CAJ | 학술논문

混杂岩是古增生楔存在的标志之一,一般由枕状玄武岩、灰岩、放射虫硅质岩、硅质页岩、砂岩等混乱无序组成.目前"大洋板块地层"(OPS)运用放射虫地层学方法对混乱的增生楔断片进行重建取得了良好效果,并清晰地展示了大洋板块俯冲和洋底物质连续增生的历史.在西藏仲巴地区填图过程中,结合放射虫年代学分析鉴定结果,以OPS重建的思路和理论作为指导,重建了仲巴地区混杂岩的大洋板块地层,并恢复了该区域特提斯洋在洋中脊大洋板块增生至消亡的岩石序列,自下而上分别为侏罗纪海山玄武岩、海山覆盖物侏罗系—白垩系碳酸盐岩、海山周围沉积的侏罗系—白垩系放射虫硅质岩和硅质页岩,以及海沟附近的白垩系陆源碎屑岩等,为特提斯洋大洋板块俯冲的方向、持续时间和古大地构造环境提供了信息.
혼잡암시고증생설존재적표지지일,일반유침상현무암、회암、방사충규질암、규질혈암、사암등혼란무서조성.목전"대양판괴지층"(OPS)운용방사충지층학방법대혼란적증생설단편진행중건취득료량호효과,병청석지전시료대양판괴부충화양저물질련속증생적역사.재서장중파지구전도과정중,결합방사충년대학분석감정결과,이OPS중건적사로화이론작위지도,중건료중파지구혼잡암적대양판괴지층,병회복료해구역특제사양재양중척대양판괴증생지소망적암석서렬,자하이상분별위주라기해산현무암、해산복개물주라계—백성계탄산염암、해산주위침적적주라계—백성계방사충규질암화규질혈암,이급해구부근적백성계륙원쇄설암등,위특제사양대양판괴부충적방향、지속시간화고대지구조배경제공료신식.
Mélange generally consists of such chaotic blocks as pillow lava, limestones, radiolarian cherts, siliceous shales and sand-stones, which tectonically contact with each other. Mélange serves as a piece of evidence of the accretionary prism (AP) related to the subduction zones. Recently, by using radiolarian biostratigraphy, the theory of ocean plate stratigraphy (OPS) is referred to as an ap-proach to the accretionary process of these blocks. In order to reconstruct the process of subduction and successive accretion of ocean floor material of Neo-tethys, the authors used the theory to mapping the accretionary prism related to the Yalung Zangbo suture zone in Zhongba area, southern Tibet. The OPS of AP in Zhongba area consists of Jurassic basalt of sea mountain, Jurassic-Creta-ceous reefs on the sea mountain, the pelagic sediments such as siliceous shales and radiolarian cherts and the Cretaceous terrigenous clasts close to the trough. This study provides new information on the direction, duration and the tectonic settings of the subduction of the Neo-tethys Ocean.