{"title":"对 20.5-18 Ma 以来东南亚地球动力学认识的革命","authors":"Jean-Claude Sibuet , Siqing Liu , Minghui Zhao , Wen-Nan Wu , Yih-Min Wu , Jinhui Cheng , Jonny Wu","doi":"10.1016/j.tecto.2024.230397","DOIUrl":null,"url":null,"abstract":"<div><p>We present an updated evaluation of SE Asian geodynamics that includes the interactions of the South China Sea (SCS) marginal basin with surrounding plates since the end of SCS spreading 20.5–18 Ma. Newly available Ar<sup>39</sup>/Ar<sup>40</sup> ages of SCS oceanic crust drilled at IODP U1431 near the SCS East basin extinct spreading center are older than 18 Ma. Conversely, the oldest ages of the Luzon arc and forearc at Taiwan's Lanyu island, Coastal range and Lichi mélange are 17–18 Ma, suggesting that onset of the Manila subduction zone may have begun a few m.y. earlier. Before ∼20.5 Ma, the northern part of the Manila transcurrent fault (MTF), considered as the western boundary of the Ryukyu subduction zone, was a left-lateral lithospheric-scale shear zone. From ∼20.5–18 Ma to ∼7 Ma, this portion of MTF was connected to the Manila trench. Since ∼7 Ma, the MTF extended into the Taiwan Longitudinal valley and continued southwards to north Luzon island as near-vertical, left-lateral shear zone. Today, south of ∼24°N, the MTF protrudes down to 30 km depths and terminates above the deeper Manila slab. Since ∼7 Ma, the whole MTF shifted 400 km westward with respect to Eurasia and rotated ∼23° clockwise to become oriented ∼NS north of 16°N latitude. We identify a tear fault in the Eurasian (EU) plate north of the Ryukyu trench that is located south of the Myako and Yonaguni islands. Since ∼10 Ma, the tear continuously progressed westward within EU crust, with the Philippine Sea plate progressively subducting northwestward between the two lips of the tear fault. A RFF (ridge-fault-fault) triple junction was active in the EU crust before 20.5 Ma, from 10 to 7 Ma, and since 2 Ma. This triple junction was always located on the MTF with one branch of the MTF on each side of the triple junction, and the third branch being the spreading center.</p></div>","PeriodicalId":22257,"journal":{"name":"Tectonophysics","volume":"884 ","pages":"Article 230397"},"PeriodicalIF":2.7000,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A revolution in understanding SE Asia geodynamics since 20.5–18 Ma\",\"authors\":\"Jean-Claude Sibuet , Siqing Liu , Minghui Zhao , Wen-Nan Wu , Yih-Min Wu , Jinhui Cheng , Jonny Wu\",\"doi\":\"10.1016/j.tecto.2024.230397\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We present an updated evaluation of SE Asian geodynamics that includes the interactions of the South China Sea (SCS) marginal basin with surrounding plates since the end of SCS spreading 20.5–18 Ma. Newly available Ar<sup>39</sup>/Ar<sup>40</sup> ages of SCS oceanic crust drilled at IODP U1431 near the SCS East basin extinct spreading center are older than 18 Ma. Conversely, the oldest ages of the Luzon arc and forearc at Taiwan's Lanyu island, Coastal range and Lichi mélange are 17–18 Ma, suggesting that onset of the Manila subduction zone may have begun a few m.y. earlier. Before ∼20.5 Ma, the northern part of the Manila transcurrent fault (MTF), considered as the western boundary of the Ryukyu subduction zone, was a left-lateral lithospheric-scale shear zone. From ∼20.5–18 Ma to ∼7 Ma, this portion of MTF was connected to the Manila trench. Since ∼7 Ma, the MTF extended into the Taiwan Longitudinal valley and continued southwards to north Luzon island as near-vertical, left-lateral shear zone. Today, south of ∼24°N, the MTF protrudes down to 30 km depths and terminates above the deeper Manila slab. Since ∼7 Ma, the whole MTF shifted 400 km westward with respect to Eurasia and rotated ∼23° clockwise to become oriented ∼NS north of 16°N latitude. We identify a tear fault in the Eurasian (EU) plate north of the Ryukyu trench that is located south of the Myako and Yonaguni islands. Since ∼10 Ma, the tear continuously progressed westward within EU crust, with the Philippine Sea plate progressively subducting northwestward between the two lips of the tear fault. A RFF (ridge-fault-fault) triple junction was active in the EU crust before 20.5 Ma, from 10 to 7 Ma, and since 2 Ma. This triple junction was always located on the MTF with one branch of the MTF on each side of the triple junction, and the third branch being the spreading center.</p></div>\",\"PeriodicalId\":22257,\"journal\":{\"name\":\"Tectonophysics\",\"volume\":\"884 \",\"pages\":\"Article 230397\"},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-06-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Tectonophysics\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0040195124001999\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Tectonophysics","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0040195124001999","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
摘要
我们介绍了对东南亚地球动力学的最新评估,包括自 20.5-18 Ma SCS扩张结束以来南海边缘盆地与周边板块的相互作用。在南中国海东海盆消亡扩张中心附近的 IODP U1431 钻探到的南中国海大洋地壳的 Ar39/Ar40 新年龄早于 18 Ma。相反,位于台湾兰屿、海岸山脉和利吉混杂区的吕宋岛弧和前弧的最古老年龄为17-18 Ma,表明马尼拉俯冲带的形成可能要早几 m.y.。在 20.5 Ma 以前,马尼拉横断面(MTF)的北部被认为是琉球俯冲带的西部边界,是一个左侧岩石圈尺度的剪切带。从 20.5-18 Ma 到 7 Ma,MTF 的这一部分与马尼拉海沟相连。自 ∼7 Ma 起,MTF 延伸至台湾纵谷,并继续向南延伸至吕宋岛北部,成为近垂直的左侧剪切带。如今,在北纬24°以南,MTF向下延伸至30千米深处,并终止于更深的马尼拉板块之上。自∼7 Ma以来,整个MTF相对于欧亚大陆西移了400 km,并顺时针旋转了∼23°,在北纬16°以北变成了∼NS方向。我们在琉球海沟以北的欧亚(EU)板块中发现了一个撕裂断层,该断层位于妙古岛和与那国岛以南。自 ∼10 Ma 以来,撕裂断层在欧盟地壳内不断向西推进,菲律宾海板块在撕裂断层的两唇之间逐渐向西北俯冲。在20.5Ma以前、10-7Ma期间以及2Ma以来,欧盟地壳中活跃着一个RFF(海岭-断层-断层)三重交界处。该三交界处始终位于MTF上,MTF的一个分支位于三交界处的两侧,第三个分支是扩张中心。
A revolution in understanding SE Asia geodynamics since 20.5–18 Ma
We present an updated evaluation of SE Asian geodynamics that includes the interactions of the South China Sea (SCS) marginal basin with surrounding plates since the end of SCS spreading 20.5–18 Ma. Newly available Ar39/Ar40 ages of SCS oceanic crust drilled at IODP U1431 near the SCS East basin extinct spreading center are older than 18 Ma. Conversely, the oldest ages of the Luzon arc and forearc at Taiwan's Lanyu island, Coastal range and Lichi mélange are 17–18 Ma, suggesting that onset of the Manila subduction zone may have begun a few m.y. earlier. Before ∼20.5 Ma, the northern part of the Manila transcurrent fault (MTF), considered as the western boundary of the Ryukyu subduction zone, was a left-lateral lithospheric-scale shear zone. From ∼20.5–18 Ma to ∼7 Ma, this portion of MTF was connected to the Manila trench. Since ∼7 Ma, the MTF extended into the Taiwan Longitudinal valley and continued southwards to north Luzon island as near-vertical, left-lateral shear zone. Today, south of ∼24°N, the MTF protrudes down to 30 km depths and terminates above the deeper Manila slab. Since ∼7 Ma, the whole MTF shifted 400 km westward with respect to Eurasia and rotated ∼23° clockwise to become oriented ∼NS north of 16°N latitude. We identify a tear fault in the Eurasian (EU) plate north of the Ryukyu trench that is located south of the Myako and Yonaguni islands. Since ∼10 Ma, the tear continuously progressed westward within EU crust, with the Philippine Sea plate progressively subducting northwestward between the two lips of the tear fault. A RFF (ridge-fault-fault) triple junction was active in the EU crust before 20.5 Ma, from 10 to 7 Ma, and since 2 Ma. This triple junction was always located on the MTF with one branch of the MTF on each side of the triple junction, and the third branch being the spreading center.
期刊介绍:
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