Mineral quantification of a Jordan Cretaceous outcrop (Section GM3, Ghawr Al Mazar, Ghor al Mazrar)

DOI

Cyclic fluctuations in global sea level during epochs of warm greenhouse climate have remained enigmatic, because absence or subordinate presence of polar ice during these periods precludes an explanation by glacio-eustatic forcing. An alternative concept suggests that the water-bearing potential of groundwater aquifers is equal to that of ice caps and that changes in the dynamic balance of aquifer charge versus discharge, as a function of the temperature-related intensity of the hydrological cycle, may have driven eustasy during warm climates. However, this idea has long been neglected for two reasons: 1) the large storage potential of subsurface aquifers was confused with the much smaller capacity of rivers and lakes and 2) empirical data were missing that document past variations in the hydrological cycle in relation to eustasy.In the present study we present the first empirical evidence for changes in precipitation, continental weathering intensity and evaporation that correlate with astronomically (long obliquity) forced sea-level cycles during the warmest period of the Cretaceous (Cenomanian-Turonian). We compare sequence-stratigraphic data with changes in the terrigenous mineral assemblage in a low-latitude marine sedimentary sequence from the equatorial humid belt at the South-Tethyan margin (Levant carbonate platform, Jordan), thereby avoiding uncertainties from land-ocean correlations. Our data indicate covariance between cycles in weathering and sea level: predominantly chemical weathering under wet climate conditions is reflected by dominance of weathering products (clays) in deposits that represent sea-level fall (aquifer charge > discharge). Conversely, preservation of weathering-sensitive minerals (feldspars, epidote and pyroxenes) in transgressive sediments reflects decreased continental weathering due to dryer climate (aquifer discharge > charge). Based on our results we suggest that aquifer-eustasy represents a viable alternative to glacio-eustasy as a driver of cyclic 3rd-order sea-level fluctuations during the middle Cretaceous greenhouse climate, and it may have been a pervasive process throughout Earth history.

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Supplement to: Wendler, Jens E; Wendler, Ines; Vogt, Christoph; Kuss, Hans-Joachim (2016): Link between cyclic eustatic sea-level change and continental weathering: Evidence for aquifer-eustasy in the Cretaceous. Palaeogeography, Palaeoclimatology, Palaeoecology, 441(3), 430-437

Identifier
DOI https://doi.org/10.1594/PANGAEA.834795
Related Identifier https://doi.org/10.1016/j.palaeo.2015.08.014
Related Identifier https://doi.org/10.1594/PANGAEA.834794
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.834795
Provenance
Creator Wendler, Jens E ORCID logo; Wendler, Ines; Vogt, Christoph ORCID logo; Kuss, Hans-Joachim
Publisher PANGAEA
Publication Year 2014
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 3800 data points
Discipline Geosciences; Natural Sciences
Spatial Coverage (35.595 LON, 31.259 LAT); Jordan