The Caribbean and Farallon Plates Connected: Constraints From Stratigraphy and Paleomagnetism of the Nicoya Peninsula, Costa Rica
The Caribbean and Farallon Plates Connected: Constraints From Stratigraphy and Paleomagnetism of the Nicoya Peninsula, Costa Rica
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DOI：
10.1029/2018jb016369
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发表时间：
2019-07-01
影响因子：
3.9
通讯作者：
van Hinsbergen, D. J. J.
中科院分区：
文献类型：
--
作者：
Boschman, L. M.;van der Wiel, E.;van Hinsbergen, D. J. J.
板块运动重建在我们理解全球地球动力学方面发挥着重要作用，但由于海洋岩石圈的俯冲，板块运动重建变得越来越难以限制在地质时期。在这里，我们尝试从运动学角度重建中生代 Panthalassa（古太平洋）洋内加勒比板块的白垩纪和更古老的板块构造历史。为此，我们提供了来自哥斯达黎加西北部尼科亚半岛和Murcielago群岛侏罗纪和白垩纪海洋沉积物和火山大型火成岩省相关岩石的新古地磁数据。我们利用这些数据，结合海洋磁异常的约束来推断岩石圈基底的年龄，结合地震层析成像来定位深部地幔羽流生成区，以及一般的运动学可行性，以测试从太平洋扩张记录中恢复的连接加勒比板块和法拉隆板块的不同重建场景。我们的重建结果表明，西加勒比俯冲带在大洋内环境中于 100 Ma 左右开始，破坏了至少 70 Myr 年龄的海洋岩石圈。
Plate kinematic reconstructions play an essential role in our understanding of global geodynamics, but become increasingly difficult to constrain back in geological time due to the subduction of oceanic lithosphere. Here, we attempt to kinematically reconstruct the Cretaceous and older plate tectonic history of the Caribbean Plate within the Mesozoic Panthalassa (paleo-Pacific) Ocean. To this end, we present new paleomagnetic data from Jurassic and Cretaceous oceanic sedimentary and volcanic Large Igneous Province-related rocks of the Nicoya Peninsula and Murcielago Islands of northwestern Costa Rica. We use these data, in combination with constraints from marine magnetic anomalies to infer the age of the lithospheric basement, seismic tomography to locate deep-mantle plume generation zones, and general kinematic feasibility, to test different reconstruction scenarios connecting the Caribbean Plate to the Farallon Plate as restored from Pacific spreading records. Our resulting reconstruction implies that the western Caribbean subduction zone initiated around 100 Ma, in an intraoceanic setting, breaking up oceanic lithosphere of at least 70 Myr old.