Distribution of Chicxulub ejecta at the Cretaceous-Tertiary boundary

The mineralogical, sedimentological, and geochemical information in a large database on the Cretaceous-Tertiary (K-T) boundary is used to document the distribution of impact debris derived from the Chicxulub crater. The database is coupled with a geographic information system (GIS) allowing the plotting of the information on a latest Cretaceous paleogeographic map. The database will be available in part on the internet in the near future, and contains data from 345 K-T boundary sites worldwide. However, relatively few sites are known in South America, Australia, Africa, and in the high latitudes. Major disturbances of sedimentation, such as massive debris flows, failure of platform margins, or significant erosion of Upper Cretaceous layers, occur throughout the Gulf of Mexico. Mass wasting of material also took place in the western and eastern parts of the Atlantic Ocean. Almost 100 K-T boundary sites analyzed for Ir recorded the positive anomaly; Ir is spread homogeneously throughout the world, but is diluted at proximal sites because of the high volume of sediment that was in suspension in the Gulf of Mexico after the impact. Shocked quartz is more common, and maybe larger in size west of the crater. The main advantage of the database is to provide a convenient method to manage the huge amount of data available in the literature, and to reveal patterns or characteristics of the data. The database can help refine the variables used in mathematical models and documents the origin, transport, and deposition of ejecta during a cratering event.