Zircon U‐Pb Chronology and Hf Isotope From the Palawan‐Mindoro Block, Philippines: Implication to Provenance and Tectonic Evolution of the South China Sea
Zircon U‐Pb Chronology and Hf Isotope From the Palawan‐Mindoro Block, Philippines: Implication to Provenance and Tectonic Evolution of the South China Sea
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DOI：
10.1002/2017tc004942
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发表时间：
2018-04
期刊：
影响因子：
4.2
通讯作者：
Yi Yan;D. Yao;Zhi-xian Tian;Chi‐Yue Huang;Wenhuang Chen;M. Santosh;G. Yumul;C. Dimalanta;Zian Li
中科院分区：
文献类型：
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作者：
Yi Yan;D. Yao;Zhi-xian Tian;Chi‐Yue Huang;Wenhuang Chen;M. Santosh;G. Yumul;C. Dimalanta;Zian Li
东南亚大陆边缘由中生代的安第斯型活动边缘演化为晚白垩世以来的西太平洋型活动边缘。随着南海的扩张，巴拉望-民都洛地块从亚洲大陆漂移出来，新生代地层为了解东南亚边缘构造演化提供了一个很好的窗口。通过对菲律宾巴拉望-民都洛地块新生代沉积岩中碎屑锆石的U-Pb年龄和Hf同位素数据的分析，探讨南海的物源和构造演化。巴拉望-民都洛地块始新世-中新世沉积岩中的锆石颗粒显示出60 - 2700 Ma的广泛年龄范围，有四个主要年龄组：80 - 120 Ma，160 - 180 Ma，1600 - 2100 Ma和2200 - 2700 Ma。民都洛岛锆石的ε Hf（t）介于− 39~+13.7之间，古近纪和新近纪地层中的Hf同位素组成相似。巴拉望-民都洛地块始新世样品的锆石U-Pb年龄和Hf同位素数据显示与台湾相似的模式，这表明巴拉望-民都洛地块在晚白垩世-始新世时期附着于华南边缘。巴拉望-民都洛地块与台湾中新世样品中锆石U-Pb年龄组成的差异反映了当时巴拉望-民都洛地块向南漂移和南海海底扩张。
The continental margin of Southeast Asia evolved from a dominantly Andean‐type active margin during Mesozoic to a Western Pacific‐type since Late Cretaceous. With the spreading of the South China Sea, the Palawan‐Mindoro Block drifted from mainland Asia and the Cenozoic strata provide an excellent window to gain insights into the tectonic evolution of the margin of Southeast Asia. Here we present U‐Pb age and Hf isotopic data on detrital zircon grains from Cenozoic sedimentary rocks in the Palawan‐Mindoro Block, Philippines, to evaluate the provenance and tectonic evolution of the South China Sea. Zircon grains in Eocene‐Miocene sedimentary rocks from the Palawan‐Mindoro Block show a wide range in age from 60 to 2700 Ma, with four major age groups of 80–120 Ma, 160–180 Ma, 1600–2100 Ma, and 2200–2700 Ma. The εHf(t) of the zircon grains of the samples from Mindoro Island range from −39 to +13.7, and similar Hf isotopic composition is recorded in Paleogene and Neogene strata. Zircon U‐Pb ages and Hf isotopic data of the Eocene samples from the Palawan‐Mindoro Block show a similar pattern with those from Taiwan, which suggests that the Palawan‐Mindoro Block was attached to the margin of South China during Late Cretaceous‐Eocene times. The difference of zircon U‐Pb age composition in the Miocene samples between the Palawan‐Mindoro Block and Taiwan reflects southward drifting of the Palawan‐Mindoro Block and seafloor spreading of the South China Sea at that time.