...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Tectonophysics: International Journal of Geotectonics and the Geology and Physics of the Interior of the Earth >Partial delamination of continental mantle lithosphere, uplift-related crust-mantle decoupling, volcanism and basin formation: a new model for the Pliocene-Quaternary evolution of the southern East-Carpathians, Romania
【24h】

Partial delamination of continental mantle lithosphere, uplift-related crust-mantle decoupling, volcanism and basin formation: a new model for the Pliocene-Quaternary evolution of the southern East-Carpathians, Romania

机译：大陆幔岩石圈的部分分层，与隆起有关的地幔幔解耦，火山作用和盆地形成：罗马尼亚东喀尔巴阡山脉的上新世-第四纪演化的新模型

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A geodynamic model is proposed for the Mid-Miocene to Quaternary evolution of the southern East-Carpathians in order to explain the relationships between shallow and deep geological phenomena that occurred synchronously during late-collision tectonics. In this area, an active volcanic zone cross-cuts since 2 My the suture between the overriding Tisza-Dacia and subducting European continental plates. Mafic calc-alkaline and alkaline magmas (south Harghita and Persani volcanoes) erupted contemporaneously. These magmas were supplied by partial melting of the mantle lithosphere of the subducting, and not of the overriding, plate. In an effort to decipher this geodynamically a-typical setting of magma generation, the spatial and temporal distribution of shallow and deep phenomena was successively examined in order to establish the degree of their interdependence. Our model indicates that intra-mantle delamination of the subducting European plate is the principal cause of a succession of events. It caused upwelling of the hot asthenosphere below a thinned continental lithosphere of the Carpathians, inducing the uplift of the lithosphere and its internal decoupling at the Moho level by isostatic and mostly thermal effects. During this uplift, the crust deformed flexurally whilst the mantle deformed in a ductile way. This triggered decompressional partial melting of the uppermost mantle lithosphere. Flexural deformation of the crust induced its fracturing, allowing for the rapid ascent of magmas to the surface, as well as reactivation of an older detachment horizon at the base of the Carpathian nappe stack above which the Brasov, Ciuc and Gheorghieni hinterland basins formed by extension and gravity spreading. The rapid subsidence of the Focsani foreland basin is controlled by the load exerted on the lithosphere by the delaminated mantle slab that is still attached to it. In this model, crust-mantle decoupling, magma genesis and volcanism, local near-surface hinterland extension are consequences of uplift, induced by asthenospheric upwelling triggered by intra-mantle delamination. This model enables to conceive that delamination-induced decoupling began to be efficient 9.4 My ago at the northern end of the East-Carpathians, when the mantle slab dipped westwards. Since then, intra-mantle delamination migrated laterally, normal to the slab strike, and follows the arcuate shape (NW --> SE --> SW) of the Carpathians. Nowadays, whereas the mantle slab is still actively foundering below the Vrancea seismic zone to the SE of the most recent volcanic area (South Harghita-Persani), a significant southwestward shift of the delamination process can be discerned. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 92]
机译：为了解释晚碰撞构造过程中同步发生的浅层和深层地质现象之间的关系，提出了一种用于东中喀尔巴阡山脉中新世中期至第四纪演化的动力学模型。在该区域，自2 My以来，活跃的火山带在贯穿的Tisza-Dacia与俯冲的欧洲大陆板块之间被缝合。基性岩浆碱性钙质岩浆和碱性岩浆（Harghita火山和Persani火山南部）同时爆发。这些岩浆是通过俯冲的地幔岩石圈部分熔融而不是上覆板块的熔融而提供的。为了解释岩浆生成的这种地球动力学的非典型环境，为了确定它们之间的相互依赖程度，先后研究了浅层和深层现象的时空分布。我们的模型表明，俯冲的欧洲板块的地幔内部分层是一系列事件的主要原因。它在喀尔巴阡山脉变薄的大陆岩石圈下引起了热流软流圈的上升，在等静压和主要是热效应的作用下，导致了岩石圈的隆升及其在莫霍面的内部解耦。在隆起过程中，地壳弯曲变形，而地幔以韧性方式变形。这触发了最上层地幔岩石圈的减压部分融化。地壳的挠曲变形导致其破裂，从而使岩浆迅速上升到地表，并重新激活了喀尔巴阡岩浆叠层底部的一个较旧的脱离层，在该层之上，布拉索夫，库克和格奥尔基耶尼腹地盆地通过伸展形成和重力传播。 Focsani前陆盆地的快速沉降受仍附着在其上的分层地幔平板施加在岩石圈上的载荷控制。在该模型中，地幔-壳层的脱钩，岩浆成因和火山作用，局部近地表腹地的伸展是由壳层内分层触发的软流圈上升引起的隆升的结果。这个模型使我们可以认为，分层引起的解耦开始是有效的。9.4我以前是在东喀尔巴阡山脉的北端，当地幔板向西倾斜时。从那时起，地幔内分层横向于板坯走向横向移动，并遵循喀尔巴阡山脉的弧形形状（NW-> SE-> SW）。如今，尽管地幔平板仍在Vrancea地震带下方一直活跃地向最近的火山区（南Harghita-Persani）的东南方向凹陷，但可以看出分层过程向西南方向移动了很大。 （C）2000 Elsevier Science B.V.保留所有权利。 [参考：92]

著录项

相似文献

  • 外文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号