Magnetic anomalies in the Eastern Caribbean
Magnetic anomalies in the Eastern Caribbean
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DOI：
10.1007/s00531-012-0828-6
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发表时间：
2013-04
影响因子：
2.3
通讯作者：
Nuris Orihuela Guevara;Andreina García;Mariano Arnaiz
中科院分区：
文献类型：
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作者：
Nuris Orihuela Guevara;Andreina García;Mariano Arnaiz
尽管对加勒比板块的起源和演化有许多不同的研究，但迄今为止还没有任何建议被广泛接受。这一研究领域的一个关键要素是确定板块地下洋壳的特征，因为这将澄清它起源的条件、形成的地质时期及其在第一个演化阶段可能的地理位置。根据部分研究结果，可以说前人的研究结论在很大程度上是正确的，即委内瑞拉盆地西段条带状磁异常为NE-SW向，存在平行于背风安的列斯群岛的W-E向优先条带。委内瑞拉盆地东南部三角形剖面的磁响应代表白垩纪磁静区（CMQZ），因此显示出相当大的条纹图案衰减，表明整个东加勒比地下具有洋壳物质。对于加勒比海磁条记录的周期，我们提出了M23和M0时之间的间隔，以及CMQZ的一部分。已查明的异常现象的波长表明，与目前活跃海脊的平均水平相比，与加勒比洋底形成有关的海脊扩展缓慢。
Despite the many different studies on the origin and evolution of the Caribbean Plate, no proposal has been widely accepted so far. A key element within this field of research is the characterization of the plate subsurface oceanic crust, as it would clarify the conditions in which it originated, the geological period when it formed and its possible geographical location at this first evolution stage. Based on partial results of this research work, we can say that the conclusions of previous studies are valid to a great extent, namely the NE–SW orientation of the striped magnetic anomalies in the Venezuelan Basin’s western section and the existence of W–E preferentially oriented stripes parallel to the Leeward Antilles. The magnetic response of the triangular section in the southeast of the Venezuelan Basin represents cretaceous magnetic quiet zone (CMQZ) and therefore shows a considerable attenuation of the stripe pattern, indicating that the whole East Caribbean subsurface features oceanic crustal material. As for the period recorded by the Caribbean magnetic stripes, we propose the interval between chrons M23 and M0, and part of CMQZ. The wavelengths of the identified anomalies suggest that the ridge associated with the formation of Caribbean ocean floor was slow-spreading when compared to average currently active ridges.