Ups and downs on spreading flanks of ocean-island volcanoes: Evidence from Mauna Loa and Kīlauea
Ups and downs on spreading flanks of ocean-island volcanoes: Evidence from Mauna Loa and Kīlauea
复制标题
海岛火山两侧的起伏：莫纳罗亚火山和基拉韦厄火山的证据
DOI：
10.1130/g19745.1
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
H. Yokose
中科院分区：
文献类型：
--
作者：
P. Lipman;B. Eakins;H. Yokose
人们普遍认为，夏威夷火山的海底侧翼沉积物主要是由重力驱动的火山扩张和伴随的滑坡形成的。潜水器的观测表明，莫纳罗亚火山和克鲁克劳厄火山两侧中部深处的突出沉积物是由附近浅层海底和同一大厦的陆上侧翼的山体滑坡产生的火山碎屑碎屑组成的。冒纳罗亚山成熟的陆生拉玄岩盾上的大块滑动角砾岩位于南科纳台阶的前缘崖下。相比之下，粗粒火山碎屑沉积物主要来自海底喷发的古Kīlauea的盾状前碱性玄武岩和过渡玄武岩。两个中坡台阶记录了相同的边坡破坏的一般过程，随后在火山持续扩张期间适度压缩，尽管它们记录了大厦生长的不同阶段的发育。潜水结果表明，科纳盆地北端的火山碎屑岩，被其他人解释为来自古老火山的远端沉积物，这些沉积物被遥远的逆冲运动剥离、隆起并吸积到岛上，或者是沉积在南科纳盆地后面的一个很大程度上连贯的地层组合。
Submarine-flank deposits of Hawaiian volcanoes are widely recognized to have formed largely by gravitationally driven volcano spreading and associated landsliding. Observations from submersibles show that prominent benches at middepths on flanks of Mauna Loa and Kīlauea consist of volcaniclastic debris derived by landsliding from nearby shallow submarine and subaerial flanks of the same edifice. Massive slide breccias from the mature subaerial tholeiitic shield of Mauna Loa underlie the frontal scarp of its South Kona bench. In contrast, coarse volcaniclastic sediments derived largely from submarine-erupted preshield alkalic and transitional basalts of ancestral Kīlauea underlie its Hilina bench. Both midslope benches record the same general processes of slope failure, followed by modest compression during continued volcano spreading, even though they record development during different stages of edifice growth. The dive results suggest that volcaniclastic rocks at the north end of the Kona bench, interpreted by others as distal sediments from older volcanoes that were offscraped, uplifted, and accreted to the island by far-traveled thrusts, alternatively are a largely coherent stratigraphic assemblage deposited in a basin behind the South Kona bench.