loading page

Carbonates in the Critical Zone
  • +6
  • Matthew David Covington,
  • J B Martin,
  • L E Toran,
  • J L Macalady,
  • N Sekhon,
  • P.L. Sullivan,
  • Á A García,
  • J B Heffernan,
  • W D Graham
Matthew David Covington
Department of Geosciences, University of Arkansas, ZRC SAZU, Karst Research Institute, Slovenia

Corresponding Author:[email protected]

Author Profile
J B Martin
Department of Geological Sciences, University of Florida
L E Toran
Department of Earth and Environmental Science, Temple University
J L Macalady
Department of Geosciences, Pennsylvania State University
N Sekhon
Department of Earth, Environmental and Planetary Science
P.L. Sullivan
College of Earth, Ocean, and Atmospheric Science, Oregon State University
Á A García
Department of Geology and Environmental Science, James Madison University
J B Heffernan
Nicholas School of the Environment, Duke University
W D Graham
Department of Geological Sciences, University of Florida, Geology and Environmental Science, Nicholas School of the Environment, James Madison University, Duke University, University of Florida


Earth’s Critical Zone (CZ), the near-surface layer where rock is weathered and landscapes co-evolve with life, is profoundly influenced by the type of underlying bedrock. Previous studies employing the CZ framework have focused primarily on landscapes dominated by silicate rocks. However, carbonate rocks crop out on approximately 15% of Earth’s ice-free continental surface and provide important water resources and ecosystem services to ~1.2 billion people. Unlike silicates, carbonate minerals weather congruently and have high solubilities and rapid dissolution kinetics, enabling the development of large, interconnected pore spaces and preferential flow paths that restructure the CZ. Here we review the state of knowledge of the carbonate CZ, exploring parameters that produce contrasts in the CZ in different carbonate settings and identifying important open questions about carbonate CZ processes. We introduce the concept of a carbonate-silicate CZ spectrum and examine whether current conceptual models of the CZ, such as the conveyor model, can be applied to carbonate landscapes. We argue that, to advance beyond site-specific understanding and develop a more general conceptual framework for the role of carbonates in the CZ, we need integrative studies spanning both the carbonate-silicate spectrum and a range of carbonate settings.
20 Dec 2022Submitted to ESS Open Archive
27 Dec 2022Published in ESS Open Archive
26 Dec 2022Published in Earth's Future. 10.1029/2022EF002765