TABLE OF CONTENTS A sedimentary basin is an area of the earth s crust that is underlain by a thick sequence of sedimentary rocks. Hydrocarbons commonly occur in sedimentary basins and are absent from intervening areas of igneous and metamorphic rocks (North, 1971). This fundamental truth is one of the cornerstones of the sedimentary-organic theory for the origin of hydrocarbons. (This theory is in opposition to the cosmic-igneous theory discussed in Chapter 5.) Therefore it is important to direct our attention not only to the details of traps and reservoir rocks but also to the broader aspects of sedimentary basin analysis. Before acquiring acreage in a new area, and long before attempting to locate drillable prospects, it is necessary to establish the type of basin to be evaluated and to consider what productive fairways it may contain and where they may be extensively located. This chapter describes the various types of basin with reference to examples from around the world and discusses the relationship between the genesis and evolution of a basin and its hydrocarbon potential.
First, however, some of the basic terms and concepts must be defined. A sedimentary basin is an area on the earth s surface where sediments have accumulated to a greater thickness than they have in adjacent areas. No clear boundary exists between the lower size limit of a basin and the upper limit of a syncline. Most geologists would probably take the view that a length of more than 100 km and a width...
