Structure and deformation of the Kermadec forearc in response to subduction of the Pacific oceanic plate
Structure and deformation of the Kermadec forearc in response to subduction of the Pacific oceanic plate
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克马德克弧前的结构和变形对太平洋板块俯冲的响应
DOI：
10.1093/gji/ggu330
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发表时间：
2014
影响因子：
2.8
通讯作者：
Funnell M
中科院分区：
文献类型：
--
作者：
Funnell M
汤加-克马德克前弧正在变形，以响应太平洋板块在印度-澳大利亚板块之下的持续俯冲。以前的研究集中于弧前的结构发展，在那里，希库朗吉高原和路易斯维尔岭海山链等大型测深特征正在俯冲。因此，在正常板块会聚区域的“背景”前弧的知识是有限的。本文报道了一条250公里长的多道地震反射剖面，该剖面垂直于汤加-Kermadec海沟，在南纬128 °处拍摄，以确定Kermadec前弧的结构、地层和变形的横向和时间变化，这些变化完全是太平洋板块俯冲的结果。太平洋板块表现出地垒和地堑结构，以适应弯曲引起的伸展应力，产生的地壳向沟倾斜增加。沟槽填充物也比预期的厚1公里，我们认为，结果增加沉积物通量进入和沿着沟槽。普遍存在的正常断层的中沟斜坡最有可能容纳大部分的观察到的弧前延伸基底俯冲侵蚀的反应，和一个结构高位于中，上沟斜坡之间。我们认为这个高度代表了位于该区域下方的一个致密的、最有可能是结构坚固的地壳区域。上海沟斜坡的沉积物记录了沉积间断和弧的持续隆起。强烈的沿弧电流似乎侵蚀了Kermadec火山弧，并将沉积物分布到周围的盆地，而弧前电流则将沉积物重新分布为沉积物波。就在剖面北部观察到的过渡性Kermadec前弧的轻微隆起，似乎与一个潜在的结构趋势以及向北250公里的路易斯维尔岭海山链的俯冲有关。克马德克弧的相对隆起是从上海沟斜坡沉积物的倾斜变化和路易斯维尔山脊周围基底的伸展断层中观察到的。
The Tonga-Kermadec forearc is deforming in response to on-going subduction of the Pacific Plate beneath the Indo-Australian Plate. Previous research has focussed on the structural development of the forearc where large bathymetric features such as the Hikurangi Plateau and Louisville Ridge seamount chain are being subducted. Consequently, knowledge of the ‘background’ forearc in regions of normal plate convergence is limited. We report on an ∼250-km-long multichannel seismic reflection profile that was shot perpendicular to the Tonga-Kermadec trench at ∼28°S to determine the lateral and temporal variations in the structure, stratigraphy and deformation of the Kermadec forearc resulting solely from Pacific Plate subduction.Interpretation of the seismic profile, in conjunction with regional swath bathymetry data, shows that the Pacific Plate exhibits horst and graben structures that accommodate bending-induced extensional stresses, generated as the trenchward dip of the crust increases. Trench infill is also much thicker than expected at 1 km which, we propose, results from increased sediment flux into and along the trench. Pervasive normal faulting of the mid-trench slope most likely accommodates the majority of the observed forearc extension in response to basal subduction erosion, and a structural high is located between the mid- and upper-trench slopes. We interpret this high as representing a dense and most likely structurally robust region of crust lying beneath this region.Sediment of the upper-trench slope documents depositional hiatuses and on-going uplift of the arc. Strong along-arc currents appear to erode the Kermadec volcanic arc and distribute this sediment to the surrounding basins, while currents over the forearc redistribute deposits as sediment waves. Minor uplift of the transitional Kermadec forearc, observed just to the north of the profile, appears to relate to an underlying structural trend as well as subduction of the Louisville Ridge seamount chain 250 km to the north. Relative uplift of the Kermadec arc is observed from changes in the tilt of upper-trench slope deposits and extensional faulting of the basement immediately surrounding the Louisville Ridge.
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西南太平洋路易斯维尔热点链的地理和历史
DOI：
--
发表时间：
1988
期刊：
影响因子：
--
作者：
P. Lonsdale
通讯作者：
P. Lonsdale
高频（3.5–12 kHz）回波图在深海近海底沉积过程研究中的应用：综述☆
DOI：
--
发表时间：
1980
期刊：
影响因子：
--
作者：
J. Damuth
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J. Damuth
DOI：
10.1007/bf02084016
发表时间：
1986-12
期刊：
Marine Geophysical Researches
影响因子：
--
作者：
P. Lonsdale
通讯作者：
P. Lonsdale
影响因子：
3.9
作者：
Contreras-Reyes, Eduardo;Grevemeyer, Ingo;Papenberg, Cord
通讯作者：
Papenberg, Cord
与弧裂谷、俯冲侵蚀和山脊碰撞相关的汤加弧前沉积：站点 840 和 841 结果的综合
影响因子：
5.8
作者：
P. Clift;U. Bednarz;R. Bøe;R. G. Rothwell;R. Hodkinson;J. Ledbetter;C. Pratt;S. Soakai
通讯作者：
S. Soakai