九州-帕劳海脊南段及邻近海域典型海山形态特征及地质意义  

Morphological characteristics and geological significance of seamounts in the southern Kyushu-Palau Ridge areas

作　　者：刘佳 李攀峰[2] 邢磊[1] 胡邦琦[2] 杨慧良[2] 赵京涛 LIU Jia;LI Panfeng;XING Lei;HU Bangqi;YANG Huiliang;ZHAO Jingtao(College of Marine Geosciences,Ocean University of China,Qingdao 266100,China;Qingdao Institute of Marine Geology,China Geological Survey,Qingdao 266237,China)

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]中国地质调查局青岛海洋地质研究所,青岛266237

出　　处：《海洋地质与第四纪地质》2024年第4期65-77,共13页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金面上项目“菲律宾海盆底层水体性质对中更新世气候转型的响应机制”(41976192);中国地质调查局项目(DD20191010,DD20191003,DD20230647);自然资源部海底科学重点实验室开放基金“多波束后向散射强度对九州-帕劳海脊多金属结核分布的响应”(KLSG2103)。

摘　　要：对海山形态特征的定量分析与讨论,有助于理解海山的形成与演化,从而进一步了解与海山地貌形态有关的动力作用。基于九州-帕劳海脊南段及邻近海域的高分辨率海底地形和浅地层剖面资料,利用统计学、频谱分析及层序地层学等方法,查明了研究区40座海山的形态特征,并对海山的演化过程进行了分析推测,同时指出了海山对底流沉积动力的影响。结果表明,研究区海山平均高度为1374 m,平均体积为100 km3,宽高比为0.21±0.09,平坦度为0.16±0.18;在中央海盆裂谷北侧和九州-帕劳海脊南段海山高度与底面半径具有较好的线性关系,而在中央海盆裂谷南侧相关性较差;中央海盆裂谷南侧海山的宽高比明显大于北侧,可能是由复杂的应力背景和构造机制等因素所导致。总结火山演化的4种生长模型,分析认为研究区海山的形态演化与山顶高度和基底直径成比例增加的火山生长模型基本类似,可能是由于火山间断喷发导致海山顶部与侧翼同时成比例发育。The quantitative morphology study of volcanic seamount helps to understand the seamount evolution and intrinsic relationship between seamount morphology and geodynamics.High-resolution seabed topography data of 40 volcanic seamounts in the southern Kyushu-Palau Ridge and adjacent areas were used to analyze statistically the seamount morphology and the influence on sedimentation dynamics of bottom flow by spectral and sequence stratigraphy analyses.Results show that the average height of seamounts in the study area is 1374 m,the average volume is 100 km3,the aspect ratio is 0.21±0.09,and the flatness is 0.16±0.18.The height of seamounts in the northern Central Basin Rift and the southern Kyushu-Palau Ridge show a good linear correlation with the bottom radius,while the correlation between seamounts in the southern Central Basin Rift is poor.The aspect ratio of seamounts in the southern Central Basin Rift is significantly greater than that in the northern Central Basin rift due probably to complicated stress fields under regional tectonic frames.By summarizing four volcanic evolution models,we found that the seamounts in the study area fit the model that they grow with proportional increase in summit height and base diameter,which could be explained by intermittent volcanic eruptions leading to proportional development on the top and flanks.

关 键 词：成因演化 沉积动力 海山 九州-帕劳海脊 

分 类 号：P736.21[天文地球—海洋地质]