Abstract

The Upper Cretaceous Barton Creek formation (a tan to grey limestone and dolostone) is the youngest unit in the Corozal basin of northern Belize. This formation ranges from about 1600 to about 2500 ft thick (488 to about 761 m). The Barton Creek is underlain by the petroleum-bearing Yalbac formation (an entirely subsurface unit) and unconformably overlain the Belize ‘KT’ boundary interval (Albion formation and lateral equivalents) and/or the Lower Paleogene El Cayo group. The Barton Creek weathers deeply and is host to significant karst development. There are five main outcrop areas of Barton Creek across northern Belize, which may be related to large, underlying structures, and two other significant outcrop sites. Exposures at these places allow for a general description of the depositional environments of the Barton Creek (mainly near shore and shelfal) and are useful in a forming a general paleogeography for the upper part of the formation. An isopach map of the formation shows that thickness varies relatively little over the whole of the Corozal basin, which suggests that the formation developed after significant deepening of the basin had ended. The relatively abrupt truncation of the 1600 ft (488 m) thick Barton Creek formation at the foothills of the Maya Mountains suggests that mountain development largely postdated deposition of this formation.