Temporal and spatial cyclicity of accretion at slow-spreading ridges—evidence from the Reykjanes Ridge.
Temporal and spatial cyclicity of accretion at slow-spreading ridges—evidence from the Reykjanes Ridge.
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缓慢扩张的山脊吸积的时间和空间周期性——来自雷克雅内斯山脊的证据。
DOI：
10.1111/j.1365-246x.2005.02738.x
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发表时间：
2005
影响因子：
2.8
通讯作者：
M. Sinha
中科院分区：
文献类型：
--
作者：
C. Peirce;A. Gardiner;M. Sinha
本文提出了一个以缓慢扩张速率发展海洋地壳的统一模型，其中，增生遵循岩浆建造和构造破坏的循环模式，受熔体供应的沿轴变化控制，并与扩张速率的沿轴变化和扩张的跨轴不对称性相耦合。本研究的重点是冰岛以南的中大西洋海脊雷克雅内斯海脊，该海脊沿其整个长度沿着被分成许多轴向火山海脊（AVR）。已经分析了五个相邻的AVR，位于北纬57度30分至58度30分之间，以及任何强烈的冰岛热点影响的南部。每个AVR的海底形态进行了调查，使用侧扫声纳数据，以确定相对年龄和喷发的历史。每个AVR的沿轴重力剖面相对于地震导出的地壳参考模型进行建模，以揭示底层地壳厚度和密度结构。将这些模型与海底特征、地壳结构、海脊段形态和相对年龄相关联，建立了一个周期性海脊分段模型，其中加积导致具有一系列地壳特征的相邻AVR，从总体上看，雷克雅未克海脊的二级段沿轴向长度为1070公里，包括几个相邻的AVR，反映了三级分割的模式。构造-岩浆增生作用表现为在单个AVRs的尺度上以及在二级段的尺度上作为一个整体。
SUMMARY A unifying model of oceanic crustal development at slow spreading rates is presented in which accretion follows a cyclic pattern of magmatic construction and tectonic destruction, controlled by along-axis variation in melt supply and coupled to along-axis variation in spreading rate and across-axis asymmetry in spreading. This study focuses on the Reykjanes Ridge, Mid-Atlantic Ridge south of Iceland, which is divided along its entire length into numerous axial volcanic ridges (AVR). Five adjacent AVRs have been analysed, located between 57 ◦ 30 � N and 58 ◦ 30 � N and south of any strong Iceland hotspot influence. The seabed morphology of each AVR is investigated using sidescan sonar data to determine relative age and eruptive history. Along-axis gravity profiles for each AVR are modelled relative to a seismically derived crustal reference model, to reveal the underlying crustal thickness and density structure. Correlating these models with seabed features, crustal structure, ridge segment morphology and relative ages, a model of cyclic ridge segmentation is developed in which accretion results in adjacent AVRs with a range of crustal features which, when viewed collectively, reveal that second-order segments on the Reykjanes Ridge have an along-axis length of ∼70 km and comprise several adjacent AVRs which, in turn, reflect the pattern of third-order segmentation. Tectono-magmatic accretion is shown to operate on the scale of individual AVRs, as well as on the scale of the second-order segment as a whole.
非常缓慢传播的西南印度洋脊的 TOBI 侧扫声纳图像：沿轴岩浆分布的证据，
DOI：
--
发表时间：
2002
期刊：
Earth Planet.Sci.Lett. 199
影响因子：
--
作者：
Sauter;D.;L.Parson;V.Mendel;C.Rommevaux-Jestin;O.Gomez;A.Briais;C.Mevel;K.Tamaki;FUJI scientific team
通讯作者：
FUJI scientific team