Punctuated Aggradational Cycles: A General Hypothesis of Episodic Stratigraphic Accumulation

摘要: According to the hypothesis of punctuated aggradational cycles presented here, stratigraphic record consists small-scale (1-5 m thick) shallowing-upward (PACs) separated by surfaces marked abrupt change deeper facies. This motif, pervasive in time and environment, is produced relatively long periods (tens thousands years) base-level stability geologically instantaneous relative rises at least basin-wide extent. As lithologic time-stratigraphic units, PACs are fundamental all aspects analysis including correlation, paleoenvironmental interpretation, paleogeographic reconstruction. Of several possible allogenic mechanisms for a pervasively cyclic record, glacial eustasy driven orbital perturbations preferred. The PAC as comprehensive model be tested modified examination from an episodic perspective.