Environmental Geometry: Its Effect on and Interaction with Sedimentation: ABSTRACT

Abstract

Environmental geometry is defined as the three-dimensional shape of a locus of sedimentation as delineated by its bathymetry below a base level. Most depositional loci can be considered as open systems that exist within the framework of a larger system. Their geometry is thus nested within a hierarchy of geometric shapes, the largest of which is delineated by oceanic boundaries. Within any locus of deposition at any level in the nest of loci, the distribution, and often the rate of application of energy are functions of (1) the geometry of the locus and (2) the relative position of that locus in the geometrical hierarchy. Therefore, the characteristics of sediments within a locus of known bathymetry can often be predicted from environmental geometry alone. However, the re ative importance of environmental geometry as a parameter which produces sedimentary patterns depends upon the rate of deposition at any one hierarchical level and is most effective at low to medium rates of sedimentation. Since the geometry of the depositional loci at all levels of the nest is interdependent, influences on sedimentary patterns exist between all levels but are most effective between adjacent levels. Multiple non-linear regression provides, in environmental studies, a powerful tool that permits the analysis of the inter-level geometric effects on sedimentation. Examples are presented from estuaries, bays, lagoons, and the continental shelf. End_of_Article - Last_Page 341------------