دانلود کتاب The Alaskan Shelf: Hydrographic, Sedimentary, and Geochemical Environment

From a general point of view the importance of striving to minimize envir- mental disturbances on the continental shelf cannot be overemphasized. Coastal areas are sites of population centers, navigation and recreation activities, and - source development, all of which contribute to environmental stress on the shelf. Proper management of the shelf for optimum use requires a thorough understanding of shelf processes. Complex problems, such as the influence of hydrodynamics on sediment dispersal, element differentiation and migration, physiochemical changes at the sediment water interface, the relationship - tween the pollutants and sediments, and the type of substrate with regard to benthic community and/or man-made structures require a multidisciplinary approach to their solution. The present study interrelates meteorologic, hyd- graphic, sedimentologic, and geochemical parameters to derme specific envir- ments on the Alaskan Shelf. These observations are then related to geologic principles in an effort to elucidate the sedimentary processes and elemental migration on the shelf. Attempts have also been made to relate the sediment texture to the geochem- try of the sediments. Obviously the chemistry is complicated as a result of b- genic contributions and variable provenance; however, to some extent elemental differentiation accompanies textural differentiation in sediments. The distribution of elements in various phases of crustal (source) rocks is gen- ally interpreted on the basis of crystallographic concepts, especially the concept of isomorphism.