Cycles with Episodicities of Less than One Million Years

Abstract

Cycles of 10⁴–10⁵ years duration can be grouped into five main types (Sects. 7.2, 7.3, 7.4, 7.5, and 7.6), reflecting their stratigraphic composition, tectonic setting, and age. Many of these cycles are thought to have been generated by global climate changes driven by orbital forcing, the so-called Milankovitch mechanisms, as described in Chap. 11. The term derives from the name of the Yugoslavian mathematician who was the first to provide the mathematical basis for the theory of astronomical forcing (Milankovitch, 1930, 1941). However, there is increasing evidence of the tectonic origin of some of the clastic cycles in foreland basins (Sect. 7.6), as discussed in Chap. 10.