The results of experimental investigations on turbidity currents of high density are described. Hydrodynamical properties are deduced which permit tentative extrapolation to the larger dimensions which may be expected in nature. The results are applied to the problem of submarine canyons. The reasons, given in an earlier paper, why the deposits tend to be graded are confirmed and the possibility of erosion is discussed. Settling velocities of said grains in clay and clay-sand suspensions are given and the influence of salinity is investigated. Viscosity measurements of clay suspensions are recorded. An attempt is made to find properties by which the deposits of ancient turbidity currents can be distinguished from those of normal processes of sedimentation. Filially, the problem is reviewed as to whether slumping or turbidity currents have played the major role in forming submarine canyons.
Figures & Tables
By 1951, recent studies of the sea floor were forcing drastic revisions of many of our basic geological concepts. The concept of vertical stability of the ocean basins was being challenged by the discovery of “guyots”; sea-mounts whose flat tops, now several thousand feet beneath the sea surface, give evidence of wave truncation. The belief that the deep ocean floor was essentially a flat, featureless plain was completely discredited by the discovery of fault scarps and mountain ranges comparable in size and complexity to any of those existing on the continents. One of the most challenging of recent discoveries is the finding of relatively coarse sediments (coarse silt and sand) in deep basins and on the open ocean floor at depths of several thousand feet and many miles from land. Solution of this problem was particularly difficult because the mere occurrence of these coarse sediments violates some of the traditional opinions of the day about processes operating in the oceans. This volume contains some of the first and best documented research in this area that opened a whole new way to interpret deep water deposition.