Romeo M. Flores, 1985. "Coal Deposits in Cretaceous and Tertiary Fluvial Systems of the Rocky Mountain Region", 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 exploitation of coal deposits, whether in strip mines or deep mines, is dependent upon discrete coal bodies that are thick in some places, and thin or absent in others. Over the past few decades, depositional modeling has made possible a greater understanding of the physical characteristics of coal bodies and can be used to explain (or predict) where they are thick, thin, or absent.
Depositional-environment models now available are sufficiently refined so that they can assist not only in solving prohiems in coal exploration and development, but also in mapping hydrocarbon reservoir trends. The usefulness of the concept of coal depositional modeling to petroleum exploration is based on the premise that coal bodies were deposited in an environment juxtaposed to potential hydrocarbon reservoir bodies (e.g., channel sandstone, crevasse-splay sandstone). Thus, the distribution and geometry of coal bodies can he used to predict, identify, and delineate reservoir bodies. Coal is a readily identifiable lithotype in geophysical logs, and its signature is not adversely affected by diagenesis. Because of this advantageous attribute and because of the mutual environmental association of coal and reservoir rocks, coal can he a useful tool in facies-oriented exploration. In order to better understand this method of exploration, attributes of Cretaceous and Tertiary coal-bearing deposits in fluvial systems are examined.
Cretaceous and Tertiary coals were deposited in three major environments in fluvial systems in the Rocky Mountain region: lower alluvial plain of a coastal plain-piedmont setting; upper alluvial plain of a coastal plain-piedmont setting; and intermontane alluvial plain.
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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.