西菲律宾海晚第四纪沉积作用和沉积环境演化

IOCAS-IR > 海洋环流与波动重点实验室

	西菲律宾海晚第四纪沉积作用和沉积环境演化
	石学法
学位类型	博士
	1992
学位授予单位	中国科学院海洋研究所
学位授予地点	中国科学院海洋研究所
学位专业	海洋地质学
摘要	本文通过对西菲律宾海区三个柱状沉积物钻孔（WP_1、WP_2和WP_(40)孔）的沉积学、矿物学和元素地球化学综合研究，重建了该区晚第四纪以来沉积作用和沉积环境的演化历史。在系统研究沉积物粒度特征、全岩矿物组合、碎屑矿物组合、粘土矿物组合、常量元素地球化学和微量元素地球特征的基础上，探讨了西菲律宾海区沉积物来源、沉积作用、沉积环境及古气候特征，结合背景分析，进行了演化分析。本区沉积物来源和沉积作用可区分为5种类型：（1）陆源碎屑沉积；（2）海洋生物沉积；（3）海底火山沉积；（4）海洋自生沉积；（5）浊流沉积。陆源碎屑沉积由风和河流两种营力搬运而来，一部分来自邻近的菲律宾岛屿，一部分来自北方的中国大陆。海底火山沉积的原岩为玄武岩。WP_1孔中，陆源碎屑沉积物质较多，WP_2和孔WP_(40)孔中，海底火山沉积占优势。海洋生物沉积和海洋自生沉积主要受海洋自身环境条件的影响。而陆源沉积、海底火山沉积和浊流沉积还与沉积区的大地构造位置有关。从时间演化上来讲，西菲律宾海区晚第四纪沉积由下部的未次冰期沉积和上部的全新世沉积组成。未次冰期沉积又可区分为亚间冰期沉积和冰期最盛期沉积。亚间冰期沉积位于每个孔的最下部，发育生物沉积作用和火山沉积作用，陆源碎屑沉积作用相对较弱。中部的冰期最盛期沉积表现为陆源碎屑沉积作用显著增强，火山沉积作用和生物沉积作用减弱，陆源沉积物大部分来源于北方的中国大陆，与冰期时的气候背景有关，这些沉积物系由强烈的季风携带而来。上部的全新世沉积，生物沉积又有所增强，WP_1孔陆源沉积作用和火山沉积作用都较弱。WP_2和WP_(40)孔火山沉积作用也有所减弱，但陆源沉积作用仍较强，其沉积物主要来源于菲律宾岛的风化产物。
其他摘要	The sedimentology, mineralogy and element geochemistry of three cores (Hole WP1, WP2 and WP40) have been studied, the late Quaternary sedimentation processes in the area and the evolution of the sedimentary environment are reconstructed in this thesis. First, based on the comprehensive studies of grain size alaysis, whole rock mineral associations, heavy mineral associations, claymineral associations, element geochemistry and trace element geochemistry, the author discusses the provenance of sediments, sedimentation processes, sedimentary environments and paleaoclimate, and conducts analysis on evolution combining background analysis. The provernance and sedimentation processes fall into five categories: (1) terrigeneous clastic sedimentation, (2) marine organic sedimentation, (3) volcanic sedimentation at the sea bottom, (4) authigenic sedimentation and (5) turbity sedimentation. Terrigeneous clastic sediments, either from the adjoining Philippine islands or from China Mainland, were transported by two kinds of agents:wind are rivers. Volcanic sedimentation at the sea bottom originated from basalt. In Hole WP1 terrigeneous clastic sediments dominates, and in Hole WP2 and Hole WP40 volcanic sediments. Marine organic sedimentation and authigenic sedimentation are controlled by the environmental factors while terrigeneous clastic sedimentation, volcanic sedimentation at the sea bottom and turbity sedimentation are related to geotectonic positions. Stratigraphically, the late Quarternary sediments in the western Philippine Sea area consists of the lower last glacial sediments and the upper Holocene sediments. The last glacial sediments could be divided into sub-interglacial sediments and glacial--maximum sediments. Sub-interglacial sediments occur at the bottom of each holes, and in their corresponding time spans marine organic sedimentation and volcanic sedimentation predominated over terrigeneous clastic sedimentation. In period represented by the middle glacial-maximum sediments terrigeneous clastic sedimentation was enhanced and marine organic sedimentation and volcanic sedimentation predominated over terrigeneous clastic sedimentation. In period represented by the middle glacial-maximu sediments terrigeneous clastic sedimentation was enhanced and marine organic sedimentation and volcanic sedimentation weakened. Most of the terrigeneous sediments came from the northern China Mainland, probably by strong monsoons. In the period represented by the upper Holocene sediments marine organic sedimentation was enhanced again. In Hole WP1 terrgeneous clastic sedimentation and volcanic sedimentation are weak, while in both Hole WP2 and Hole WP40 volcanic sedimentations are weak but the terrigeneous clastic sedimentations get stronger, most sediments coming from the weathering product on Philippine islands.
页数	131
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1159
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	石学法. 西菲律宾海晚第四纪沉积作用和沉积环境演化[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,1992.

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