Frank G. Ethridge, 1985. "Surface and Subsurface Methods of Investigation and Classification of Fluvial Systems", Recognition of Fluvial Depositional Systems and their Resource Potential, Romeo M. Flores, Frank G. Ethridge, Andrew D. Miall, William E. Galloway, Thomas D. Fouch
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The objectives for the first day of the course are to review sediment processes that result in erosion, transportion and deposition in modern fluvial systems, and to present criteria and models that are used to reconstruct ancient fluvial and related deposits. The criteria and models were developed, for the most part, from studies of modern depositional environments. Although environments can be erosional, equilibrium or depositional in nature, it is the Depositional Environment that will be our principal concern. The depositional environment is preserved in the rock record as a three-dimensional body with framework (usually sandstones and conglomerates) and non-framework (usually mudstones) deposits. Assemblages of related depositional environments are referred to as Depositional Systems.
Another equally important objective is to apply the knowledge of modern and ancient environments to the practical problems of exploring for an exploiting mineral and fossil fuel resources that rty be contained within ancient fluvial deposits. This aspect of the course will be covered on the second day.
Reconstruction of ancient depositional environments in stratigraphic sequences is based on two fundamental concepts. The first, Johannes Walther's Law of Facies (1894) states: “a conformable vertical sequence of facies was generated by a lateral sequence of environments” (Selley, 1976). The second concept, stated by Visher (1965) and formalized by Selley (1976)specifies that there are a finite number of sedimentary environments and processes on the earth's surface and a finite number of idealized vertical sequences that occur in time and space in the geologic record. If recognized these idealized sequences
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The understanding of fluvial environments and processes that operate within them as well as their products in the geological record is a recent development. During the past decade, facies analysis of fluvial rocks has been increasingly used to explore for and develop hydrocarbons, coal, uranium and metallic minerals. The rapid growth in the database on fluvial depositional systems coupled with the need to recognize the economic potential of their deposits has yielded numerous resources which deal with recognition and classification of the whole spectrum of fluvial systems, fluvial processes and their products, facies models of ancient fluvial deposits, and application of fluvial models to resource exploration and development. This notebook is an outgrowth of the burgeoning geological investigations of fluvial rocks and their associated potential. The notebook is divided into 11 chapters the cover methodology and classification of fluvial systems as well as modern and ancient deposits of alluvial fans, fan deltas, braided systems, meandering streams and anastomosed streams. In addition, application of facies modeling to exploration and development of hydrocarbons, coal and uranium is discussed for the Rocky Mountain region, Mid Continent, Gulf Coast and western China.