Origin of Silt in the Permian Phosphoria Formation

二叠纪Phosphoria组粉砂岩相的成因AlanCarrollt-0106898粉砂质海相泥岩是体积上最重要的沉积岩类型之一，但其成因仍然知之甚少。拟议的研究将调查粉砂岩相内的二叠纪Phosphoria形成在美国西部的区域沉积和地层调查将进行评估的重要性，悬浮沉降与其他沉积过程，并检查粉砂岩和其他相的关系，以改变海平面。 不同石英粒度组分的氧同位素分析将用于限制其结晶温度，从而限制其来源（再加工石英与原生石英）。 最后，将在一些广泛分布的地点测量粉砂岩和其他粉质相的粒度分布。 这些测量，结合高分辨率地层研究，将被用来检查整个磷海的粒度趋势。

ABSTRACTOrigin of Siltstone Facies in the Permian Phosphoria FormationAlan CarrollEAR-0106898Silty marine mudrocks represent one of the most volumetrically important sedimentary rock types, but their genesis remains very poorly understood. The proposed study will investigate siltstone facies contained within the Permian Phosphoria Formation in the western U.S. A regional sedimentologic and stratigraphic investigation will be conducted to assess the importance of suspension settling versus other depositional processes, and to examine the relationship of siltstone and other facies to changing sea level. Oxygen isotopic analyses of different quartz grain size fractions will be used to constrain their temperature of crystallization and thus their origin (reworked versus primary quartz). Finally, grain size distributions from siltstone and other silty facies will be measured at a number of widely distributed sites. These measurements, combined with high-resolution stratigraphic studies, will be used to examine grainsize trends across the Phosphoria sea.