Florida Escarpment: Genesis, Geomorphology and Seepage Processes

1986年期间，有两次非常成功的巡游前往佛罗里达悬崖，产生了非常令人兴奋的数据。用“深海拖网”对两个地点进行了调查，对悬崖的代表性地段进行了海床覆盖，12次阿尔文潜水主要在化学“SEEP”社区的地点进行，那里进行了详细的地球化学和地质采样。该计划的目标是：1)详细描述陡峭(-45度)石灰岩悬崖的形态和生成过程，并建立悬崖本身与渗出到其底部海底的硫化物/产甲烷孔隙流体之间的关系，2)确定渗漏流体中减少的化学物质的来源，并了解与渗漏有关的海底过程的范围；3)确定这些过程产生的沉积的性质，并确定在岩石记录中识别它们的标准。这个项目之前的工作揭示了佛罗里达州附近一个看起来是侵蚀的匿名陡峭的悬崖。悬崖底部的样本显示，硫化物沉积物是由于石灰岩中的流体喷发而形成的。为了更好地了解排气过程，将使用它们留下的化学沉淀物来研究这些流体的化学成分。现代记录的结果将使人们能够更好地识别岩石记录中的这些过程。

Two very successful cruises were taken to the Florida Escarpment during 1986 that are yielding very stimulating data. Two sites were surveyed with "Deep-Tow", representative sections of the escarpment were seabeamed, and twelve ALVIN dives were conducted mostly at sites of chemosnythetic "seep" communties where detailed geochemical and geological sampling was conducted. The program objectives are: 1) to detail the morphology and processes of generation of the steep (-45o) limestone escarpment, and to establish the relationship between the escarpment itself and the sulfidic/methanogenic pore-fluids which seep out onto the seafloor at its base, 2) to determine the source of the reduced chemicals in the seeping fluids and to understand the range of processes which are occurring at the seafloor associated with the seeps, and 3) to characterize the nature of the deposits generated by these processes, and to establish the criterion for their recognition in the rock record. %%% Previous work on this project has revealed an anonymously steep escarpment off Florida that appears to be the result of erosion. Samples from the base of the escarpment reveal sulfide deposits that have formed in response to venting of fluids from the limestone rocks. The chemistry of these fluids will be investigated using the chemical precipitates they have left behind in order to better understand the venting process. The results from the modern record will allow better recognition of these processes in the rock record.