期刊
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
卷 16, 期 12, 页码 4261-4274出版社
AMER GEOPHYSICAL UNION
DOI: 10.1002/2015GC006100
关键词
magnetotellurics; western Mediterranean; subduction; roll-back
资金
- NSF [EAR080-9074]
- Spanish National Projects [CTM2009-07039-E/MAR, CTM2011-30400-C02-02]
- Repsol
- ICREA Funding Source: Custom
We present results of marine MT acquisition in the Alboran sea that also incorporates previously acquired land MT from southern Spain into our analysis. The marine data show complex MT response functions with strong distortion due to seafloor topography and the coastline, but inclusion of high resolution topography and bathymetry and a seismically defined sediment unit into a 3-D inversion model has allowed us to image the structure in the underlying mantle. The resulting resistivity model is broadly consistent with a geodynamic scenario that includes subduction of an eastward trending plate beneath Gibraltar, which plunges nearly vertically beneath the Alboran. Our model contains three primary features of interest: a resistive body beneath the central Alboran, which extends to a depth of approximate to 150 km. At this depth, the mantle resistivity decreases to values of approximate to 100 Ohm-m, slightly higher than those seen in typical asthenosphere at the same depth. This transition suggests a change in slab properties with depth, perhaps reflecting a change in the nature of the seafloor subducted in the past. Two conductive features in our model suggest the presence of fluids released by the subducting slab or a small amount of partial melt in the upper mantle (or both). Of these, the one in the center of the Alboran basin, in the uppermost-mantle (20-30 km depth) beneath Neogene volcanics and west of the termination of the Nekkor Fault, is consistent with geochemical models, which infer highly thinned lithosphere and shallow melting in order to explain the petrology of seafloor volcanics.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据