Antarctic Peninsula Exhumation and Landscape Development Investigated by Low-temperature Detrital Thermochronometry

智力优势：研究人员建议利用磷灰石中的（U-Th）/He系统来研究南极中部半岛的折返历史、现今地形的发展和冰川侵蚀的模式。南极半岛自始新世和更新世以来一直被冰川化，气候变冷被假设为抑制而不是增强了冰川侵蚀。为了实现这些目标，PI将使用热计时记录，记录目前的冰川谷地貌形成的时间和方式。拟议中的研究面临的一个挑战是，与温带地区的更新世冰川景观不同，半岛被冰层覆盖，不可能直接对基岩表面进行采样。PI希望通过对半岛主要冰川接地线附近收集的冰川沉积物进行磷灰石（U-Th）/He和4 He/3 He测量，了解冰川山谷形成的时间和过程。了解南极半岛景观是如何形成的，对于辨别冰川侵蚀的机制如何在长时间尺度上运作，以及了解冰川如何调解气候变化和造山带物质平衡之间的相互作用非常重要。这项工作解决了南极地球科学中的一个基本问题，即如何推断在冰层覆盖和难以进入的景观上活跃的地质和地貌过程。与英国南极调查研究人员的拟议合作将建立一个国际合作。该项目的成果对其他领域具有辅助重要性，并解决了南极地球科学的根本挑战。

Intellectual Merit: The PIs propose to use the (U-Th)/He system in apatite to investigate the exhumation history, development of the present topography, and pattern of glacial erosion in the central Antarctic Peninsula. The Antarctic Peninsula has been glaciated since the Eocene and Pleistocene climate cooling is hypothesized to have suppressed, rather than enhanced, glacial erosion. To achieve these goals, the PIs will use a thermochronometric record of when and how the present glacial valley relief formed. A challenge to the proposed research is that, unlike Pleistocene glacial landscapes in temperate areas, the Peninsula is ice-covered and it is not possible to directly sample the bedrock surface. The PIs hope to learn about the timing and process of glacial valley formation through apatite (U-Th)/He and 4He/3He measurements on glacial sediment collected near the grounding lines of major glaciers draining the Peninsula. Learning how the Antarctic Peninsula landscape formed is important to discern how the mechanics of glacial erosion operate on long time scales, and to understand how glaciers mediate the interaction between climate change and orogenic mass balance. This work addresses a fundamental question in Antarctic earth science of how to infer geologic and geomorphic processes active on an ice-covered and inaccessible landscape.Broader impacts: This proposal will bring new researchers into the Antarctic research community. A proposed collaboration with British Antarctic Survey researchers will build an international collaboration. The outcomes of this project have ancillary importance to other fields and addresses fundamental challenges in Antarctic Earth Science.