Diking of various slab melts beneath forearc spreading center and age constraints of the subducted slab
Diking of various slab melts beneath forearc spreading center and age constraints of the subducted slab
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弧前扩张中心下各种板片熔体的围堤和俯冲板片的年龄限制
DOI：
10.1016/j.epsl.2022.117367
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发表时间：
2022-02
影响因子：
5.3
通讯作者：
Chi-Yue Huang
中科院分区：
文献类型：
--
作者：
Mengming Yu;Graciano P. Yumul Jr.;Yildirim Dilek;Yi Yan;Chi-Yue Huang
为了更好地理解俯冲带的建立，需要对各种因素进行相当大的努力，例如俯冲开始的时间和板块岩石圈的年龄。在这项研究中，埃达克岩脉（约。17.3 Ma：εNd = 7.4-7.9，206 Pb/204 Pb = 18.27-18.42）与正常洋中脊玄武岩（N-和E-MORB）和富集洋中脊玄武岩（E-MORB）类洋壳（约200 - 200 Ma）一起沿着结晶。17.8- 14.1Ma：εNd = 8.8-13.3，206Pb/204Pb = 17.71-18.22）。鉴于出露于超基性岩系中，Nd-Pb同位素特征明显，且比相应的弧火山作用（≤ ca. 14.1因此，ETO埃达克岩脉的成因与吕宋弧前扩张中心俯冲板片在俯冲初始阶段的角闪岩相熔融有关。在这方面，我们得出结论：E-MORB型岩石（εNd = 8.8-10.2，206 Pb/204 Pb = 18.06-18.22）为富Nb玄武岩，与年轻南海俯冲板片热榴辉岩残余物进一步熔融形成的富Nb板片熔体有关。此外，N-MORB类样品的同位素多样性可以归因于埃达克质和富Nb板片熔体的吕宋岛弧前扩张中心之下的筑堤。结合先前报道的早中新世吕宋岛西部赞巴莱蛇绿岩的隆升，我们推断早中新世南海的俯冲启动和吕宋岛前弧在<5 Myr. Compared to the absence of Nb-enriched slab melts and >原地伊豆-博宁-马里亚纳（IBM）前弧和大量富铌岩石和钙的成因中被2000万年的俯冲板片延迟的近海沟扩张。中巴拉望-阿姆奈蛇绿岩的000万年俯冲板片、稀的富铌岩石和ETO序列的<1500万年俯冲板片都是俯冲启动岩浆作用期间板片岩石圈年龄的控制因素。我们建议，在阿曼蛇绿岩弧前化学地层学中缺乏富铌板状熔体可能表明一个古老而寒冷的大洋板块的俯冲开始。
To better understand the establishment of subduction zones, considerable effort is required regarding various factors, such as the time of subduction initiation and the age of the slab's lithosphere. In this study, adakitic dikes (ca. 17.3 Ma:εNd of 7.4–7.9 and206Pb/204Pb of 18.27–18.42) were recognized to crystallize along with the normal and enriched mid-ocean ridge basalt (N- and E-MORB)-like oceanic crust (ca. 17.8–14.1 Ma:εNd of 8.8–13.3 and206Pb/204Pb of 17.71–18.22) in the East Taiwan Ophiolite (ETO). Given that the outcropping in ultramafic sequence, the distinct Nd–Pb isotopes, and the slight precedence than corresponding arc volcanism (≤ ca. 14.1 Ma), the origins of the ETO adakitic dikes are related to amphibolite-facies melting of the subducted slab beneath the Luzon forearc spreading center during subduction initiation. In this respect, we conclude that the sparsely exposed but isotopically heterogeneous E-MORB-type rocks (εNd of 8.8–10.2 and206Pb/204Pb of 18.06–18.22) are Nb-enriched basalts and relate to the Nb-enriched slab melts derived from further melting of the hot eclogitic residuum of the young South China Sea subducted slab. In addition, the isotopic diversity of N-MORB-like samples can be attributed to the diking of adakitic and Nb-enriched slab melts beneath the Luzon forearc spreading center. Combined with the previously reported early Miocene uplift of the Zambales Ophiolite in the western Luzon, we infer an early Miocene induced-subduction initiation of the South China Sea and the delayed near-trench spreading of the Luzon forearc by <5 Myr. Compared to the absence of Nb-enriched slab melts and >20 Myr subducted slab in the genesis of thein-situIzu-Bonin-Mariana (IBM) forearc and the voluminous Nb-enriched rocks and ca. 0 Myr subducted slab of the Central Palawan–Amnay ophiolites, the sparse Nb-enriched rocks and <15 Myr subducted slab of the ETO sequence invoke the governing factor of slab's lithosphere age during subduction initiation magmatism. We propose that the lack of Nb-enriched slab melts in the forearc chemostratigraphy of the Oman Ophiolite may indicate the subduction initiation of an old and cold oceanic plate.
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DOI：
10.3319/tao.2019.06.19.01
发表时间：
2020
期刊：
Terrestrial, Atmospheric and Oceanic Sciences
影响因子：
--
作者：
Yun-Chieh Lo;Chih‐Tung Chen;C. Lo;Sun‐Lin Chung
通讯作者：
Yun-Chieh Lo;Chih‐Tung Chen;C. Lo;Sun‐Lin Chung
影响因子：
5.3
作者：
Guoliang Zhang;Qing Luo;Jian Zhao;M. Jackson;Lishuang Guo;Li-feng Zhong
通讯作者：
Guoliang Zhang;Qing Luo;Jian Zhao;M. Jackson;Lishuang Guo;Li-feng Zhong
影响因子：
3.5
作者：
S. Whattam;R. Stern
通讯作者：
S. Whattam;R. Stern
影响因子：
5.8
作者：
A. Draut;P. Clift
通讯作者：
A. Draut;P. Clift
影响因子：
5.8
作者：
R. Larson
通讯作者：
R. Larson