Parsing autogenic and allogenic processes in aeolian stratigraphy

I am beyond excited to present highly collaborative work that begins to parse records of autogenic processes and allogenic forcings preserved within set-scale aeolian architecture in two companion articles: (1) numerical experiments (preprint) and (2) the scour-fill dominated Jurassic Page Sandstone, Arizona (preprint).

synStrat
Set-scale aeolian architecture from a numerical model of dynamic dune topography driven by steady allogenic boundary conditions. Color represents time of deposition.

In the first companion article, a reduced complexity model of aeolian dune strata-formation is developed and applied to explore the roles of autogenic processes on the preservation of allogenic sourced from three sets of external environmental forcing. In each scenario, rapid dune growth is found to completely cannibalize early dune deposits, thus shredding any records of early allogenic or autogenic signals. However, later dune deposits are found to contain commingled autogenic and allogenic signals. This theoretical work frames five working hypotheses surrounding the nature of aeolian dune deposits for future workers to explore and discuss! The source code (Matlab) will reproduce all figures in this article is available here. A Python version is planned.

cardenasJSR2018
Page Sandstone. Early dune deposits (smaller sets in B,D) are preferentially preserved in antecedent lows in paleotopography.

In the companion article, collaborator Benjamin Cardenas leads interpretation of set-scale aeolian architecture within multiple exposures of the Page Sandstone (Jurassic) near Page Arizona, USA. This work interprets the set-scale architecture of the Page Sandstone to record multiple transgressions of the Carmel Sea. Drying, and associated decreases in base-level between transgressions liberates significant quantities of sand.  After drying, dune growth and scour are interpreted to cannibalize early dune deposits, except for those created in antecedent lows in paleotopography. Ongoing dune motion in the dry sand sea creates scour and fill architecture which is thought to characterize autogenic dune behavior. Eventually, the Carmel Sea completely transgresses the sand accumulation, and shuts down the aeolian system at the end of the Page (pun intended).

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