气候变化领域集成服务门户(CCPortal): Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos

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DOI	10.1130/B35605.1
	Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos
	Wang Y.; Zhang Y.; Qian X.; Senebouttalath V.; Wang Y.; Wang Y.; Gan C.; Zaw K.
发表日期	2020
ISSN	167606
起始页码	325
结束页码	346
卷号	133
英文摘要	In order to verify the early Paleozoic accretionary assemblage in the Indochina interior and constrain the Prototethyan tectonic evolution in Southeast Asia, this study presents a set of new U-Pb geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic data for the fiftytwo representative granitoids in South Laos. The granitoids from the Kontum terrane, Tam Ky-Phuoc Son tectonic zone, and southern Truong Son igneous zone in South Laos yield the crystallization ages of 464–485 Ma, 455– 471 Ma, and 427–446 Ma, respectively, with a northerly younging trend within the Indochina interior. They are mainly monzogranite with A/CNK = 0.96–1.99 and K2O > Na2O, which are marked by enrichment in largeion lithophile elements and depletion in high field strength elements with remarkable Nb- Ta, Sr-P, and Ti negative anomalies. Their initial 87Sr/86Sr ratios range from 0.70510 to 0.71559, εNd(t) from −9.5 to −3.0, (206Pb/204Pb)i from 18.65 to 19.72, (207Pb/204Pb)i from 15.66 to 15.80, and (208Pb/ 204Pb)i from 38.84 to 39.79. The corresponding zircon ɛHf(t) and δ18O values are in the range of −10.6 to +1.0 and 6.88‰ to 8.94‰, respectively. In addition, their Sr-Nd-Pb and Hf-O isotopic compositions are generally similar with those of time-equivalent granitoids in South Tibet and SW Yunnan, China, and synchronous maficintermediate igneous rocks in South Laos, but distinctive from those of the supracrustal sedimentary-derived South China Paleozoic granite and Lincang-Sukhothai S-type granite. The early Paleozoic granitoids in South Laos might have originated from a mixed source of the wedge-derived juvenile crust coupled with supracrustal materials. All these data synthetically suggest the southward subduction of the Tam Ky-Phuoc Son Ocean and the northerly on-growing Ordo-Silurian accretionary orogenesis within the previously defined “single-ancient” Indochina block. The assemblage of the Indochina block might initiate at ca. 430 Ma in the Silurian and terminate in the Early-Middle Devonian. © 2020 Geological Society of America
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184768
作者单位	Guangdong Provincial Key Lab of Geodynamics and Geohazards, School of Earth Sciences and Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, 519082, China; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; CODES Centre of Ore Deposits and Earth Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
推荐引用方式 GB/T 7714	Wang Y.,Zhang Y.,Qian X.,et al. Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos[J],2020,133.
APA	Wang Y..,Zhang Y..,Qian X..,Senebouttalath V..,Wang Y..,...&Zaw K..(2020).Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos.Bulletin of the Geological Society of America,133.
MLA	Wang Y.,et al."Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos".Bulletin of the Geological Society of America 133(2020).