The single largest oceanic plateau: Ontong Java–Manihiki–Hikurangi
The single largest oceanic plateau: Ontong Java–Manihiki–Hikurangi
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DOI：
10.1016/j.epsl.2005.11.049
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发表时间：
2006-01
影响因子：
5.3
通讯作者：
B. Taylor
中科院分区：
文献类型：
--
作者：
B. Taylor
大洋高原是镁铁质火成岩省份，通常被认为是从上升的地幔热柱中衍生出来的。到目前为止，最大的是安通爪哇高原(OJP)，侵位时间约为120 Ma，而岩浆脉动要小得多，约为90 Ma。Manihiki和Hikurangi高原(MP和HP)年龄和成分相似，在白垩纪漫长的正常地磁时期形成的洋盆将其与OJP分开。我提供了新的海底组构数据，表明三个高原形成为一个高原(OJMHP)。这些数据支持以前的解释，即奥斯本海槽是分隔MP和HP的扩张中心的残余，但它们需要与埃利斯盆地的主流构造模型不同的解释。埃利斯盆地中紧密分布的、大偏移距的断裂带限制了分隔OJP和MP的前右台阶扩张段。MP被部署在太平洋-凤凰岭的轴线附近，以前在其东部边缘有更多的高原碎片。在OJMHP解体后，海底扩张将这些碎片带到了东部和SSE，以及与现存的菲尼克斯磁性线理的对称共轭。
Oceanic plateaus are mafic igneous provinces commonly thought to derive from ascending mantle plumes. By far the largest, the Ontong Java Plateau (OJP) was emplaced ca. 120 Ma, with a much smaller magmatic pulse of ca. 90 Ma. Of similar age and composition, the Manihiki and Hikurangi Plateaus (MP and HP) are separated from the OJP by ocean basins formed during the Cretaceous long normal magnetic period. I present new seafloor fabric data that indicate the three plateaus formed as one (OJMHP). The data support previous interpretations that the Osbourn Trough is the relict of the spreading center that separated the MP and HP but they require a different interpretation than prevailing tectonic models for the Ellice Basin. Closely spaced, large offset, fracture zones in the Ellice Basin bound former right-stepping spreading segments that separated the OJP and MP. The MP was emplaced near the axis of the Pacific–Phoenix ridge and additional plateau fragments formerly bordered its eastern margins. Following OJMHP break-up, seafloor spreading removed these fragments to the east and SSE, together with the symmetric conjugates to the extant Phoenix magnetic lineations.