Structural Characteristics of the Andaman Forearc Inferred from Interpretation of Multichannel Seismic Reflection Data

作     者：Anitha GOLI Dhananjai K.PANDEY 

作者机构：National Centre for Antarctic and Ocean Research 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2014年第88卷第4期

页      面：1145-1156页

核心收录：

学科分类：0820[工学-石油与天然气工程] 070704[理学-海洋地质] 0709[理学-地质学] 0819[工学-矿业工程] 07[理学] 0707[理学-海洋科学] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 082002[工学-油气田开发工程] 

主　　题：Structural geology tectonics Tertiary hydrocarbon potential upwarp Andaman Indian Ocean 

摘      要：The Andaman Forearc Basin （AFB） is asymmetric in configuration and filled with a-6 km-thick pile of Neogene to Recent sediments （-4 s in two-way travel time： TWT） with distinct zonation. It shows gradual thinning up to -3 km （0.8 s in TWT） towards the eastern end with a seabed gradient of 1：30. Thick deformed sediments -2 s （TWT） of the Outerarc are associated with intense faulting and occasional folding caused by recent tectonics. Development of a series of faults within the upwarped sedimentary column of Oligocene top to Recent is observed with a rotated fault block. These features are manifestations of Recent igneous intrusion, and reveal the presence of a mild N-S compressional regime. Its effect on the AFB resulted in further uplift of sediments, which can now be seen as the Invisible Bank. Forward gravity modelling supporting our seismic interpretation reveals that it is associated with igneous intrusion from the Moho （-9 km depth）, and also suggests that continental crust underlies the AFB. Strong Bottom Simulating Reflector （BSR）-like features in the Miocene sediments of Outerarc and Forearc basin at a depth of 0.6 s below the seabed suggest the inferred probable occurrence of gas hydrates in the AFB.