The Eolian Sedimentary Record: What Do We Know and Where Are We Going?

Abstract

The sedimentary record of most modern eolian dune fields remains largely unknown; correspondingly, relatively few ancient eolian successions are known that preserve original bedform morphologies intact. As such, models that attempt to relate eolian bedform morphology and migratory behavior to resultant sedimentary architectures tend not to capture and account for the full range of complexity known from either modern systems or their ancient preserved counterparts. This study provides a review to assess the current state of eolian sedimentological research and to suggest future research direction. Some obvious questions that remain to be answered are as follows: (i) what factors control the preservation potential of different types of eolian bedforms and what specifically are the characteristics of deposits of different bedform types that can be used for effective and reliable reconstruction of original bedform morphology; (ii) why do the majority of paleoenvironmental reconstructions of eolian systems envisage transverse (and related barchanoid) dune types, whereas successions representing linear, star and other bedform types remain apparently under-recognized; (iii) what proportion of the known eolian preserved record arose via sustained episodes of bedform climb versus episodic sequence and supersurface generation, respectively; (iv) what specific sets of controlling conditions allow for sustained bedform climb versus episodic sequence accumulation and preservation; (v) can sophisticated 4D models be developed with which to account for complex patterns of spatial and temporal transition between different mechanisms of accumulation and preservation and, if so, will such models be dependent on the development of high-resolution dating techniques, meaning that they will likely be best suited to the analysis of Quaternary eolian successions; (vi) given that a rather specific set of controlling conditions are required for eolian system construction, accumulation and preservation, is it reasonable to assume that the deposits of preserved eolian successions necessarily represent an unbiased record of the conditions that prevailed during episodes of Earth history when large-scale eolian systems were active; (vii) from an applied standpoint, what novel approaches can be devised for modeling lithological heterogeneity in eolian hydrocarbon reservoirs, groundwater aquifers and successions suitable for long-term subsurface carbon storage?

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019