Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta
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 at...
Published in: | Paleoceanography and Paleoclimatology |
---|---|
Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2022
|
Subjects: | |
Online Access: | https://orca.cardiff.ac.uk/id/eprint/152856/ https://doi.org/10.1029/2022pa004414 https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf |
id |
ftunivcardiff:oai:https://orca.cardiff.ac.uk:152856 |
---|---|
record_format |
openpolar |
spelling |
ftunivcardiff:oai:https://orca.cardiff.ac.uk:152856 2023-05-15T13:49:12+02:00 Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta Zammit, R. Lear, C. H. Samankassou, E. Lourens, L. J. Micallef, A. Pearson, P. N. Bialik, O. M. 2022-09-13 application/pdf https://orca.cardiff.ac.uk/id/eprint/152856/ https://doi.org/10.1029/2022pa004414 https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf en eng American Geophysical Union https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf Zammit, R. https://orca.cardiff.ac.uk/view/cardiffauthors/A21875706.html, Lear, C. H. https://orca.cardiff.ac.uk/view/cardiffauthors/A048848V.html orcid:0000-0002-7533-4430 orcid:0000-0002-7533-4430, Samankassou, E., Lourens, L. J., Micallef, A., Pearson, P. N. https://orca.cardiff.ac.uk/view/cardiffauthors/A0179150.html orcid:0000-0003-4628-9818 orcid:0000-0003-4628-9818 and 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 37 (9) , e2022PA004414. 10.1029/2022pa004414 https://doi.org/10.1029/2022pa004414 file https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf doi:10.1029/2022pa004414 cc_by_4_0 CC-BY Article PeerReviewed 2022 ftunivcardiff https://doi.org/10.1029/2022pa004414 2022-12-01T23:35:30Z 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. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Cardiff University: ORCA (Online Research @ Cardiff) Antarctic Paleoceanography and Paleoclimatology 37 9 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
description |
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. |
format |
Article in Journal/Newspaper |
author |
Zammit, R. Lear, C. H. Samankassou, E. Lourens, L. J. Micallef, A. Pearson, P. N. Bialik, O. M. |
spellingShingle |
Zammit, R. Lear, C. H. Samankassou, E. Lourens, L. J. Micallef, A. Pearson, P. N. Bialik, O. M. Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
author_facet |
Zammit, R. Lear, C. H. Samankassou, E. Lourens, L. J. Micallef, A. Pearson, P. N. Bialik, O. M. |
author_sort |
Zammit, R. |
title |
Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
title_short |
Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
title_full |
Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
title_fullStr |
Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
title_full_unstemmed |
Early Miocene intensification of the North African hydrological cycle: multi‐proxy evidence from the shelf carbonates of Malta |
title_sort |
early miocene intensification of the north african hydrological cycle: multi‐proxy evidence from the shelf carbonates of malta |
publisher |
American Geophysical Union |
publishDate |
2022 |
url |
https://orca.cardiff.ac.uk/id/eprint/152856/ https://doi.org/10.1029/2022pa004414 https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf Zammit, R. https://orca.cardiff.ac.uk/view/cardiffauthors/A21875706.html, Lear, C. H. https://orca.cardiff.ac.uk/view/cardiffauthors/A048848V.html orcid:0000-0002-7533-4430 orcid:0000-0002-7533-4430, Samankassou, E., Lourens, L. J., Micallef, A., Pearson, P. N. https://orca.cardiff.ac.uk/view/cardiffauthors/A0179150.html orcid:0000-0003-4628-9818 orcid:0000-0003-4628-9818 and 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 37 (9) , e2022PA004414. 10.1029/2022pa004414 https://doi.org/10.1029/2022pa004414 file https://orca.cardiff.ac.uk/id/eprint/152856/1/2022PA004414.pdf doi:10.1029/2022pa004414 |
op_rights |
cc_by_4_0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2022pa004414 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
9 |
_version_ |
1766250989914947584 |