GSSPS (GLOBAL STRATOTYPE SECTION AND POINT) AND CORRELATION

Time correlation of stratigraphic successions - chronostratigraphy - is essential for recognizing and interpreting geologic events recorded within them, for reconstructing the history of the Earth System, and for exploration of sediment hosted mineral and energy resources. Chrono-correlation is an interpretive process that involves evaluation of varied stratigraphic signals (or proxies) from lithostratigraphy, biostratigraphy, chemostratigraphy, magnetostratigraphy, and sequence stratigraphy as well as numerical ages. It is expressed in the units of the ICS International Chronostratigraphic Chart, the basis for the Geologic Time Scale. The global-standard chronostratigraphic units (Systems, Series, Stages) are defined by GSSPs. Accordingly, the essential criterion for approving a GSSP must be the demonstration of a high potential for correlation across a range of paleogeographic and paleoenvironmental settings. Otherwise, the units will not be adequate to express unambiguous global correlations that are reliable and of high resolution. Having been shown to be inadequate for reliable, high-resolution correlation is the only reason that some of approved GSSPs must now be reconsidered.