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Title: | Early Miocene intensification of the North African hydrological cycle : multi‐proxy evidence from the shelf carbonates of Malta |
Authors: | Zammit, Ray Lear, Caroline Samankassou, Elias Lourens, Lucas Micallef, Aaron Pearson, Paul Bialik, Or M. |
Keywords: | Paleoclimatology -- Miocene Paleoclimatology -- Oligocene Paleoclimatology -- Malta Climatic changes -- Mediterranean Region Carbonates -- Malta |
Issue Date: | 2022 |
Publisher: | Wiley |
Citation: | Zammit, R., Lear, C. H., Samankassou, E., Lourens, L. J., Micallef, A., Pearson, P. N., & Bialik, O. M. (2022). Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta. Paleoceanography and Paleoclimatology, e2022PA004414. |
Abstract: | During the Miocene (23.0–5.3 Ma) North Africa experienced both humid and arid intervals, but the underlying cause of these transitions is unknown. Earth's climate was characterized by a unipolar icehouse with a dynamic Antarctic ice sheet, which may have influenced regional hydrology through atmospheric teleconnections. However, the Miocene also witnessed the restriction of the Mesopotamian Seaway, which may have had significant climatic impacts. The Maltese il-Blata section (Central Mediterranean) comprises Late Oligocene to Early Miocene marine deposits previously used to constrain the timing of the Mesopotamian Seaway restriction using the εNd tracer. The location of this section also makes it sensitive to climatic changes in the North African region, and biogeochemical changes in the central Mediterranean. Here, we present lithological and geochemical records of the il-Blata section. We find a marked shift in lithology and an increase in sedimentation rate coeval with the Early Miocene (∼19–20 Ma) restriction of the Mesopotamian Seaway. Concomitant changes in bulk sediment CaCO3, Sr/Ca, K/Al, Ti/Al, Zr/Al, and Si/Ti support a major humid climate transition and associated intensification of river systems over western North Africa. We propose that these changes in North African hydroclimate reflect either a tipping point effect in a gradually warming global climate, or are the result of the initial restriction of the Mesopotamian Seaway, perhaps through consequent changes in Atlantic Meridional Overturning Circulation and the West African Monsoon. We also suggest the restriction of the Mesopotamian Seaway inhibited phosphorite deposition at low latitudes. |
URI: | https://www.um.edu.mt/library/oar/handle/123456789/102699 |
Appears in Collections: | Scholarly Works - FacEduMSE |
Files in This Item:
File | Description | Size | Format | |
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Early Miocene intensification of the North African hydrological cycle multi proxy evidence from the shelf carbonates of Malta 2022.pdf | 4.57 MB | Adobe PDF | View/Open |
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