North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback
The Paleogene history of biogenic opal accumulation in the North Atlantic provides insight into both the evolution of deep-water circulation in the Atlantic basin, and weathering responses to major climate shifts. However, existing records are compromised by low temporal resolution and/or stratigrap...
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ftucl:oai:eprints.ucl.ac.uk.OAI2:10127741 2023-12-24T10:17:15+01:00 North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback Witkowski, J Bryłka, K Bohaty, SM Mydłowska, E Penman, DE Wade, B 2021-05-12 text https://discovery.ucl.ac.uk/id/eprint/10127741/1/Witkowski%20et%20al%20CPD.pdf https://discovery.ucl.ac.uk/id/eprint/10127741/ eng eng Copernicus Publications https://discovery.ucl.ac.uk/id/eprint/10127741/1/Witkowski%20et%20al%20CPD.pdf https://discovery.ucl.ac.uk/id/eprint/10127741/ open (Climate of the Past: Discussions ). Copernicus Publications (2021) Working / discussion paper 2021 ftucl 2023-11-27T13:07:36Z The Paleogene history of biogenic opal accumulation in the North Atlantic provides insight into both the evolution of deep-water circulation in the Atlantic basin, and weathering responses to major climate shifts. However, existing records are compromised by low temporal resolution and/or stratigraphic discontinuities. In order to address this problem, we present a multi-site, high-resolution record of biogenic silica (bioSiO2) accumulation from Blake Nose (ODP Leg 171B, western North Atlantic) spanning the early Paleocene through late Eocene time interval (~65‒34 Ma). This record represents the longest single-locality history of marine bioSiO2 burial compiled to date and offers a unique perspective into changes in bioSiO2 fluxes through the early-to-mid Paleogene extreme greenhouse interval and subsequent period of long-term cooling. Blake Nose bioSiO2 fluxes display prominent fluctuations that we attribute to variations in sub-thermocline nutrient supply via cyclonic eddies associated with the Gulf Stream. Whereas few constraints are available on the bioSiO2 flux pulses peaking in the early Paleocene and early Eocene, a middle Eocene interval of elevated bioSiO2 flux between ~46 and 42 Ma is proposed to reflect nutrient enrichment due to invigorated overturning circulation following an early onset of Northern Component Water export from the Norwegian-Greenland Sea at ~49 Ma. Comparison of our North Atlantic record against published Pacific bioSiO2 flux records indicates a diminished nutrient supply to the Atlantic between ~42 and 38 Ma, interpreted as a response to weakening of the overturning circulation. Subsequently, a deep-water circulation regime favoring limited bioSiO2 burial in Atlantic and enhanced bioSiO2 burial in the Pacific was established after ~38 Ma, likely in association with a further invigoration of deep-water export from the North Atlantic. We also observe that Blake Nose bioSiO2 fluxes through the middle Eocene cooling interval (~48 to 34 Ma) are consistently higher than background fluxes ... Report Greenland Greenland Sea North Atlantic University College London: UCL Discovery Greenland Pacific |
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University College London: UCL Discovery |
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ftucl |
language |
English |
description |
The Paleogene history of biogenic opal accumulation in the North Atlantic provides insight into both the evolution of deep-water circulation in the Atlantic basin, and weathering responses to major climate shifts. However, existing records are compromised by low temporal resolution and/or stratigraphic discontinuities. In order to address this problem, we present a multi-site, high-resolution record of biogenic silica (bioSiO2) accumulation from Blake Nose (ODP Leg 171B, western North Atlantic) spanning the early Paleocene through late Eocene time interval (~65‒34 Ma). This record represents the longest single-locality history of marine bioSiO2 burial compiled to date and offers a unique perspective into changes in bioSiO2 fluxes through the early-to-mid Paleogene extreme greenhouse interval and subsequent period of long-term cooling. Blake Nose bioSiO2 fluxes display prominent fluctuations that we attribute to variations in sub-thermocline nutrient supply via cyclonic eddies associated with the Gulf Stream. Whereas few constraints are available on the bioSiO2 flux pulses peaking in the early Paleocene and early Eocene, a middle Eocene interval of elevated bioSiO2 flux between ~46 and 42 Ma is proposed to reflect nutrient enrichment due to invigorated overturning circulation following an early onset of Northern Component Water export from the Norwegian-Greenland Sea at ~49 Ma. Comparison of our North Atlantic record against published Pacific bioSiO2 flux records indicates a diminished nutrient supply to the Atlantic between ~42 and 38 Ma, interpreted as a response to weakening of the overturning circulation. Subsequently, a deep-water circulation regime favoring limited bioSiO2 burial in Atlantic and enhanced bioSiO2 burial in the Pacific was established after ~38 Ma, likely in association with a further invigoration of deep-water export from the North Atlantic. We also observe that Blake Nose bioSiO2 fluxes through the middle Eocene cooling interval (~48 to 34 Ma) are consistently higher than background fluxes ... |
format |
Report |
author |
Witkowski, J Bryłka, K Bohaty, SM Mydłowska, E Penman, DE Wade, B |
spellingShingle |
Witkowski, J Bryłka, K Bohaty, SM Mydłowska, E Penman, DE Wade, B North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
author_facet |
Witkowski, J Bryłka, K Bohaty, SM Mydłowska, E Penman, DE Wade, B |
author_sort |
Witkowski, J |
title |
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
title_short |
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
title_full |
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
title_fullStr |
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
title_full_unstemmed |
North Atlantic marine biogenic silica accumulation through the early-to-mid Paleogene: implications for ocean circulation and silicate weathering feedback |
title_sort |
north atlantic marine biogenic silica accumulation through the early-to-mid paleogene: implications for ocean circulation and silicate weathering feedback |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://discovery.ucl.ac.uk/id/eprint/10127741/1/Witkowski%20et%20al%20CPD.pdf https://discovery.ucl.ac.uk/id/eprint/10127741/ |
geographic |
Greenland Pacific |
geographic_facet |
Greenland Pacific |
genre |
Greenland Greenland Sea North Atlantic |
genre_facet |
Greenland Greenland Sea North Atlantic |
op_source |
(Climate of the Past: Discussions ). Copernicus Publications (2021) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/10127741/1/Witkowski%20et%20al%20CPD.pdf https://discovery.ucl.ac.uk/id/eprint/10127741/ |
op_rights |
open |
_version_ |
1786205245495312384 |