嘉偕平顶山群重磁异常及其构造和沉积特征  

GRAVITY AND MAGNETIC ANOMALIES OF JIAXIE GUYOTS AND THEIR STRUCTURAL AND SEDIMENTARY CHARACTERISTICS

作　　者：杨永[1] 何高文[1] 刘方兰[1] 涂广红[1] 韦振权[1] 邓希光[1] 姚会强[1] 刘永刚[1] 

机构地区：[1]国土资源部海底矿产资源重点实验室,中国地质调查局广州海洋地质调查局,广州510075

出　　处：《海洋地质与第四纪地质》2016年第1期107-113,共7页Marine Geology & Quaternary Geology

基　　金：国际海域资源调查与开发“十二五”专项课题(DY125-13-R-05);前沿性课题(DY125-22-QY-07);国土资源部海底矿产资源重点实验室基金课题(KLMMR-2013-A-03)

摘　　要：对嘉偕平顶山群重力数据进行了垂向导数处理,磁力数据进行了解析信号处理。重力垂向导数异常显示海山斜坡至坡底发育几个局部重力低异常,反映了此处存在低密度的沉积;磁解析信号异常显示海山斜坡山脊和山顶存在局部磁力高异常,反映了此处存在高磁性体。综合分析后认为重力垂向导数低异常可能是重力滑塌作用引起的碎屑流沉积的反映,磁解析信号高异常可能与侧翼裂谷带引起的岩墙侵入和火山活动相关,进而形成了斜坡山脊和山顶局部隆起。海山重力滑塌作用引起的碎屑流沉积多位于侧翼裂谷带附近区域,这可能是侧翼裂谷带处易发生岩墙侵入和火山活动,在此阵发性因素诱导下,易发生较大规模的重力滑塌。Gravity data of the Jiaxie Guyots are processed with vertical derivative（VDR）method and magnetic data processed with analytical signal amplitude（ASM）method.VDR gravity data show several low anomalies in some areas of the slope and foot of the guyots,indicating low-density sediments.ASM magnetic data,however,show high anomalies in some areas of the guyots slope and top,indicating highly magnetized bodies.After the comprehensive analysis of the data,we come to the conclusion that the low VDR gravity anomalies probably suggest the debris flow deposits caused by gravity slide,and the high ASM magnetic anomalies probably indicate dyke intrusion and volcanic activities caused by flank rifting which also leads to the formation of ridges on guyots slope and uplift in some areas of the guyots top.Phenomenon that debris flow sediments are mainly distributed around flank rift zones suggests that dyke intrusion and volcanic activities in flank rift zones are probably the reason of large-scale gravity slides.

关 键 词：重力垂向导数 磁解析信号 侧翼裂谷带 重力滑塌 嘉偕平顶山群 

分 类 号：P736.1[天文地球—海洋地质]