裂后岩浆活动中岩床复合体的特征:以南海北部和南极西罗斯海地区为例

发布时间：2018-01-27 22:28

本文关键词： 南海北部西罗斯海地震识别岩床复合体　出处：《大地构造与成矿学》2017年06期 　论文类型：期刊论文

【摘要】：由于蕴含着潜在的油气勘探和资源储藏信息,岩床复合体在全球范围内被广泛研究。本文基于南海北部三维地震资料以及南极罗斯海地区二维多道地震资料,对岩床复合体的形态特征及分布进行分析,对两个地区岩床复合体的形成时间进行判断,阐述岩床复合体的侵位机制。研究发现,岩床复合体代表性产状除了菱形、碟形及复合型外,还存在沿着层位平行侵入的板状,推测它可能是夭折了的岩床侵入体,以及由几个小型岩床堆叠而成的透镜状岩床复合体。分布上,南海北部岩床主要发育于珠江口盆地白云凹陷三维工区西部,东部只零星可见;南极西罗斯海岩床主要发育于西北角的阿黛尔盆地内。根据岩床上覆的强制褶皱结合区域构造背景,推测南海北部岩床复合体的形成时间为早中新世(15.5 Ma),海底扩张结束之时。残余岩浆将盆地内裂谷时期形成的断层作为岩浆运移的通道,并最终在断层终点处即下中新统近海相砂泥岩地层中实现侵位。南极西罗斯海岩床复合体的形成时间则非常晚,不早于5.5 Ma。该区这期岩浆活动可能与构造作用无关,而是受到冰川消融的影响。研究发现岩床复合体内部的岩床个体互相供给,即深部的大岩床为上覆浅层的小岩床提供岩浆供给,并且互相组合,形成大的岩床复合体。然而,每个岩床复合体则可能由不同的岩浆供给发育而成。
[Abstract]:Because of the potential oil and gas exploration and resource storage information, the rock bed complex has been widely studied in the world. This paper is based on the three-dimensional seismic data of the northern South China Sea and the two-dimensional multi-channel seismic data of the Ross Sea area, Antarctica. The characteristics and distribution of rock bed complex are analyzed, the formation time of rock bed complex in two areas is judged, and the emplacement mechanism of rock bed complex is expounded. In addition to the rhombic, dish and composite types, the typical occurrence of the rock bed complex is also a plate-like intrusion parallel to the horizon, which suggests that it may be a dead intrusive body of the rock bed. And the lenticular rock bed complex composed of several small rock beds. The rock beds in the northern part of the South China Sea are mainly developed in the western part of Baiyun sag in the Pearl River mouth basin, and only sporadically in the eastern part of the South China Sea. The west Ross sea rock bed in Antarctica is mainly developed in the Adele basin in the northwest corner of Antarctica. According to the regional tectonic setting of forced fold combination on the rock bed. It is inferred that the formation time of the rock bed complex in the northern part of the South China Sea is 15.5 Mag in the early Miocene and at the end of the undersea expansion. The residual magma takes the faults formed during the rift period in the basin as the passage of magma migration. Finally, emplacement was realized at the end point of the fault, that is, the Lower Miocene offshore facies sand and mudstone strata. The formation time of the West Ross Sea complex in Antarctica was very late. No earlier than 5.5 Ma. the magmatic activity in this area may not be related to tectonism but influenced by the melting of glaciers. It is found that the individual beds within the rock bed complex supply each other. In other words, the deep large rock beds provide magma supply to the small beds of the overlying shallow strata, and combine with each other to form a large rock bed complex. However, each rock bed complex may be developed from different magma supplies.
【作者单位】：国家海洋局第二海洋研究所;国家海洋局海底科学重点实验室;中国科学院深海科学与工程研究所;
【基金】：“全球变化与海气相互作用”专项“东亚大陆边缘现代地质过程与致灾机理”(GASI-GEOGE-05) 国家海洋局第二海洋研究所专项资金项目“由罗斯海岩浆活动分布研究西南极裂谷系统特征”(14260-10) 中国博士后科学基金“南极西罗斯海新生代岩浆活动时空分布及其指示意义”(17090041) 科技部重大仪器专项“海洋-航空重力仪研制”(2011YQ12004505) 极地专项“南北极环境综合考察与评估专项”(CHINARE2017-01-03;CHINARE2017-04-01) 国家自然科学基金“南极罗斯海陆架盆地幕式张裂构造和过程的时空变化研究”(41576069)联合资助
【分类号】：P618.13;P736
【正文快照】： 0引言含油气盆地中发育着对油气勘探和资源储藏都非常重要的岩床复合体。尽管可能没有直接的经济效益,由于它们影响地震成像及深部目标储层的钻探(Planke et al.,2000;Aresher et al.,2005),岩床复合体还是引起了相当大的关注。全球范围内沉积盆地中的岩床复合体已经被广泛研

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