Collaborative Research: Intracontinental Deformation and Surface Uplift: Geodynamic Evolution of the Hangay Dome, Mongolia, Central Asia

在大陆上，相对高海拔的低起伏地表是很常见的。这种隆起通过影响排水网络和沉积物供应而对地质记录产生重大影响，通过改变大气环流而对气候产生重大影响，并对地理学和生物区系产生重大影响。地球动力学的研究表明，这样的隆起相当于地幔动力学的一个明显特征。因此，他们提供了一种手段来区分大陆岩石圈和更深的地幔如何相互作用的过程，导致隆起和质量转移incontinental的假说。蒙古中部的Hangay Dome为研究这些过程和确定地幔上涌、基性岩底侵、岩石圈下沉或地幔柱活动在其隆升中的重要作用程度提供了一个极好的和可访问的实验室。这个为期五年的项目建议利用HangayDome作为这样一个实验室，以协调对岩石圈和岩石圈下地幔的结构和状态以及地表隆起和景观演化历史的研究。该项目将涉及利用宽频带地震学、玄武岩和捕虏体岩石学和地球化学、40 Ar/39 Ar地质年代学、稳定同位素和泡状玄武岩古测高学、地貌学和10 Be地质年代学、不同鱼类种群的分子遗传学以及U-Th/He和4 He/3 He热年代学进行的观测和测量。 汉盖圆顶？在过去的30 Ma中，玄武岩熔岩在大范围的海拔上爆发，其广泛的暴露将是所有这些数据整合的关键。 玄武岩的定年将使岩石学数据对玄武岩成因和性质的悬挂圆顶地幔与研究，使用熔岩作为时间标记，记录景观演变和历史的表面隆起的联系。

Large relatively high-elevation surfaces with low relief are common onthe continents. Such uplifts have a significant impact on the geological record by influencing drainage networks and sediment supply, on climate by modifyingatmospheric circulation, and on biogeography and the biota. Work in geodynamics hasshown that such uplifts amount to a telling signature of mantle dynamics. Thus, theyprovide a means to discriminate among hypotheses about how the continental lithosphereand the deeper mantle interact through processes that result in uplift and mass transfer incontinental interiors. The Hangay Dome in central Mongolia provides an excellent andaccessible laboratory to investigate these processes and determine the degree to whichmantle upwelling, mafic underplating, lithospheric foundering or plume activity havebeen important agents in its uplift. This five-year project proposes to use the HangayDome as such a laboratory to coordinate studies of both the structure and state of thelithosphere and the sublithospheric mantle as well as the history of surface uplift andlandscape evolution. The project will involve observations and measurements made usingbroadband seismology, basalt and xenolith petrology and geochemistry, 40Ar/39Argeochronology, stable-isotope and vesicular-basalt paleoaltimetry, geomorphology and10Be geochronology, molecular genetics of divergent fish populations, and U-Th/He and4He/3He thermochronology. The Hangay Dome?s widespread exposures of basaltic lavas,which were erupted over the past 30 Ma across a broad range of elevations, will be key tothe integration of all these data. Dating of the basalts will enable linkage of petrologic databearing on basalt genesis and the nature of the Hangay-Dome mantle with studies thatuse the lavas as time markers for documenting landscape evolution and the history ofsurface uplift.