Cretaceous forearc basin remnant sediments in the eastern Yarlung Zangbo suture zone, near the eastern Himalaya syntaxis
Cretaceous forearc basin remnant sediments in the eastern Yarlung Zangbo suture zone, near the eastern Himalaya syntaxis
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雅鲁藏布江缝合带东部喜马拉雅构造结附近的白垩纪弧前盆地残余沉积物
DOI：
10.1016/j.palaeo.2021.110620
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发表时间：
2021-08
影响因子：
3
通讯作者：
Fan Xiaolong
中科院分区：
文献类型：
--
作者：
Wei Zhen;Li Xianghui;Laskowski Andrew K.;Reynolds Aislin N.;Fan Xiaolong
越岛喜马拉雅（Gangdese）弧前盆地体系东段白垩纪低品位变质沉积记录尚未见报道，影响了对亚洲南缘中新生代辐合边缘过程的认识。本研究结合岩石学、地层学、沉积学、碎屑锆石年代学和块岩Sr-Nd同位素分析，对西藏东南部郎县以东的雅鲁藏布江缝合带东部的一系列低品位变质沉积岩进行了研究。野外观测表明，该单元具有3种不同的岩性组合（I、II、III），分别为砾石-粗砂质内-中海底扇相、砂质-泥质中-外海底扇相、粉砂质-泥质外海底扇相和（或）在演替过程中向上移动的深海平原相。碎屑-锆石年代学表明，盆地最大沉积年龄为~110 Ma，而盆地北部冈底斯岩基中较年轻的锆石的缺失表明，盆地最小沉积年龄为~ 85 Ma，包括一个阿尔滨-三东期的区间。砂岩/砾岩中的火山碎屑和花岗质碎屑、板岩的εNd(0)值（- 0.09和4.6）和87sr /86Sr比值（0.704105 ~ 0.704770）以及碎屑锆石年龄谱（主要为100 ~ 140 Ma）表明物源来自拉萨地体中北部和南部。此外，还发现了冲堆组砂质层的再循环现象。在物源、岩相、构造背景等方面的相似性使我们认为新发现的残余单元与日喀则弧前盆地的阿格玛令组有关。考虑到下波米群和林芝杂岩，我们认为东喜马拉雅造合带的利龙演替和变质复合是东日喀则前弧盆地体系的对应残余，与西喜马拉雅的两个前弧盆地体系不同。
Low-grade metamorphosed Cretaceous sedimentary records of forearc basin systems in the eastern part of the Transhimalaya (Gangdese) arc system have not been reported yet, impairing understanding of the Mesozoic-Cenozoic convergent margin processes along the southern margin of Asia. This study incorporates observations from petrography, stratigraphy, sedimentology, and analyses of detrital-zircon geochronology and bulk-rock Sr-Nd isotope for a series of low-grade metamorphosed sedimentary rocks referred to as the Lilong succession in the eastern Yarlung Zangbo suture zone, east of Langxian, in southeastern Tibet, China. Field observations reveal that this unit has three different lithological associations (I, II, and III) including gravel-coarse sandy inner-middle submarine fan facies, sandy-muddy middle-outer submarine fan facies, and silty-muddy outer submarine fan and/or deep sea plain facies moving higher in the succession. Detrital-zircon geochronology indicates a maximum depositional age of ~110 Ma and the absence of younger zircons that are dominant in the Gangdese batholith north of the basin suggests the minimum depositional age ~ 85 Ma, comprising an interval of the Albian-Santonian age. Volcanic and granitic clasts in sandstones/conglomerates,εNd(0) values (−0.09 and 4.6) and87Sr/86Sr ratios (0.704105–0.704770) of slates, and detrital zircon age spectra (mainly 100–140 Ma) demonstrate provenance from the central-northern and southern Lhasa Terrane. In addition, there is evidence for recycling of cherty beds of the Chongdui Formation. Similarities between provenance, lithofacies, and tectonic setting lead us to interpret that the newly identified remnant unit correlates to the Ngamring Formation in the Xigaze forearc basin. When taking into account the lower Bomi Group and Nyingchi complex, we propose that the Lilong succession and the metamorphosed composite in the eastern Himalayan syntaxis are counterpart remnants of the eastern Xigaze forearc basin system, which are different from the two forearc basin systems in the western Himalaya.
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影响因子：
2.9
作者：
Y. Rolland;A. Pêcher;C. Picard
通讯作者：
Y. Rolland;A. Pêcher;C. Picard
影响因子：
12.1
作者：
G. Shanmugam;R. J. Moiola
通讯作者：
G. Shanmugam;R. J. Moiola
DOI：
10.1130/gsab.s.12670091
发表时间：
2020-07
期刊：
GSA Bulletin
影响因子：
--
作者：
J. Dai;E. al.
通讯作者：
J. Dai;E. al.
影响因子：
3.5
作者：
Chao Wang;L. Ding;Liyun Zhang;P. Kapp;A. Pullen;Yahui Yue
通讯作者：
Chao Wang;L. Ding;Liyun Zhang;P. Kapp;A. Pullen;Yahui Yue
影响因子：
3.2
作者：
D. Orme;A. Laskowski;Misia F. Zilinsky;Wang Chao;Xudong Guo;Fulong Cai;D. Lin
通讯作者：
D. Orme;A. Laskowski;Misia F. Zilinsky;Wang Chao;Xudong Guo;Fulong Cai;D. Lin