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

在大陆上，地势较低的高海拔大地表是很常见的。这种抬升通过影响排水网络和沉积物供应对地质记录产生重大影响，通过改变大气环流对气候产生重大影响，并对生物地理和生物群产生重大影响。地球动力学方面的研究表明，这种隆起相当于地幔动力学的一个有力标志。因此，它们提供了一种方法来区分关于大陆岩石圈和更深的地幔如何通过导致大陆内部隆起和质量传递的过程相互作用的假设。蒙古中部的汉盖巨蛋为研究这些过程提供了一个极好的、可接近的实验室，并确定地幔上升流、基性底沉积、岩石圈沉没或羽流活动在其隆起中的重要作用程度。这个为期五年的项目提议将HangayDome作为这样一个实验室，以协调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的历史。该项目将涉及使用宽频地震学、玄武岩和捕虏体岩石学和地球化学、40Ar/ 39argeo年代学、稳定同位素和泡状玄武岩古高程、地形学和10be地质年代学、不同鱼类种群的分子遗传学、U-Th/He和4he /3He热年代学进行观测和测量。汉盖巨蛋？在过去的30万年里，大量的玄武岩熔岩在不同的海拔范围内喷发，这将是整合所有这些数据的关键。玄武岩的年代测定将使玄武岩成因的岩石学数据和汉盖穹幔的性质与使用熔岩作为记录景观演化和地表隆起历史的时间标记的研究联系起来。

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.