Dextral shear, terrane accretion and basin formation in the Northern Andes: best explained by interaction with a Pacific-derived Caribbean Plate?
Dextral shear, terrane accretion and basin formation in the Northern Andes: best explained by interaction with a Pacific-derived Caribbean Plate?
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安第斯山脉北部的右旋剪切、地体增生和盆地形成：最好的解释是与太平洋衍生的加勒比板块的相互作用？
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Pindell
中科院分区：
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作者：
L. Kennan;J. Pindell
北方秘鲁、厄瓜多尔和哥伦比亚的构造、地层和岩浆历史只能用加勒比板块的太平洋起源模式来充分解释。加勒比板块起源的美洲模型不能解释北方安第斯山脉和中部安第斯山脉之间的对比。安第斯山脉中部以持续的大规模俯冲、弧岩浆作用和挤压变形为特征，而北方安第斯山脉则表现为弧后盆地和被动边缘形成，随后是大洋高原玄武岩和与加勒比海相似的岛弧玄武岩的右斜向增生。白垩纪南北美洲的分离导致加勒比海和南美洲西北部之间的北北东向右旋-逆冲边界的发展，当原始加勒比海道的扩张在白垩纪末期放缓时，挤压性变得更强。右旋平移挤压开始于120-100 Ma，加勒比弧在加勒比板块的前缘形成，这是由于在先前存在的横贯美洲弧的位置处俯冲带极性逆转的结果，该弧在今天的秘鲁-厄瓜多尔边界附近连接中美洲和南美洲。随后安第斯弧后盆地的闭合导致加勒比地体向哥伦比亚西部增生。在大约100 Ma时，加勒比板块在哥伦比亚下方的平板俯冲开始与有限的岩浆活动有关，随后没有岩浆弧的发展。随后是向北延伸的马斯特里赫特期至始新世碰撞的后缘巴拿马弧。巴拿马弧连接秘鲁-智利海沟的三重连接点晚至始新世时位于现今厄瓜多尔的西部，而塔拉拉、通贝斯和马纳比拉分盆地与其向北迁移直接相关。与纳斯卡板块俯冲有关的特征，如建立在南美洲地壳上的活跃钙碱性火山弧，只在厄瓜多尔建立，然后是哥伦比亚，因为三联点向北迁移。我们的模型为分析北方安第斯山脉弧遗迹、基底块体和盆地的拼贴提供了一个全面的、区域性的和可检验的框架。
Abstract The structure, stratigraphy and magmatic history of northern Peru, Ecuador and Colombia are only adequately explained by Pacific-origin models for the Caribbean Plate. Inter-American models for the origin of the Caribbean Plate cannot explain the contrasts between the Northern Andes and the Central Andes. Persistent large magnitude subduction, arc magmatism and compressional deformation typify the Central Andes, while the Northern Andes shows back-arc basin and passive margin formation followed by dextral oblique accretion of oceanic plateau basalt and island arc terranes with Caribbean affinity. Cretaceous separation between the Americas resulted in the development of a NNE-trending dextral–transpressive boundary between the Caribbean and northwestern South America, becoming more compressional when spreading in the Proto-Caribbean Seaway slowed towards the end of the Cretaceous. Dextral transpression started at 120–100 Ma, when the Caribbean Arc formed at the leading edge of the Caribbean Plate as a result of subduction zone polarity reversal at the site of the pre-existing Trans-American Arc, which had linked to Central America to South America in the vicinity of the present-day Peru–Ecuador border. Subsequent closure of the Andean Back-Arc Basin resulted in accretion of Caribbean terranes to western Colombia. Initiation of flat-slab subduction of the Caribbean Plate beneath Colombia at about 100 Ma is associated with limited magmatism, with no subsequent development of a magmatic arc. This was followed by northward-younging Maastrichtian to Eocene collision of the trailing edge Panama Arc. The triple junction where the Panama Arc joined the Peru–Chile trench was located west of present-day Ecuador as late as Eocene time, and the Talara, Tumbes and Manabi pull-apart basins directly relate to its northward migration. Features associated with the subduction of the Nazca Plate, such as active calc-alkaline volcanic arcs built on South American crust, only became established in Ecuador, and then Colombia, as the triple junction migrated to the north. Our model provides a comprehensive, regional and testable framework for analysing the as yet poorly understood collage of arc remnants, basement blocks and basins in the Northern Andes.