Within the framework of plate tectonics, it has been long been recognized that this subsidence is a consequence of the much larger horizontal translations of the plates. As Dickinson (1974, p. 2) wrote:

Plate-tectonic theory as a geometric paradigm to explain tectonic patterns lays special emphasis . . . on grand horizontal translations of the lithosphere with its capping of crust. However, major vertical motions of the crust and lithosphere are required to accompany the horizontal motions by any feasible geologic interpretations of the mechanisms of plate motions and interactions. The vertical motions are related to changes in crustal thickness, in thermal regime, and in conditions for isostatic balance. These three facets of plate-tectonic theory postulate inherent vertical motions of an order that no previous tectonic theory can match in overall scope.

Basin Subsidence

Geologic observations and modeling studies have identified seven processes that can initiate and sustain basin subsidence (Dickinson, 1974, 1976, 1994; Ingersoll and Busby, 1995) (see Table 1). Most basins involve several of these processes working together. The mechanisms of basin subsidence are complex because the forces operate on a wide range of length and time scales, and they interact with the heterogeneous properties of Earth materials in subtle ways. With few exceptions, the exact pathways of basin subsidence cannot be predicted from a general knowledge of the distribution of forces, energy, and material properties. Understanding the subsidence of specific basins requires a comprehensive approach involving both theoretical and experimental work complemented by diverse geologic observations. New theoretical concepts and technologies suggest that there are large opportunities for intellectual advances. Addressing the processes of basin initiation and evolution over the broad scale of the mantle and crust is the ultimate key to understanding the thermal history of the lithosphere and the economic potential of basins.

To this end, there has been considerable effort to classify sedimentary basins based on their affinity with particular tectonic provinces and processes. With this approach, Ingersoll and Busby (1995) have



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