Dynamics and numerical modeling of deep-seated accretionary prisms in the Chilean Coastal Cordillera

目标：我们的提案侧重于智利沿海科迪勒拉的高压/低温岩石。这些代表了收敛边际的短期增长。智利中部保存下来的增生系统显示了超过100 Ma的循环质量流，而弧花岗岩类则显示了稳定的楔后区域。北纬34°S和南纬48°S的类似增生棱柱被俯冲侵蚀破坏。我们的目标是了解化石智利增生棱镜的形成，俯冲，挖掘和破坏历史的主要原因，并与伴随的岩浆弧有关。方法。我们将(1)测试当前的概念模型，并通过数值热力学2d建模获得pttd路径，并受到变形，热和掘出历史的约束；(2)通过碎屑锆石（U/Pb）和白云母（Ar/Ar）测年，建立智利中部被动-活动大陆边缘的早期时间标志，阐明被动-活动大陆边缘的演化；(3)与合作项目合作，研究34°S和48°S增生棱柱的不同破坏机制，提供岩石学和年代学支持；(4)通过整理智利基底的所有资料，完善构造变质模型。

Objectives: Our proposal focusses on HP/LT rocks along the Coastal Cordillera of Chile. These represent short periods of growth of the convergent margin. Preserved accretionary systems in central Chile reveal cyclic mass flow over ~ 100 Ma, whereas arc granitoids matk stable retrowedge areas. N of 34°S and S of 48°S similar accretionary prisms are destroyed by subduction erosion. Our goal is to understand the principal causes for the formation, subduction, exhumation and destruction histories of fossil Chilean accretionary prisms in relation to concomitant magmatic arcs. Methodology. We will (1) test current conceptual models and acqired PTtd-paths by numerical thermomechanical 2D-modeling with constraints from the deformational, thermal and exhumational histories; (2) elucidate the evolution of passive-to-active continental margins by establishing early time markers in central Chile via detrital zircon (U/Pb) and white mica (Ar/Ar) dating; (3) study the different mechanisms of destruction of accretionary prisms N of 34°S and S of 48°S in cooperation with partner projects providing petrological and geochronological support; (4) to refine tectono-metamorphic models by compiling all information about the Chilean basement.