Wind-deposited, terrestrial carbonate grainstones, formed concurrently with sea-level transgression, comprise the greater part of the Holocene rock record throughout the Bahama Archipelago and are particularly common along windward coastal reaches. In addition to distinctive physical sedimentary structures, most notably large-scale cross-stratification and distinctive fine/coarse-grain couplets, these carbonate eolianites typically contain a diverse assemblage of plant and animal trace fossils.

Rhizomorphs formed by plant roots are near-ubiquitous in Quaternary Bahamian facies and can occur in highly concentrated masses in eolianites. In addition, the aboveground parts of plants and the trailing roots may form distinctive trace fossils and root molds along the bedding planes of eolianites, and tree trunks can be preserved as molds vertical or highly oblique to bedding. The dunal ichnocoenosis also comprises animal trace fossils, including Skolithos linearis formed by tube-dwelling insects and/or arachnids, large cluster burrows formed by digger wasps, large “stellate” burrows likely formed by burrowing bees, and small, irregular burrows formed by insects or insect larvae and concentrated in beds deposited in protected dune lee-slope environments. These small, irregular burrows can result in significant bioturbation of the eolianites. Indeed, the dunal ichnocoenosis commonly exhibits a higher diversity than that found in shallow, subtidal environments, and the burrowing activity of several of its components can produce ichnofabrics distinctive to carbonate eolianites. In a core sample, the occurrence of individual trace fossils or of an ichnofabric should not be used as evidence to rule out an eolian environment.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas