Demerara Rise, offshore Suriname: Magma-rich segment of the Central Atlantic Ocean, and conjugate to the Bahamas hot spot
Demerara Rise, offshore Suriname: Magma-rich segment of the Central Atlantic Ocean, and conjugate to the Bahamas hot spot
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苏里南近海德梅拉拉海隆：大西洋中部岩浆丰富的部分，与巴哈马热点相连
DOI：
10.1190/int-2014-0246.1
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发表时间：
2016
期刊：
影响因子：
0.3
通讯作者：
B. Horn
中科院分区：
文献类型：
--
作者：
K. Reuber;J. Pindell;B. Horn
摘要德梅拉拉隆起是一个突出的测深特征，被认为是浅大陆基底的广泛表达，并与几内亚高原一起作为环大西洋板块重建的钉扎点。以前，在德梅拉拉隆起的浅穿透，成像差的地震数据进行建模与较低的序列解释为大陆地壳在相对较浅的深度。然而，新的长偏移距、深穿透地震数据提供的证据表明，基底几乎或完全由极厚的火山岩层（约21公里）组成。地震特征和几何，二维重力模拟，火山边缘类似物被用来识别无断层，凸向上向海倾斜反射（SDR）包。这些陡倾（约20°）的火成岩序列是西向发散的，并且以长达250 km的列状叠置反射体的形式出现。这种裂谷相关的火山活动，现在承认在德梅拉拉上升可能共轭…
AbstractThe Demerara Rise is a prominent bathymetric feature that has been considered as a broad expression of shallow continental basement and used in conjunction with the Guinea Plateau as a pinning point for circum-Atlantic plate reconstructions. Previously, shallow-penetration, poorly imaged seismic data over the Demerara Rise were modeled with the lower sequences interpreted as continental crust at relatively shallow depths. However, new long-offset, deeply penetrating seismic data provide evidence that basement nearly or entirely comprises excessively thick volcanic strata (approximately 21 km). Seismic character and geometry, 2D gravity modeling, and volcanic margin analogs were used to identify unfaulted, convex-upward seaward dipping reflector (SDR) packages. These steeply dipping (approximately 20°) igneous successions are westwardly divergent, and occur as offlapping reflector sets in trains as long as 250 km. This rift-related volcanism now recognized at the Demerara Rise was probably conjugat...