Global distribution of modern shallow-water marine carbonate factories: a spatial model based on environmental parameters

Marie Laugié,Emmanuelle Poli,Alexandre Pohl,Julien Michel,Jean Borgomano

doi:10.1038/s41598-019-52821-2

Abstract

Prediction of carbonate distributions at a global scale through geological time represents a challenging scientific issue, which is critical for carbonate reservoir studies and the understanding of past and future climate changes. Such prediction is even more challenging because no numerical spatial model allows for the prediction of shallow-water marine carbonates in the Modern. This study proposes to fill this gap by providing for the first time a global quantitative model based on the identification of carbonate factories and associated environmental affinities. The relationships among the four carbonate factories, i.e., “biochemical”, “photozoan-T”, “photo-C” and “heterozoan-C” factories, and sea-surface oceanographic parameters (i.e., temperature, salinity and marine primary productivity) is first studied using spatial analysis. The sea-surface temperature seasonality is shown to be the dominant steering parameter discriminating the carbonate factories. Then, spatial analysis is used to calibrate different carbonate factory functions that predict oceanic zones favorable to specific carbonate factories. Our model allows the mapping of the global distribution of modern carbonate factories with an 82% accuracy. This modeling framework represents a powerful tool that can be adapted and coupled to general circulation models to predict the spatial distribution of past and future shallow-water marine carbonates.

Highlights

Prediction of carbonate distributions at a global scale through geological time represents a challenging scientific issue, which is critical for carbonate reservoir studies and the understanding of past and future climate changes
These trends between carbonate occurrences and oceanography are well integrated in the carbonate classifications of James into photozoan and heterozoan grain associations[7,8] and of Schlager into tropical shallow-water (“T”), cool-water (“C”) and mud-mound (“M”) carbonate factories[9,16,17]; a factory being defined as a carbonate precipitation mode that is characterized by an ecosystem. Continuing these classifications and following the Schlager approach[9], Michel et al.[28] further defined four platform-scale carbonate factories that are the “heterozoan-C”, “photo-C”, “photozoan-T” and “biochemical” factories. Despite these conceptual classifications and apart from the temperature- and salinity-based diagrams of Lees (1975)[15], no numerical spatial model accounting for all types of shallow-water marine carbonates allows for the prediction of carbonate locations at a global scale
The carbonate factory function of Pohl et al.[27] predicts the occurrences of the Cretaceous tropical shallow-water carbonate factory at a global scale based on modelled paleoceanographic parameters and water depth, but it does not make any distinction between the different types of carbonate associations and does not consider cool-water carbonates

Summary

Introduction

Prediction of carbonate distributions at a global scale through geological time represents a challenging scientific issue, which is critical for carbonate reservoir studies and the understanding of past and future climate changes. Continuing these classifications and following the Schlager approach[9], Michel et al.[28] further defined four platform-scale carbonate factories that are the “heterozoan-C”, “photo-C”, “photozoan-T” and “biochemical” factories Despite these conceptual classifications and apart from the temperature- and salinity-based diagrams of Lees (1975)[15], no numerical spatial model accounting for all types of shallow-water marine carbonates allows for the prediction of carbonate locations at a global scale. The carbonate factory function of Pohl et al.[27] predicts the occurrences of the Cretaceous tropical shallow-water carbonate factory at a global scale based on modelled paleoceanographic parameters (sea-surface temperature - SST, sea-surface salinity - SSS, marine primary productivity) and water depth, but it does not make any distinction between the different types of carbonate associations and does not consider cool-water carbonates. Other types of carbonates, including continental carbonates, deep-water coral mounds, carbonate seeps and pelagic carbonates, are not considered here

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