Carbonate platform production during the Cretaceous

Abstract

Platform carbonates are among the most voluminous of Cretaceous deposits. The production of carbonate platforms fluctuated through time. Yet, the reasons for these fluctuations are not well understood, and the underlying mechanisms remain largely unconstrained. Here we document the long-term trend in Cretaceous carbonate platform preservation based on a new data compilation and use a climate-carbon cycle model to explore the drivers of carbonate platform production during the Cretaceous. We show that neritic carbonate preservation rates followed a unimodal pattern during the Cretaceous and reached maximum values during the mid-Cretaceous (Albian, 110 Ma). Coupled climate-carbon cycle modeling reveals that this maximum in carbonate deposition results from a unique combination of high volcanic degassing rates and widespread shallow-marine environments that served as a substrate for neritic carbonate deposition. Our experiments demonstrate that the unimodal pattern in neritic carbonate accumulation agrees well with most of the volcanic degassing scenarios for the Cretaceous. Our results suggest that the first-order temporal evolution of neritic carbonate production during the Cretaceous reflects changes in continental configuration and volcanic degassing. Geodynamics, by modulating accommodation space, and turnovers in the dominant biota probably played a role as well, but it is not necessary to account for the latter processes to explain the first-order trend in Cretaceous neritic carbonate accumulation in our simulations.

The mantle, CO2and the giant Aptian chemogenic lacustrine carbonate factory of the South Atlantic: Some carbonates are made, not born

“…The early (Aptian–Albian) Cretaceous is regarded as an interval when high rates of volcanic CO 2 in the atmosphere led, via high rates of silicate weathering, to high rates of shallow water carbonate production in the oceans (Pohl et al ., 2020). However, the lakes which produced the BVF and its equivalents were not linked to the Aptian oceans.…”

“…The role of tectonics involves those large‐scale processes affecting rates of continental crustal weathering but also seawater–basalt reactions at spreading ridges, and also serpentinization of exhumed mantle. A view has been reached that atmospheric CO 2 levels are a critical factor in release of the required ions for carbonate accumulation, including high rates of volcanic degassing of CO 2 , which have been proposed as a critical factor in the high neritic carbonate preservation and production rates which characterize the mid‐Cretaceous (Pohl et al ., 2020).…”

Marine carbonate factories: Review and update

“…(2018, 2019) subdivision is a useful addition as it highlights possible diversifications within each factory depending on the dominance of location‐specific environmental factors. Modelling experiments for the Cretaceous (Pohl et al ., 2019, 2020) using the aforementioned subdivision together with a coupled ocean‐atmosphere general circulation model and palaeo‐bathymetry estimates, which were partially based on literature data, produced detailed carbonate factory distribution maps at a global scale for this time period.…”

Stratigraphic evolution and karstification of a Cretaceous Mid‐Pacific atoll (Resolution Guyot) resolved from core‐log‐seismic integration and comparison with modern and ancient analogues

“…The rapid initial subsidence combined with the Hauterivian long‐term sea‐level rise (Haq, 2014) resulted in rapid creation of accommodation facilitating the deposition of transgressive Seismic Unit‐1. The study by Pohl et al (2020; anchored on GTS2012) showed that neritic carbonates production reached the maximum between ca. 120 Ma and 80 Ma preceded by an increase in the production between ca.…”

“…100.5 ± 1 Ma between onset and drowning of the carbonate platform. In Section 5.2, the updated age-model is used to compare our record with the Haq (2014) revised eustatic record andPohl et al (2020) carbonate production trends as they are all anchored on the same geologic time scale(Gradstein et al, 2012).…”