Weathering and the Riverine Denudation of Continents

Abstract

Continental denudation has been the center of attention of a reduced and select group of outstanding specialists for several decades. The foci have been placed in queries such as how much solid and dissolved material is annually removed from the continents by rivers and how much water is involved in the process?; which are the forcing variables and processes in continental wearing away?; is climate more important than lithology in defining the rate of denudation?, where and when?; how much height do continents recuperate through isostatic rebound as a consequence of denudation?; are weathering and denudation connected in a straightforward way? These and other similar questions became particularly important several years ago, when it turned out that weathering and denudation were linked to climate change, nowadays or in the geological past. The joint action of weathering and denudation has played, for example, a significant role in the formulation of the amazing hypothesis of the ??Snowball Earth,?? which appears to have occurred occasionally about 650 million years ago. On the other hand, there exists the additional anthropogenic impact that adds complexity to the current scenario because it may amplify erosion in ill-managed areas and, hence, increase sediment retention behind dams. We have written this Brief Monograph, using classic references and case studies, trying to direct the reader's attention to the simple fact that continental denudation begins with weathering. Rivers constitute the amazingly efficient conveyor belt system that performs the main task in transferring most of the solid debris and dissolved substances thus produced, to the coastal ocean. At the same time, we must not disregard the fact that, in so doing, they contribute to sustain a very dynamic and diverse life-supporting system, in the rivers themselves as well as in estuaries and the adjacent marine environment. On account of its conciseness, this brief book should be viewed as a stepping stone for those who wish to pursue this subject further on and, also, as an invitation to some deeper digging into the weathering-denudation system in a multidisciplinary way.