scholarly journals Supplemental Material: Syn-exhumation magmatism in an active continental margin above a continental subduction zone: Evidence from Late Triassic mafic igneous rocks in the southeastern North China Block

Author(s):  
Wei Fang ◽  
Li-Qun Dai

Table S1: Major and trace element compositions of mafic igneous rocks from the southeastern North China Block; Table S2: Whole-rock Rb-Sr, Sm-Nd, and Lu-Hf isotope compositions of mafic igneous rocks from the southeastern North China Block; Table S3: LA-ICPMS zircon U-Pb isotope compositions of mafic igneous rocks from the southeastern North China Block; Table S4: Zircon LA-MC-ICPMS Lu-Hf and SIMS O isotopic compositions of mafic igneous rocks from the southeastern North China Block.

2020 ◽  
Author(s):  
Wei Fang ◽  
Li-Qun Dai

Table S1: Major and trace element compositions of mafic igneous rocks from the southeastern North China Block; Table S2: Whole-rock Rb-Sr, Sm-Nd, and Lu-Hf isotope compositions of mafic igneous rocks from the southeastern North China Block; Table S3: LA-ICPMS zircon U-Pb isotope compositions of mafic igneous rocks from the southeastern North China Block; Table S4: Zircon LA-MC-ICPMS Lu-Hf and SIMS O isotopic compositions of mafic igneous rocks from the southeastern North China Block.


Author(s):  
Wei Fang ◽  
Li-Qun Dai ◽  
Yong-Fei Zheng ◽  
Zi-Fu Zhao ◽  
Qi Chen ◽  
...  

Syn-subduction arc magmatism is absent above continental subduction zones, providing important constraints on the nature of petrogenetic processes during continental collision. Nevertheless, we have identified syn-exhumation mafic igneous rocks in an active continental margin above a continental subduction zone, where the South China Block (SCB) was deeply subducted beneath the North China Block (NCB) for collisional orogeny in the Triassic. These mafic igneous rocks occur in the southeastern margin of the NCB, showing consistent Late Triassic zircon U-Pb ages of ca. 219−218 Ma, coeval with exhumation of the deeply subducted continental crust. These rocks are categorized into two series of sub-alkaline and alkaline, all exhibiting arc-like trace element distribution patterns, highly enriched radiogenic Sr-Nd-Hf and high zircon O isotope compositions. In particular, they exhibit two-stage whole-rock Nd and Hf model ages and zircon Hf model ages of Paleoproterozoic, which are comparable to those of ultrahigh-pressure metamorphic rocks with the SCB affinity in the Dabie-Sulu orogenic belt. Such geochemical features indicate that these mafic igneous rocks were derived from partial melting of ultramafic metasomatites generated by reaction of felsic melts from the subducted SCB with the mantle wedge peridotite beneath the NCB. The geochemical differences in element and isotope compositions between the two series igneous rocks can be mainly ascribed to different proportions of the crustal component in the metasomatites, which is verified by quantitative modellings of the geochemical transfer in the continental subduction zone. The systematic variations in some geochemical variables such as Fe/Mn, Zn/Fe, and Nb/Ta ratios indicate pyroxenite-rich and hornblendite-rich lithologies, respectively, for the sub-alkaline and alkaline series igneous rocks. With the tectonic extension for exhumation of the deeply subducted continental crust in the Late Triassic, the fertile and enriched metasomatites in the mantle wedge underwent partial melting for the syn-exhumation mafic magmatism in the southeastern NCB. Therefore, the mafic igneous rocks in the active continental margin not only record the crust-mantle interaction in the continental subduction zone, but also witness the generation of syn-exhumation magmatism in the late stage of continental collision.


2020 ◽  
Author(s):  
Peng Wang ◽  
Guochun Zhao ◽  
et al.

Table S1: Zircon U-Pb ages of igneous rocks in the Western Kunlun orogenic belt; Table S2: Results of whole-rock major- (wt%) and trace-element (ppm) data from the three intrusions; Table S3: Zircon U-Pb age of the three intrusions; Table S4: Zircon Hf isotope compositions of the three intrusions; Table S5: Whole-rock Sr-Nd-Pb isotope compositions of the three intrusions; Table S6: Representative analyses of feldspar, amphibole, and pyroxene from the Aqiang and Yutian intrusions; Table S7: Bulk partition coefficients used for trace-element modeling in Figure 14; Figure S1: CL images of zircons showing internal textures and ages of 206Pb/238U (Ma).


2012 ◽  
Vol 524-527 ◽  
pp. 16-23
Author(s):  
Jian Guo Huang ◽  
Run Sheng Han ◽  
Ren Tao ◽  
Zhi Qiang Li

The Late Triassic Tumugou Formation volcanic rocks which belongs to typical island arc volcanic rocks in southern end of Yidun island arc belt is located at the eastern of the Zhongdian ,NW Yunnan, SW China. The volcanic rocks can be divided into three categories:andesitic basalt, andesite, quartz andesite, etc. Through geochemical analysis the major elements, rare earth ele and trace element in volcanic rocks, SiO255.18-57.59×10-2,TiO21.16-1.45×10-2,Na2O+K2O5.11-8.05×10-2.consider it is calc-alkaline- alkaline Series of high-K andesite, volcanic may be controlled by the crystal fractionation of magma.Rb31.50-101×10-6,Ba1310-12300×10-6,Nb/Ta11.4-15.5,REE166.07-240.78×10-6,δEu0.74-1.00,REE distribution patterns show oblique to the HREE side and enrichment in LREE .Eu anomaly is not obvious. It is can see from the relevant figure about trace element, it is very similar in magmatic distribution patterns between volcanic rock and Volcanic-arc rock, indicating that the volcanic in this area may be formed in volcanic-arc environment. From east to west, Magma source depth have regular change with the really thickness of mainland shell. Explain that Tumugou Formation volcanic rock is subduction by Ganzi- Litang Ocean basin from east to west. Hongshan-Ousaila region of eastern edge of Zhongdian is the volcanic island arc system during the passive continental margin into an active continental margin.


2007 ◽  
Vol 164 (2) ◽  
pp. 451-463 ◽  
Author(s):  
SHUAN-HONG ZHANG ◽  
YUE ZHAO ◽  
BIAO SONG ◽  
ZHEN-YU YANG ◽  
JIAN-MIN HU ◽  
...  

2020 ◽  
Author(s):  
Peng Wang ◽  
Guochun Zhao ◽  
et al.

Table S1: Zircon U-Pb ages of igneous rocks in the Western Kunlun orogenic belt; Table S2: Results of whole-rock major- (wt%) and trace-element (ppm) data from the three intrusions; Table S3: Zircon U-Pb age of the three intrusions; Table S4: Zircon Hf isotope compositions of the three intrusions; Table S5: Whole-rock Sr-Nd-Pb isotope compositions of the three intrusions; Table S6: Representative analyses of feldspar, amphibole, and pyroxene from the Aqiang and Yutian intrusions; Table S7: Bulk partition coefficients used for trace-element modeling in Figure 14; Figure S1: CL images of zircons showing internal textures and ages of 206Pb/238U (Ma).


2020 ◽  
Author(s):  
Wei Fang ◽  
Li-Qun Dai ◽  
et al.

Table S1: Major and trace element compositions of lamprophyres from the eastern North China Craton; Table S2: Whole-rock Sr, Nd, and Hf isotope compositions of lamprophyres from the eastern North China Craton; Table S3: LA-ICPMS Zircon U-Pb isotope compositions of lamprophyres from the eastern North China Craton; Table S4: Zircon LA-MC-ICPMS Lu-Hf isotope compositions of lamprophyres from the eastern North China Craton.


2020 ◽  
Author(s):  
Wei Fang ◽  
Li-Qun Dai ◽  
et al.

Table S1: Major and trace element compositions of lamprophyres from the eastern North China Craton; Table S2: Whole-rock Sr, Nd, and Hf isotope compositions of lamprophyres from the eastern North China Craton; Table S3: LA-ICPMS Zircon U-Pb isotope compositions of lamprophyres from the eastern North China Craton; Table S4: Zircon LA-MC-ICPMS Lu-Hf isotope compositions of lamprophyres from the eastern North China Craton.


2019 ◽  
Vol 157 (4) ◽  
pp. 677-689 ◽  
Author(s):  
Binsong Zheng ◽  
Chuanlong Mou ◽  
Renjie Zhou ◽  
Xiuping Wang ◽  
Zhaohui Xiao ◽  
...  

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.


2019 ◽  
Vol 64 (5) ◽  
pp. 503-519
Author(s):  
R. O. Ovchinnikov ◽  
A. A. Sorokin ◽  
V. P. Kovach ◽  
A. B. Kotov

The first data about geochemical features of the Cambrian sedimentary rocks of the Mel’gin trough of the Bureya continental Massif, as well as ages of detrital zircons of them are obtained. It is established, that among the detrital zircons from the sandstones of the Chergilen and Allin formations of the Mel’gin trough zircons with Late Riphean (peaks on relative probability plots – 0.78, 0.82, 0.94, 1.04 Ga) and Early Riphean (peaks on relative probability plots – 1.38, 1.45, 1.64 Ga) ages predominate. The single grains have a Middle Riphean, Early Proterozoic and Late Archean ages. We can suppose, that the sources of Late Riphean detrital zircons from sandstones of the Chergilen and Allin formations are igneous rocks of gabbro-granitoids (940–933 Ma) and granite- leucogranites (804–789 Ma) association, identified in the Bureya continental Massif. We can`t assume, what kind of rocks were the source for Middle Riphean and older detrital zircons from the Cambrian sedimentary rocks of the Bureya continental Massif, because in this massif still do not identified complexes older Late Riphean age. The most probable geodynamic conditions of accumulation of the Cambrian deposits of the Mel’gin trough is the conditions of active continental margin, which is corresponding to of Early Cambrian granitoids magmatism.


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