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Álvaro JJ, Holmer LE, Shen Y, Popov LE, Ghobadi Pour M, Zhang Z, Zhang Z, Ahlberg P, Bauert H, González-Acebrón L. Submarine metalliferous carbonate mounds in the Cambrian of the Baltoscandian Basin induced by vent networks and water column stratification. Sci Rep 2022; 12:8475. [PMID: 35589924 PMCID: PMC9119982 DOI: 10.1038/s41598-022-12379-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 04/13/2022] [Indexed: 11/30/2022] Open
Abstract
Two massive precipitation events of polymetallic ore deposits, encrusted by a mixture of authigenic carbonates, are documented from the Cambrian of the semi-enclosed Baltoscandian Basin. δ34S (‒9.33 to ‒2.08‰) and δ33S (‒4.75 to ‒1.06‰) values from the basal sulphide breccias, sourced from contemporaneous Pb–Zn–Fe-bearing vein stockworks, reflect sulphide derived from both microbial and abiotic sulphate reduction. Submarine metalliferous deposits were triggered by non-buoyant hydrothermal plumes: plumes of buoyant fluid were trapped by water column stratification because their buoyancy with respect to the environment reversed, fluids became heavier than their surroundings and gravitational forces brought them to a halt, spreading out laterally from originating vents and resulting in the lateral dispersion of effluents and sulphide particle settling. Subsequently, polymetallic exhalites were sealed by carbonate crusts displaying three generations of ikaite-to-aragonite palisade crystals, now recrystallized to calcite and subsidiary vaterite. Th of fluid inclusions in early calcite crystals, ranging from 65 to 78 ºC, provide minimum entrapment temperatures for carbonate precipitation and early recrystallization. δ13Ccarb (‒1.1 to + 1.6‰) and δ18Ocarb (‒7.6 to ‒6.5‰) values are higher than those preserved in contemporaneous glendonite concretions (‒8.5 to ‒4.7‰ and ‒12.4 to ‒9.1‰, respectively) embedded in kerogenous shales, the latter related to thermal degradation of organic matter. Hydrothermal discharges graded from highly reduced, acidic, metalliferous, and hot (~ 150 ºC) to slightly alkaline, calcium-rich and warm (< 100 ºC), controlling the precipitation of authigenic carbonates.
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Affiliation(s)
- J Javier Álvaro
- Instituto de Geociencias (CSIC-UCM), Dr. Severo Ochoa 7, 28040, Madrid, Spain.
| | - Lars E Holmer
- Department of Earth Sciences, Palaeobiology, Uppsala University, 75236, Uppsala, Sweden.,State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an, 710069, China
| | - Yanan Shen
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Leonid E Popov
- Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff, CF10 3NP, UK
| | - Mansoureh Ghobadi Pour
- Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff, CF10 3NP, UK.,Department of Geology, Faculty of Sciences, Golestan University, Gorgan, 49138-15739, Iran
| | - Zhifei Zhang
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an, 710069, China
| | - Zhiliang Zhang
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an, 710069, China
| | - Per Ahlberg
- Department of Geology, Lund University, Sölvegatan 12, 22362, Lund, Sweden
| | - Heikki Bauert
- Geological Survey of Estonia, Tartu maantee 85, 11412, Tallinn, Estonia
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Vickers ML, Lengger SK, Bernasconi SM, Thibault N, Schultz BP, Fernandez A, Ullmann CV, McCormack P, Bjerrum CJ, Rasmussen JA, Hougård IW, Korte C. Cold spells in the Nordic Seas during the early Eocene Greenhouse. Nat Commun 2020; 11:4713. [PMID: 32948769 PMCID: PMC7501286 DOI: 10.1038/s41467-020-18558-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 08/21/2020] [Indexed: 11/18/2022] Open
Abstract
The early Eocene (c. 56 - 48 million years ago) experienced some of the highest global temperatures in Earth’s history since the Mesozoic, with no polar ice. Reports of contradictory ice-rafted erratics and cold water glendonites in the higher latitudes have been largely dismissed due to ambiguity of the significance of these purported cold-climate indicators. Here we apply clumped isotope paleothermometry to a traditionally qualitative abiotic proxy, glendonite calcite, to generate quantitative temperature estimates for northern mid-latitude bottom waters. Our data show that the glendonites of the Danish Basin formed in waters below 5 °C, at water depths of <300 m. Such near-freezing temperatures have not previously been reconstructed from proxy data for anywhere on the early Eocene Earth, and these data therefore suggest that regionalised cool episodes punctuated the background warmth of the early Eocene, likely linked to eruptive phases of the North Atlantic Igneous Province. The early Eocene was characterized by exceptionally high global temperatures and no polar ice. Here, clumped isotope paleothermometry of glendonite calcite from the Danish Basin shows that these were formed in waters below 5 °C, indicating that regionalised cool episodes punctuated the background warmth of the early Eocene.
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Affiliation(s)
- Madeleine L Vickers
- IGN, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark.
| | - Sabine K Lengger
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | | | - Nicolas Thibault
- IGN, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | | | - Alvaro Fernandez
- Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Allégaten 41, N-5007, Bergen, Norway
| | - Clemens V Ullmann
- Camborne School of Mines, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Paul McCormack
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | - Christian J Bjerrum
- IGN, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
| | - Jan Audun Rasmussen
- Museum Mors, Fossil- and Mo-clay Museum, Skarrehagevej 8, 7900, Nykøbing Mors, Denmark
| | | | - Christoph Korte
- IGN, University of Copenhagen, Øster Voldgade 10, DK-1350, Copenhagen, Denmark
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