaselli et al. (2002) Chemical Geology 182, 637–654.</p>

scholarly journals A step towards unraveling the paleogeographic attribution of pre-Mesozoic basement complexes in the Western Alps based on U–Pb geochronology of Permian magmatism

2020 ◽  
Vol 113 (1) ◽  
Author(s):  
Michel Ballèvre ◽  
Audrey Camonin ◽  
Paola Manzotti ◽  
Marc Poujol
Keyword(s):  
Early Stage ◽  
Western Alps ◽  
Geochemical Data ◽  
Alkaline Magmatism ◽  
Low Grade ◽  
Calc Alkaline ◽  
Alpine Orogeny ◽  
History Of ◽  
External Part ◽  
The One

Abstract The Briançonnais Domain (Western Alps) represented the thinned continental margin facing the Piemonte-Liguria Ocean, later shortened during the Alpine orogeny. In the external part of the External Briançonnais Domain (Zone Houillère), the Palaeozoic basement displays microdioritic intrusions into Carboniferous sediments and andesitic volcanics resting on top of the Carboniferous sediments. These magmatic rocks are analysed at two well-known localities (Guil volcanics and Combarine sill). Geochemical data show that the two occurrences belong to the same calc-alkaline association. LA-ICP-MS U–Pb ages have been obtained for the Guil volcanics (zircon: 291.3 ± 2.0 Ma and apatite: 287.5 ± 2.6 Ma), and the Combarine sill (zircon: 295.9 ± 2.6 Ma and apatite: 288.0 ± 4.5 Ma). These ages show that the calc-alkaline magmatism is of Early Permian age. During Alpine orogeny, a low-grade metamorphism, best recorded by lawsonite-bearing veins in the Guil andesites, took place at about 0.4 GPa, 350 °C in the External Briançonnais and Alpine metamorphism was not able to reset the U–Pb system in apatite. The Late Palaeozoic history of the Zone Houillère is identical to the one recorded in the Pinerolo Unit, located further East in the Dora-Maira Massif, and having experienced a garnet-blueschist metamorphism during the Alpine orogeny. The comparison of these two units allows for a better understanding of the link between the Palaeozoic basements, mostly subducted during the Alpine convergence, and their Mesozoic covers, generally detached at an early stage of the convergence history.

Geodynamic Evolution of Flat‐Slab Subduction of Paleo‐Pacific Plate: Constraints From Jurassic Adakitic Lavas in the Hailar Basin, NE China

Tectonics ◽  
2019 ◽  
Vol 38 (12) ◽  
pp. 4301-4319 ◽  
Author(s):  
Zheng Ji ◽  
Qi‐An Meng ◽  
Chuan‐Biao Wan ◽  
De‐Feng Zhu ◽  
Wen‐Chun Ge ◽  
...  
Keyword(s):  
Pacific Plate ◽  
Ne China ◽  
Geodynamic Evolution ◽  
Flat Slab ◽  
Hailar Basin ◽  
Flat Slab Subduction

Tertiary calc-alkaline magmatism associated with lithospheric extension in the Pacific Northwest

1995 ◽  
Vol 100 (B6) ◽  
pp. 10303-10319 ◽  
Author(s):  
P. R. Hooper ◽  
D. G. Bailey ◽  
G. A. McCarley Holder
Keyword(s):  
Pacific Northwest ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
The Pacific ◽  
Lithospheric Extension
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