Unconformity between Cretaceous and Eocene rocks in Central-Western Puerto Rico: A concept rejected

Abstract

A major unconformity between rocks of Late Cretaceous and Eocene age in central-western Puerto Rico was previously reported. Recent work suggests that the evidence cited is invalid: (1) because sediments which were interpreted as a basal conglomerate appear to be a fault breccia related (in all areas but one) to gravity sliding; (2) because more extensive mapping has shown that the lithologically distinct Anón Formation, known locally to contain fossils of early Tertiary age, interfingers conformably with formations which contain fossils of Late Cretaceous age. The evidence indicates that deposition in central-western Puerto Rico has been continuous from Late Cretaceous to at least Middle Eocene.