Abstract
Abstract The shallow-marine deltaic sandstones and shales of the Lower Carboniferous Mullaghmore Sandstone, northwest Ireland, contain abundant trace fossils. A twenty-five metre thick measured section of Mullaghmore Sandstone from the northwest corner of Mullaghmore Head contains a minimum of twenty-eight ichnogenera and four informally named trace fossils. At least four coarsening-upward sequences occur within the measured section, with a possible total of six. Sedimentary structures and trace fossils indicate that each sequence represents deposition in a shallow-marine deltaic environment; prodelta-interdistributary bay passing upwards into a subaqueous channel environment. These represent a Cruziana -type ichnofacies, with an interbedded tempestite-associated Arenicolites ichnofacies, and a Skolithos -type ichnofacies respectively. The ichnogenus Neonereites , more typical of the Nereites ichnofacies, also occurs within the Cruziana ichnofacies, but only in limited numbers, and is atypical of the ichnofauna. Local lateral variation in ichnogenera and their sporadic occurrence along bedding planes indicates the need for extensive investigation, if trace fossils are to be used for detailed environmental reconstruction.
Published Version
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