Last Glacial to Recent: A Sediment Trapping and Long Piston Coring Program in the Gulf of California

由于其地理和海洋学环境，加利福尼亚湾记录了全海洋和区域海洋学和气候信号的混合。极高的沉积速率和频繁出现的年际纹层（varves）使墨西哥湾成为进行高分辨率的古环境变化研究的理想地点，研究范围从季节到千年（甚至更大）。尽管人们一直对墨西哥湾的阀门感兴趣，但这将是第一个使用沉积物捕集器直接确定阀门形成过程的项目。这些结果将有助于更好地理解气候/海洋学记录是如何保存的，这将用于恢复冰期和间冰期沉积物。以下假设将被检验：1)叶片的形成是由风吹陆源物质的季节性输入造成的；2)墨西哥湾东西两侧浅纹层和暗纹层形成的季节时间不同；3)冰期和新仙女木期非层状沉积物的沉积是由于太平洋中深水氧含量的增加和营养物质含量的减少造成的；4)18-0湾的消冰振荡是由盐度降低引起的。可能是由于季风环流增加造成的。

Because of its geographic and oceanographic setting, the Gulf of California records a mix of oceanwide and regional oceanographic and climatic signals. The extremely high rates of sedimentation and frequent occurrence of annual laminae (varves) make the Gulf an ideal location for carrying out high resolution studies of paleoenvironmental change on the seasonal to millenial (and greater) scale. Despite the long interest in Gulf varves, this will be the first project to use sediment traps to directly determine the process of varve formation. The results will lead to a better understanding of how the climatic/oceanographic record is preserved, which will be used in the recover glacial as well as interglacial sediments. Following hypotheses will be tested: 1) that varve formation results from the seasonal input of wind-blown terrigenous material, 2) that the seasonal timing of light and dark laminae formation differs between the eastern and western sides of the Gulf, 3) that the deposition of nonlaminated sediment during glacial and Younger Dryas time resulted from increased oxygen and decreased nutrient content of intermediate depth waters in the Pacific Ocean, and 4) that deglacial oscillations of Gulf 18-0 resulted from episodes of lower salinity, perhaps caused by increased monsoonal circulation.