Carbonate Cementation beneath Marine Flooding Surfaces, Upper Cretaceous, Book Cliffs, Utah

Laterally persistent carbonate cementation, in the form of concretions or cemented horizons, is common within shallow marine sandstones reservoirs. Understanding the distribution of such cemented zones is of immense value, as within the subsurface they may lead to reservoir compartmentalisation and associated production problems. However, the exact sedimentological and stratigraphic relationships of these cemented horizons are generally lacking as the majority of studies have been undertaken on borehole material or outcrops of limited lateral extent. In this paper the field relationships between cementation and stratigraphy from the exceptionally well-exposed Upper Cretaceous sediments in Book Cliffs, Utah-Colorado are documented. We show that laterally persistent cemented horizons consistently occur beneath major marine flooding surfaces and propose that the initial precipitation of these cemented horizons took place at periods of markedly reduced sediment accumulation rates associated with these flooding events.