Chicxulub impact ejects from Albion Island, Belize

Impact ejecta from the Albion Formation are exposed in northern Belize. The ejecta come from the outer portion of the continuous ejecta blanket of the Chicxulub crater, which is located 360 km to the northwest. The basal unit of the Albion Formation is a similar to 1-m-thick clay and dolomite sphero id bed composed of up to four discrete flows. The clay spheroids are altere d impact glass, and the dolomite spheroids are accretionary lapilli. The up per unit is a similar to 15-m-thick coarse diamictite bed containing altere d glass, large accretionary blocks, striated, polished, and impacted cobble s, and rare shocked quartz. The abundance of accretionary clasts, evidence for atmospheric drag sorting, and the presence of multiple flows in the Alb ion Formation indicate that atmospheres play an important role in the forma tion of the outer portions of continuous ejecta blankets of large craters. (C) 1999 Elsevier Science B.V. All rights reserved.