Petrogenesis of meta-volcanic rocks from the Maimón Formation (Dominican Republic): Geochemical record of the nascent Greater Antilles paleo-arc
Petrogenesis of meta-volcanic rocks from the Maimón Formation (Dominican Republic): Geochemical record of the nascent Greater Antilles paleo-arc
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迈蒙组变质火山岩的岩石成因（多米尼加共和国）：新生大安的列斯群岛古弧的地球化学记录
DOI：
10.1016/j.lithos.2017.01.031
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发表时间：
2017
期刊：
影响因子：
3.5
通讯作者：
J. Lewis
中科院分区：
文献类型：
--
作者：
L. Torró;J. Proenza;C. Marchesi;A. Garcia‐Casco;J. Lewis
位于多米尼加共和国中部科迪勒拉的早白垩世可能是前阿尔比亚-迈蒙建造的变质玄武岩、玄武岩安山岩、安山岩和斜长玄武岩是大安的列斯弧岩浆作用的早期产物。本文利用新的全岩元素和Nd-Pb放射性同位素资料，对深成变质火山岩的成因进行了新的认识，并对大安的列斯古弧系的早期演化进行了约束。根据镁铁质火山岩中不动元素的含量，划分出三组不同的镁铁质火山岩。第一类玄武岩的成分类似于低钛岛弧拉斑玄武岩(IAT)，亏损轻稀土元素(LREE)，类似于Izu-Bonin-Mariana前弧的弧前玄武岩(Fab)和过渡的Fab-Boninitic玄武岩。第二组岩石具有类玻安岩成分，相对富铬，贫二氧化钛。组3为低钛岛弧拉斑玄武岩，稀土配分模式接近平坦球粒陨石。斜长花岗岩和稀有安山岩呈现近平坦到微妙的LREE亏损的球粒陨石标准化模式，具有典型的拉斑玄武岩亲和性。斜长高岭岩的Nd、Pb同位素比值与1、3组玄武岩相似，支持这些长英质熔岩是由弧形下地壳深熔形成的。地球化学模拟表明，马尼翁变火山岩的母基性岩浆是由类似于亏损的MORB地幔(DMM)或亏损的DMM(D-DMM)的非均质尖晶石相地幔源区的水合熔融形成的，受到俯冲洋壳和大西洋白垩纪远洋沉积的流体的影响。从第1组到第2组和第3组年轻岩石的俯冲敏感元素浓度和比值的变化通常与俯冲开始蛇绿岩中描述的从类FAB到玻安岩和IAT熔岩的地球化学过程相一致。第一类玄武岩可能形成于FAB与第一岛弧岩浆作用过渡的岩浆阶段，而第二类博尼质熔岩可能是在较成熟的俯冲阶段集中熔融和较高的熔体提取程度而形成的。第三组玄武岩可能代表了在稳定俯冲体制建立之前发生的岩浆作用。在Maimón熔岩中记录到的相对较高程度的熔剂熔化和板岩输入支持了新生的大安的列斯古弧下的热俯冲情景。古构造重建和明显亏损的地幔源区虽然不均匀，但表明在南西向俯冲开始之前，在原加勒比海区域已经有来自大洋中脊玄武岩(MORB)和(或)弧后盆地玄武岩(BABB)的浅软流圈的上升。相对于邻近的Aptian-Albian Los Ranchos组，我们认为Maimón火山岩更靠近俯冲的原加勒比海扩张脊的垂直投影。
Metamorphosed basalts, basaltic andesites, andesites and plagiorhyolites of the Early Cretaceous, probably pre-Albian, Maimón Formation, located in the Cordillera Central of the Dominican Republic, are some of the earliest products of the Greater Antilles arc magmatism. In this article, new whole-rock element and Nd–Pb radiogenic isotope data are used to give new insights into the petrogenesis of the Maimón meta-volcanic rocks and constrain the early evolution of the Greater Antilles paleo-arc system. Three different groups of mafic volcanic rocks are recognized on the basis of their immobile element contents. Group 1 comprises basalts with compositions similar to low-Ti island arc tholeiites (IAT), which are depleted in light rare earth elements (LREE) and resemble the forearc basalts (FAB) and transitional FAB-boninitic basalts of the Izu-Bonin-Mariana forearc. Group 2 rocks have boninite-like compositions relatively rich in Cr and poor in TiO2. Group 3 comprises low-Ti island arc tholeiitic basalts with near-flat chondrite-normalized REE patterns. Plagiorhyolites and rare andesites present near-flat to subtly LREE-depleted chondrite normalized patterns typical of tholeiitic affinity. Nd and Pb isotopic ratios of plagiorhyolites, which are similar to those of Groups 1 and 3 basalts, support that these felsic lavas formed by anatexis of the arc lower crust.Geochemical modelling points that the parental basic magmas of the Maimón meta-volcanic rocks formed by hydrous melting of a heterogeneous spinel-facies mantle source, similar to depleted MORB mantle (DMM) or depleted DMM (D-DMM), fluxed by fluids from subducted oceanic crust and Atlantic Cretaceous pelagic sediments. Variations of subduction-sensitive element concentrations and ratios from Group 1 to the younger rocks of Groups 2 and 3 generally match the geochemical progression from FAB-like to boninite and IAT lavas described in subduction-initiation ophiolites. Group 1 basalts likely formed at magmatic stages transitional between FAB and first-island arc magmatism, whereas Group 2 boninitic lavas resulted from focused flux melting and higher degrees of melt extraction in a more mature stage of subduction. Group 3 basalts probably represent magmatism taking place immediately before the establishment of a steady-state subduction regime. The relatively high extents of flux melting and slab input recorded in the Maimón lavas support a scenario of hot subduction beneath the nascent Greater Antilles paleo-arc. Paleotectonic reconstructions and the markedly depleted, though heterogeneous character of the mantle source, indicate the rise of shallow asthenosphere which had sourced mid-ocean ridge basalts (MORB) and/or back-arc basin basalts (BABB) in the proto-Caribbean domain prior to the inception of SW-dipping subduction. Relative to the neighbouring Aptian-Albian Los Ranchos Formation, we suggest that Maimón volcanic rocks extruded more proximal to the vertical projection of the subducting proto-Caribbean spreading ridge.
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影响因子：
3.5
作者：
I. Blanco-Quintero;Y. Rojas‐Agramonte;A. Garcia‐Casco;A. Kröner;D. Mertz;C. Lázaro;J. Blanco-Moreno-J.-Blanco
通讯作者：
I. Blanco-Quintero;Y. Rojas‐Agramonte;A. Garcia‐Casco;A. Kröner;D. Mertz;C. Lázaro;J. Blanco-Moreno-J.-Blanco
影响因子：
3.9
作者：
A. Garcia‐Casco;C. Lázaro;Y. Rojas‐Agramonte;A. Kröner;R. Torres-Roldán;Kenya Núñez;F. Neubauer;G. Millán;I. Blanco-Quintero
通讯作者：
A. Garcia‐Casco;C. Lázaro;Y. Rojas‐Agramonte;A. Kröner;R. Torres-Roldán;Kenya Núñez;F. Neubauer;G. Millán;I. Blanco-Quintero
古巴中部白垩纪岛弧岩浆作用的时间和演化：对西北加勒比地区弧系统历史的影响
DOI：
10.1086/662033
发表时间：
2011
期刊：
The Journal of Geology
影响因子：
--
作者：
Rojas-Agramonte;Kröner;García-Casco;Iturralde-Vinent;Mattinson;Millán Trujillo;Pérez Rodríguez;Carrasquilla-Ortiz;Wingate
通讯作者：
Wingate
加勒比板块北缘5500万年海洋俯冲和折返历史（古巴Sierra del Convento mélange）
影响因子：
3.4
作者：
Lázaro;García-Casco;Rojas-Agramonte;Kröner;Neubauer;Turralde-Vinent
通讯作者：
Turralde-Vinent