Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340-猫眼课题宝

DOI：

10.1002/2014gc005652

发表时间：

2015-02

期刊：

Geochemistry

影响因子：

3.7

通讯作者：

中科院分区：

地球科学3区

文献类型：

作者：

A. Friant;O. Ishizuka;G. Boudon;M. Palmer;P. Talling;B. Villemant;T. Adachi;M. Aljahdali;C. Breitkreuz;M. Brunet;B. Caron;M. Coussens;C. Deplus;D. Endo;N. Feuillet;A. Fraas;A. Fujinawa;M. Hart;R. Hatfield;M. Hornbach;M. Jutzeler;K. Kataoka;J. Komorowski;E. Lebas;S. Lafuerza;F. Maeno;M. Manga;M. Martínez-Colón;M. McCanta;S. Morgan;T. Saito;A. Slagle;S. Sparks;A. Stinton;N. Stroncik;K. Subramanyam;Y. Tamura;J. Trofimovs;B. Voight;D. Wall-Palmer;Fei Wang;S. Watt

2012年3月至4月，印度洋钻探项目第340次考察队在小安的列斯群岛蒙特塞拉特、马提尼克和多米尼克近海成功钻探了一系列地点。这些是火山岛周围聚集的少数几个钻探地点之一，也是第一次对大型和可能的海啸火山岛弧滑坡沉积物进行科学钻探。这些岩心为以前关于这些矿床的成分和起源的假设提供了证据和检验。穿透滑坡沉积物的U1394、U1399和U1400站点仅回收了海底沉积物，主要包括浊积岩和半远洋沉积物，缺乏碎屑雪崩沉积物。这支持了以下概念：i/火山碎屑雪崩倾向于在坡折处停止，ii/火山物质的初始就位可能引发预先存在的低梯度海底沉积物的广泛和大量破坏。马提尼克近海（U1399和1400），滑坡沉积物由倾斜或微断层的平行地层块组成，有时被均匀沉积物间隔（强烈剪切）隔开，而蒙特塞拉特近海的U1394现场穿透了一个平坦的完整地层块。产生这些大规模海底沉积物破坏的最可能机制似乎是火山碎屑雪崩加载和切割的近端区域滑脱的传播。这些结果对海啸产生的强度有影响。在某些条件下，主要由海底沉积物组成的火山岛滑坡沉积物往往会形成比快速进入水中的等量陆上块体丰富的物质流更小的海啸。远征340还成功地钻探了一些地点，以获取火山喷发落尘层与海洋沉积物夹层的未受干扰的记录，这些记录提供了一个出色的高分辨率数据集，用于分析火山喷发和滑坡周期，提高对岩浆演化以及近海沉积过程的理解。

IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island‐arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of preexisting low‐gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or microfaulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat‐lying block of intact strata. The most likely mechanism for generating these large‐scale seafloor sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits composed of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block‐rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high‐resolution data set to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes.

Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340

文献摘要

被引文献

相似文献