摘要
西湖凹陷花港组是研究区重要的储层之一,其物源一直是争论的焦点。应用砂岩碎屑组分特征,重矿物分析并结合砂地比等值线图精细描绘物源分支,从不同角度、不同层次对西湖凹陷花港组物源体系进行了精细研究。结果表明,西湖凹陷花港组物源主要来自凹陷的西部边缘,东部钓鱼岛隆褶带影响较小,具体分为3大分支:西部的海礁隆起为近物源、西北部虎皮礁凸起和东部钓鱼岛隆褶带物源的结合影响凹陷北部地区、西南部的渔山隆起为凹陷的中南部地区提供物源。通过对岩屑类型、长石特征、石英颗粒和重矿物的微观特征和稀土元素等特征的分析,推测出凹陷周边岩体性质,花港组的母岩主要是岩浆岩,其次为变质岩,沉积岩少见。变质岩主要发育在海礁隆起的中部,影响西部的平湖地区,沉积岩仅在钓鱼岛隆褶带北部地区少量发育。
The Huagang Formation in Xihu sag is an important reservoir,of which the provenance has been the focus of debate at all times.The source branches are finely pictured according to the characteristics of debris composition and heavy mineral analysis combined with sand percent distribution map.The results show that the Huagang Formation provenance mainly originated from the western edge of Xihu sag and a little from the eastern Diaoyu islands fold belt.The provenance is specific divided into three branches： the western Haijiao uplift source,north-west Hupijiao uplift and east of the Diaoyu islands fold belt source which compensatively affect north area,and south-west Yushan uplift source affecting the central and southern area.The natures of the rocks around depression are speculated by analyzing debris type,feldspar features,microscopic characteristics of quartz grains and heavy minerals,rare earth elements and so on.The rocks around the Xihu sag are mainly magmatic rocks,secondly metamorphic rocks,and rarely sedimentary rocks.Metamorphic rocks are developed in the middle of Haijiao uplift affecting western Pinghu area.Only a few Sedimentary rocks exit in the northern part of the Diaoyu islands fold belt.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2011年第2期315-323,共9页
Natural Gas Geoscience
基金
南海深水盆地油气资源形成与分布基础性研究(编号:2009CB219400)
国土资源部全国油气资源战略调查与评价项目“南海北部陆坡深水海域油气资源战略调查与评价”(编号:XQ-2004-05)
国家科技重大专项海洋深水区油气勘探关键技术(编号:2008ZX05000-025)
中国科学院“西部之光”联合学者项目联合资助
关键词
物源分析
稀土元素配分模式
重矿物组合
花港组
西湖凹陷
Provenance analysis
REE distribution pattern
Heavy mineral assemblage
Huagang Formation
Xihu sag.
