Marine Carbonate Factories and Stratigraphic Response Through Time and Space: Methodology, Examples and Implications

Abstract:

A new and innovative workflow predicts presence, type and thickness of marine carbonates through geological Time and Space. It couples exhaustive data mining, accurate paleogeography and deep time paleoclimate modeling to reveal the waning and waxing of carbonate deposition throughout geological history with many, yet unmapped, implications for geosciences and industry alike.

The intimate link between modern shallow-water marine carbonate deposition and paleoecological parameters (e.g. salinity, water temperature, nutrients, bathymetry) has been recognized in the public domain in the last decennia and was recently elegantly confirmed through satellite mapping of modern carbonate ecological systems to aforementioned parameter space. Applying similar concepts to the geological record has had limited success in part due to the complexity of defining paleoecological proxies, insufficient data quality and ability to handling data quantity. Though it has been clear that marine carbonates in geological time and space are not randomly distributed it was the concept of “carbonate factories” that allowed the estimation of the ranges of associated ecological parameters, to a dominant carbonate precipitation mode and to a specific depositional geometry of carbonate accumulation, subsequent coupling with deep time paleoclimate modeling.

This paper shares a new and innovative workflow that combines: 1) GIS compilation of exhaustive internal, public and commercial databases; 2) generation of accurate paleogeographic maps and, in particular, paleobathymetry; 3) advanced deep time paleoclimate modeling using different model codes (IPSL-CM5A2 vs. MITgcm); 4) sensitivity tests of, for example, paleogeographic scenarios, carbonate factories and ecological functions; 5) statistical modeling generating probability maps; 6) determination and modeling of thickness ranges and anatomy of carbonates through forward stratigraphic modeling. Comparison of time series provides a first insight in the subtle relationship between carbonate systems, their spatial expansion and volumetrics, but also biotic, climatic and paleogeographic changes. Finally, this work illustrates how the results, for a selected number of time slices, assist both geoscience and industry.