Ichnofacies and Ichnofabric Analysis of Pelagic and Hemipelagic Deposits (Upper Cretaceous-Tertiary), South Island, New Zealand

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The research proposed focuses on the ichnology of pelagic and hemipelagic deposits in New Zealand. The scientific objectives involve the endobenthic paleoecology, sedimentology and evironmental stratigraphy of pelagic and hemipelagic deposits exposed in the northeastern part of the South Island of New Zealand, as determined from biogenic sedimentary fabrics (ichnofabrics) and characteristic trace fossil associations (ichnofacies). The study will focus on fine-grained, deep-water marine carbonate, marl and clay units in the Amuri Group (Upper Cretaceous to Upper Eocene in age). Particular emphasis will be on endobenthic community paleoecology (i.e., tiering relationship of infaunal animals deduced from composite ichnofabrics), ichnofacies relations (i.e., the geologic significance of particular trace fossil assemblages that exemplify certain sedimentologic regimes and depositional environments) and biogenic controls on early diagenesis (e.g., preferential cementation phosphatization and/or chertification of trace fossils). In addition, cyclic repetition of certain ichnofacies (e.g., Thalassinoides-dominated, Zoophycos-dominated and/or Chondrites-dominated zones) will be interpreted in relation to current ideas of regional tectonism, global eustacy, and orbital forcing of worldwide atmospheric and oceanographic events.