Cratonic sequence
A cratonic sequence in geology is a very large-scale lithostratigraphic sequence in the rock record that represents a complete cycle of marine transgression and regression on a craton over geologic time. They are geologic evidence of relative sea level rising and then falling, thereby depositing varying layers of sediment onto the craton, now expressed as sedimentary rock. Places such as the Grand Canyon are a good visual example of this process, demonstrating the changes between layers deposited over time as the ancient environment changed. Cratonic sequences were first proposed by Laurence L. Sloss in 1963. Each one represents a time when inland seas deposited sediments across the craton. The top and bottom edges of a sequence are each bounded by craton-wide unconformities. The unconformities indicate when the seas receded and sediment was eroded rather than deposited.
language:response_language[Dutch], oulipo:avoid_letter[o]