Geodynamics of oceanic plateau and plume head accretion and their role in Phanerozoic orogenic syste

来源 :Geoscience Frontiers | 被引量 : 0次 | 上传用户:gg106419
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
We present three 3D numerical models of deep subduction where buoyant material from an oceanic plateau and a plume interact with the overriding plate to assess the influence on subduction dynamics,trench geometry,and mechanisms for plateau accretion and continental growth.Transient instabilities of the convergent margin are produced,resulting in:contorted trench geometry;trench migration parallel with the plate margin;folding of the subducting slab and orocline development at the convergent margin;and transfer of the plateau to the overriding plate.The presence of plume material beneath the oceanic plateau causes flat subduction above the plume,resulting in a “bowed” shaped subducting slab.In plateau-only models,plateau accretion at the edge of the overriding plate results in trench migration around the edge of the plateau before subduction is re-established directly behind the trailing edge of the plateau.The plateau shortens and some plateau material subducts.The presence of buoyant plume material beneath the oceanic plateau has a profound influence on the behaviour of the convergent margin.In the plateau + plume model,plateau accretion causes rapid trench advance.Plate convergence is accommodated by shearing at the base of the plateau and shortening in the overriding plate.The trench migrates around the edge of the plateau and subduction is re-established well behind the trailing edge of the plateau,effectively embedding the plateau into the overriding plate.A slab window forms beneath the accreted plateau and plume material is transferred from the subducting plate to the overriding plate through the window.In all of the models,the subduction zone maintains a relatively stable configuration away from the buoyancy anomalies within the downgoing plate.The models provide a dynamic context for plateau and plume accretion in Phanerozoic accretionary orogenic systems such as the East China Orogen and the Central Asian Orogen(Altiads),which are characterised by accreted ophiolite complexes with diverse geochemical affinities,and a protracted evolution of accretion of exotic terranes including oceanic plateau and terranes with plume origins. We present three 3D numerical models of deep subduction where buoyant material from an oceanic plateau and a plume interact with the overriding plate to assess the influence on subduction dynamics, trench geometry, and mechanisms for plateau accretion and continental growth. Transitional instabilities of the convergent margin are produced, resulting in: resulting in trench geometry; trench migration parallel with the plate margin; folding of the subducting slab and orocline development at the convergent margin; and transfer of the plateau to the overriding plate. causes flat subduction above the plume, resulting in a “bowed” shaped subducting slab.In plateau-only models, plateau accretion at the edge of the overriding plate results in trench migration around the edge of the plateau before subduction is re-established directly behind the trailing edge of the plateau. The plateau shortens and some plateau material subducts. The presence of buoyan t plume material beneath the oceanic plateau has a profound influence on the behavior of the convergent margin. the plateau + plume model, plateau accretion causes rapid trench advance. Plate convergence is accommodated by shearing at the base of the plateau and shortening in the overriding plate. the trench migrates around the edge of the plateau and subduction is re-established well behind the trailing edge of the plateau, effectively embedding the plateau into the overriding plate. A slab window forms beneath the accreted plateau and plume material is transferred from the subducting plate to the overriding plate through the window. all of the models, the subduction zone maintains a relatively stable configuration away from the buoyancy anomalies within the downgoing plate. the models provide a dynamic context for plateau and plume accretion in Phanerozoic accretionary orogenic systems such as the East China Orogen and the Central Asian Orogen (Altiads), which are characterised by accreted ophiolite complexes with diverse geochemical affinities, and a protracted evolution of accretion of exotic terranes including oceanic plateau and terranes with plume origins.
其他文献
在我国,随着旅游市场的繁荣,旅行社作为旅游行业的龙头得到了突飞猛进的发展。随着旅游者消费能力的提升,现有旅行社的服务质量已经不能满足旅游者的需求,服务质量控制方式体
中组部副部长赵宗鼐在6月16日《组织人事报》上发表文章强调,建立现代企业制度,企业党建工作只能加强,不能刚弱。他说,企业是工人阶级最集中的地方,企业党的建设是基层党组
药品是一类用于预防、治疗、诊断人体疾病,有目的地调节人体生理机能并规定有适应症、用法和用量的物质,药品作为特殊的商品,它与消费者的健康和生命密切相关。 药品生产企业
我国的中小企业数量多,对国民经济的发展起着不可替代的推动作用。我国加入WTO后,中小企业面临着巨大的机遇和挑战。21世纪的竞争主要是人才的竞争,中小企业要想在激烈的竞争中
本文叙述矿堆和浸出反应槽生物氧化金属硫化矿石和精矿的微生物学基础 ,并根据该类微生物的催化反应及培养要求 ,鉴别和叙述了主要的微生物体。还从溶液化学、温度和矿物沉淀
动画作品和一般演员所出演的影视作品相比较来说有他自己不同的特点.比如动画作品的自由度更高,也容易被普通的观众所接受.在动画制作当中,分镜头脚本始终贯穿于整个过程,而
随着中国经济的高速发展和人民币的迅速升值,人民基本物质生活水平的大幅度提升,城市居民的人均可支配收入增长,中国旅游市场快速发展。中国互联网旅游行业近年来蓬勃发展,旅游网
关于项目式学习,巴克教育研究所(Buck Institute for Education)对标准化项目式学习的定义具有代表性,即在一段时间内,督促学生对真实的、复杂的问题进行探究,并且从中获得知
期刊
这是属于金陵晚报人风华正茂的20岁生日。同样,她也属于每一位金陵晚报读者。2012年,金陵晚报20周年盛典拉开帷幕,为自己庆生、更为这座城市献礼。8月,“新金陵48景”评选启
当下社会广告已经成为一种宣传媒介,然而广告宣传的形式也是多种多样的,其中较为普遍的要数平面广告了,它在人们的实际生活中所起到的作用是至关重要的,针对平面广告的设计来