Palaeoecology and palaeoenvironment of Mississippian coastal lakes and marshes during the early terrestrialisation of tetrapods
Palaeoecology and palaeoenvironment of Mississippian coastal lakes and marshes during the early terrestrialisation of tetrapods
The Ballagan Formation of northern Britain provides an exceptional record of Early Mississippian ecosystems that developed as tetrapods emerged onto land. In this paper, we study two 500-metre sections of the formation near Berwick-upon-Tweed, which are characterised by abundant ferroan dolostone beds. Five lithofacies are identified: cemented siltstone and sandstone, homogeneous dolomicrite, mixed dolomite and siltstone, mixed calcite and dolomite, and dolomite with evaporite minerals. Cemented sediments have non-planar to planar subhedral dolomite crystals, up to 40 μm in size, whereas other facies predominantly comprise dolomicrite or planar euhedral dolomite rhombs 15 μm in size, with patches of larger rhombs indicating partial recrystallisation. The macro- and microfossil content of the dolostones is dominated by sarcopterygian (rhizodont) and actinopterygian fish, bivalves, Serpula, ostracods and Chondrites trace fossils; with rarer Spirorbis, chondrichthyans (Ageleodus, hybodonts and ?ctenacanths, xenacanths), non-gyracanth acanthodians, gastropods, eurypterids, brachiopods, plant debris, wood, lycopsid roots, charcoal, megaspores, phycosiphoniform burrows, Zoophycos? and Rhizocorallium. The oxygen and carbon isotope composition of dolomites range from –3.6‰ to –1.7‰ (for δ18O) and –2.6‰ to +1.6‰ (for δ13C) respectively indicating dolomite growth in mixed salinity waters. Frequent marine storm-surge events transported marine waters and animals into floodplain lakes, where evaporation, interstitial sulphate-reducing bacteria, iron reduction and methanogenesis allowed dolomite growth in the shallow sub-surface. Secondary pedogenic modification (by roots, brecciation, desiccation, and soil forming processes) is common and represents lake evaporation with, in some cases, saline marsh development. The dolostone facies are part of a complex environmental mosaic of sub-aerial dry floodplain, wet marshy floodplains, rivers, and lakes ranging in salinity from freshwater to hypersaline. Marine influence is strongest at the base of the formation and decreases over time, as the floodplain became drier, and forested areas became more established. Coastal lakes were an important habitat for animals recovering from the end-Devonian Hangenberg Crisis and may have acted as a pathway for euryhaline fishes, molluscs and arthropods to access freshwater environments.
Carboniferous, Dolostone, Floodplain, Hypersaline, Lake, Tetrapods
Bennett, C.E.
e1684f72-df39-4d08-8321-f5d512f66727
Kearsey, T.I.
d81e2518-1290-4c61-87ed-e6f0d4b8e7c1
Davies, S.J.
90bb411e-4ba9-4f7c-88e7-2013dbc11bbf
Leng, M.J.
71755042-2b5f-44a6-8420-019f13a4a946
Millward, D.
7ddbec3f-6ba0-4345-8608-d60706ac8b7f
Smithson, T.R.
1f34d9ca-d0ee-44d7-876e-b167fef8e811
Brand, P.J.
51d43410-f9dd-4b95-b698-f9f424e35294
Browne, M.A.E.
90fdd1fa-bf6e-45c7-94a6-219002ddd507
Carpenter, D.K.
7e85c586-af81-4a0d-bcd1-27cd4a5187f2
Marshall, J.E.A.
cba178e3-91aa-49a2-b2ce-4b8d9d870b06
Dulson, H.
eff07265-8c28-49f4-a450-9707255c65ed
Curry, L.
28ae7b61-70d6-4ff8-91fa-a605dbfd9d52
15 February 2021
Bennett, C.E.
e1684f72-df39-4d08-8321-f5d512f66727
Kearsey, T.I.
d81e2518-1290-4c61-87ed-e6f0d4b8e7c1
Davies, S.J.
90bb411e-4ba9-4f7c-88e7-2013dbc11bbf
Leng, M.J.
71755042-2b5f-44a6-8420-019f13a4a946
Millward, D.
7ddbec3f-6ba0-4345-8608-d60706ac8b7f
Smithson, T.R.
1f34d9ca-d0ee-44d7-876e-b167fef8e811
Brand, P.J.
51d43410-f9dd-4b95-b698-f9f424e35294
Browne, M.A.E.
90fdd1fa-bf6e-45c7-94a6-219002ddd507
Carpenter, D.K.
7e85c586-af81-4a0d-bcd1-27cd4a5187f2
Marshall, J.E.A.
cba178e3-91aa-49a2-b2ce-4b8d9d870b06
Dulson, H.
eff07265-8c28-49f4-a450-9707255c65ed
Curry, L.
28ae7b61-70d6-4ff8-91fa-a605dbfd9d52
Bennett, C.E., Kearsey, T.I., Davies, S.J., Leng, M.J., Millward, D., Smithson, T.R., Brand, P.J., Browne, M.A.E., Carpenter, D.K., Marshall, J.E.A., Dulson, H. and Curry, L.
(2021)
Palaeoecology and palaeoenvironment of Mississippian coastal lakes and marshes during the early terrestrialisation of tetrapods.
Palaeogeography, Palaeoclimatology, Palaeoecology, 564, [110194].
(doi:10.1016/j.palaeo.2020.110194).
Abstract
The Ballagan Formation of northern Britain provides an exceptional record of Early Mississippian ecosystems that developed as tetrapods emerged onto land. In this paper, we study two 500-metre sections of the formation near Berwick-upon-Tweed, which are characterised by abundant ferroan dolostone beds. Five lithofacies are identified: cemented siltstone and sandstone, homogeneous dolomicrite, mixed dolomite and siltstone, mixed calcite and dolomite, and dolomite with evaporite minerals. Cemented sediments have non-planar to planar subhedral dolomite crystals, up to 40 μm in size, whereas other facies predominantly comprise dolomicrite or planar euhedral dolomite rhombs 15 μm in size, with patches of larger rhombs indicating partial recrystallisation. The macro- and microfossil content of the dolostones is dominated by sarcopterygian (rhizodont) and actinopterygian fish, bivalves, Serpula, ostracods and Chondrites trace fossils; with rarer Spirorbis, chondrichthyans (Ageleodus, hybodonts and ?ctenacanths, xenacanths), non-gyracanth acanthodians, gastropods, eurypterids, brachiopods, plant debris, wood, lycopsid roots, charcoal, megaspores, phycosiphoniform burrows, Zoophycos? and Rhizocorallium. The oxygen and carbon isotope composition of dolomites range from –3.6‰ to –1.7‰ (for δ18O) and –2.6‰ to +1.6‰ (for δ13C) respectively indicating dolomite growth in mixed salinity waters. Frequent marine storm-surge events transported marine waters and animals into floodplain lakes, where evaporation, interstitial sulphate-reducing bacteria, iron reduction and methanogenesis allowed dolomite growth in the shallow sub-surface. Secondary pedogenic modification (by roots, brecciation, desiccation, and soil forming processes) is common and represents lake evaporation with, in some cases, saline marsh development. The dolostone facies are part of a complex environmental mosaic of sub-aerial dry floodplain, wet marshy floodplains, rivers, and lakes ranging in salinity from freshwater to hypersaline. Marine influence is strongest at the base of the formation and decreases over time, as the floodplain became drier, and forested areas became more established. Coastal lakes were an important habitat for animals recovering from the end-Devonian Hangenberg Crisis and may have acted as a pathway for euryhaline fishes, molluscs and arthropods to access freshwater environments.
Text
Bennett et al_Miss coastal lakes_MS_Revised2 for PURE
- Accepted Manuscript
More information
Accepted/In Press date: 20 December 2020
e-pub ahead of print date: 27 December 2020
Published date: 15 February 2021
Additional Information:
Funding Information:
This study is a contribution to the TW:eed Project (Tetrapod World: early evolution and diversification), a major research programme investigating the rebuilding of Carboniferous ecosystems following a mass extinction at the end of the Devonian. This study was funded by NERC Consortium Grant ‘The Mid-Palaeozoic biotic crisis: setting the trajectory of tetrapod evolution’, led by the late Prof. Jenny Clack (University Museum of Zoology, Cambridge) and involving the universities of Leicester ( NE/J020729/1 ) and Southampton ( NE/J021091/1 ), the British Geological Survey ( NE/J021067/1 ) and the National Museum of Scotland . Jenny Clack took a great interest in all aspects of the TW:eed Project and is thanked for comments on a draft of the manuscript. We thank Anne Brown and Colin MacFadyan at NatureScot and Paul Bancks from Crown Estate Scotland for permission to collect from the foreshore at Burnmouth. The Norham cores are archived in the National Geological Repository at BGS, Keyworth. The support of staff in curation and facilitating access is acknowledged. The following TW:eed Project volunteers are thanks for their assistance with fossil identification from dolostone beds: Catherine Caseman, Rachel Curtis, Daniel Downs, Graham Liddiard, Jessica Mason, James Mawson and Kirsty Summers. We thank Mike Turner for allowing the use of dolostone isotope data from his PhD thesis. TIK, DM, MAEB, PJB and MJL publish with the permission of the Executive Director, British Geological Survey. Julian Andrews, Paul Wright and an anonymous reviewer are thanked for their insightful comments on this manuscript.
Funding Information:
This study is a contribution to the TW:eed Project (Tetrapod World: early evolution and diversification), a major research programme investigating the rebuilding of Carboniferous ecosystems following a mass extinction at the end of the Devonian. This study was funded by NERC Consortium Grant ?The Mid-Palaeozoic biotic crisis: setting the trajectory of tetrapod evolution?, led by the late Prof. Jenny Clack (University Museum of Zoology, Cambridge) and involving the universities of Leicester (NE/J020729/1) and Southampton (NE/J021091/1), the British Geological Survey (NE/J021067/1) and the National Museum of Scotland. Jenny Clack took a great interest in all aspects of the TW:eed Project and is thanked for comments on a draft of the manuscript. We thank Anne Brown and Colin MacFadyan at NatureScot and Paul Bancks from Crown Estate Scotland for permission to collect from the foreshore at Burnmouth. The Norham cores are archived in the National Geological Repository at BGS, Keyworth. The support of staff in curation and facilitating access is acknowledged. The following TW:eed Project volunteers are thanks for their assistance with fossil identification from dolostone beds: Catherine Caseman, Rachel Curtis, Daniel Downs, Graham Liddiard, Jessica Mason, James Mawson and Kirsty Summers. We thank Mike Turner for allowing the use of dolostone isotope data from his PhD thesis. TIK, DM, MAEB, PJB and MJL publish with the permission of the Executive Director, British Geological Survey. Julian Andrews, Paul Wright and an anonymous reviewer are thanked for their insightful comments on this manuscript.
Publisher Copyright:
© 2020
Keywords:
Carboniferous, Dolostone, Floodplain, Hypersaline, Lake, Tetrapods
Identifiers
Local EPrints ID: 446084
URI: http://eprints.soton.ac.uk/id/eprint/446084
ISSN: 0031-0182
PURE UUID: 1320123d-a572-40b0-98fd-2e692fd3633e
Catalogue record
Date deposited: 20 Jan 2021 17:31
Last modified: 17 Mar 2024 06:15
Export record
Altmetrics
Contributors
Author:
C.E. Bennett
Author:
T.I. Kearsey
Author:
S.J. Davies
Author:
M.J. Leng
Author:
D. Millward
Author:
T.R. Smithson
Author:
P.J. Brand
Author:
M.A.E. Browne
Author:
D.K. Carpenter
Author:
H. Dulson
Author:
L. Curry
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
