Webinar: TALES FROM TWO SHELL BEDS: THE ROLE OF SEDIMENTATION REGIME IN THE PRESERVATION OF HIGH-PRODUCTIVITY SKELETAL CONCENTRATIONS

TALES FROM TWO SHELL BEDS: THE ROLE OF SEDIMENTATION REGIME IN THE PRESERVATION OF HIGH-PRODUCTIVITY SKELETAL CONCENTRATIONS

• Tuesday, January 25, 2022
• 12:00 PM  1:00 PM MT

• Madeline S. Marshall

  Albion College

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  High-productivity systems are known to host a diversity of life, along with distinctive sediments such as phosphorites, organic-rich muds, and glauconitic sands. Additionally, elevated productivity has the potential to influence concentrations of skeletal material through multiple interacting ecological, taphonomic, and diagenetic effects in the seabed. Previous study of the Permian Phosphoria Rock Complex (PRC) of the Intermountain West has focused on these variables, finding preservation of skeletal concentrations to be dictated largely by the sequence stratigraphic context and duration of hiatuses in sedimentation. 

  The current study considers another key component to more fully understanding the problem of preservation in high-productivity systems: sedimentation regime and input of clastics. Variation in the amount of dilution by clastics that high-productivity systems experience can have profound impacts on the subsequent preservation of fossil material: sediment starvation often occurs in tandem with low-energy and dysoxic conditions, while systems rich in clastic input are typically higher energy and better oxygenated. A comparative analysis of the sediment-starved Permian PRC and the sediment-rich late Jurassic record of the southern Morondava Basin, Madagascar, is a first step in tackling this problem.