High-resolution Remotely Operated Vehicle (ROV) mapping of a slow-spreading ridge: Mid-Atlantic Ridge 45°N
High-resolution Remotely Operated Vehicle (ROV) mapping of a slow-spreading ridge: Mid-Atlantic Ridge 45°N
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缓慢扩张的山脊的高分辨率遥控潜水器 (ROV) 测绘：大西洋中脊 45°N
DOI：
10.1002/ggge.20082
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Yeo I
中科院分区：
文献类型：
--
作者：
Yeo I
摘要：在大多数扩张缓慢的洋中脊上发现了轴向火山脊（AVRs），并被认为是那里火山活动的主要场所。在这项研究中，我们在45°N的大西洋中脊上绘制了一个典型的、定义明确的AVR的高分辨率地图。AVR的特点是“丘陵地形”，由典型的丘陵组成，有枕状或细长的枕状侧翼，有枕状或片状的熔岩流峰顶，通常在最高点上有小干草堆。AVR周围有几个“平坦的海底”区域，由片状和片状熔岩流组成。这些区域之间的空间和形态差异表明在AVR上和AVR外有不同的喷发过程。尽管水平位移最大的火山裂缝位于山脊顶部和平坦的海底，但火山裂缝在AVR周围和上面都可以找到。成团的裂缝可能代表火山的通风口。对沉积物覆盖范围的极其详细的比较和对AVR周围接触关系的考察表明，许多平坦海底地区的年龄与AVR的丘状地形相似或更年轻。此外，所有被调查的熔岩都有相似程度的沉积物覆盖，这表明AVR要么是在与平坦海底相同的50 ka时间框架内建造的，要么是重新出现的。
AbstractAxial volcanic ridges (AVRs) are found on most slow‐spreading mid‐ocean ridges and are thought to be the main locus of volcanism there. In this study we present high‐resolution mapping of a typical, well‐defined AVR on the Mid‐Atlantic Ridge at 45°N. The AVR is characterized by “hummocky terrain,” composed typically of hummocks with pillowed or elongate pillowed flanks with pillowed or lobate lava flow summits, often with small haystacks sitting on their highest points. The AVR is surrounded by several areas of “flat seafloor,” composed of lobate and sheet lava flows. The spatial and morphological differences between these areas indicate different eruption processes operating on and off the AVR. Volcanic fissures are found all around and on the AVR, although those with the greatest horizontal displacement are found on the ridge crest and flat seafloor. Clusters of fissures may represent volcanic vents. Extremely detailed comparisons of sediment coverage and examination of contact relations around the AVR suggest that many of the areas of flat seafloor are of a similar age or younger than the hummocky terrain of the AVR. Additionally, all the lavas surveyed have similar degrees of sediment cover, suggesting that the AVR was either built or resurfaced in the same 50 ka time frame as the flat seafloor.