Geological event

[1] Geological events range in time span by orders of magnitude, from seconds to millions of years, and in spatial scale from local to regional and, ultimately, global.

[2] In contrast to chronostratigraphic or geochronological units, that define the boundaries between periods, epochs and other units of the geologic time scale, complex dynamic diachronous changes are inherent to the event-stratigraphy paradigm.

The lithostratigraphic or biostratigraphic boundaries that mark the onset and termination of geological events in the stratigraphic record may be diachronous, whereas those of formal chronostratigraphic or geochronologic units have basal boundaries that are isochronous.

The event paradigm is firmly embedded in Quaternary science, as the subdivision of quaternary time is based on the recognition of a succession of climatic events, principally glacial and interglacial cycles but also stadials and interstadials.

Highly resolved stratigraphic sequences, such as those from ice cores, provide evidence of much shorter-term millennial-scale climatic events that are superimposed on these broad glacial cycles.