RUI:Carbonate Platform and Reef Development in the AlexanderTerrane of Southeastern AK

早至晚志留世Heceta组灰岩记录了该区最早的广泛碳酸盐沉积，是弧内浅水台地发育的最早基础。亚历山大岛弧内浅层至深层潮下沉积物保存完好，与其他岛弧内许多海洋沉积物保存不佳形成鲜明对比。因此，这些灰岩为构造活动区碳酸盐沉积的样式、过程和水深测量提供了重要的见解。虽然以前被描述为浅海成因，但赫塔组灰岩可分为浅水台地相、台地边缘相和斜坡相。更新支持将使PI能够从事与以下相关的主题：(1)亚历山大弧内的礁沉积动力学和碳酸盐台地发育；(2)弧内叠层石分布的物理和生物控制；(3)区域生物地理相关性。拟议的研究将包括为期两年的实地工作和实验室分析，并将产生一个构造框架内碳酸盐台地和珊瑚礁演化的模型。研究结果将有助于进一步认识不同构造背景下志留系礁体的演化与衰亡、显生宙叠层石发育的影响因素以及亚历山大地体的古地理特征。

Early to Late Silurian limestones from the Heceta Formation record the earliest occurrence of widespread carbonate deposition in the region and represent the earliest foundation for shallow water platform development within the arc. The excellent preservation of shallow to deep subtidal deposits within the Alexander arc contrasts with the poor preservation of many marine sediments that originated within other island arcs. Hence, these limestones provide important insights into the styles, processes and bathymetry of carbonate deposition in tectonically active areas. Although previously described as having a shallow marine origin, the limestones from the Heceta Formation can be differentiated into shallow water platform, platform margin, and slope facies. Renewal support will enable PI to pursue topics that relate to: (1) the dynamics of reef sedimentation and carbonate platform development within the Alexander arc; (2) physical and biologic controls on stromatolite distribution within the arc; and (3) regional biogeographic correlations. The proposed research will involve field work and laboratory analyses during a two-year period and will generate a model for carbonate platform and reef evolution within a tectonic framework. Results of the proposed research will refine our understanding of Silurian reef evolution and decline in different tectonic settings, factors affecting Phanerozoic stromatolite development, and the paleogeography of the Alexander terrane.