Dating basal peat: The geochronology of peat initiation revisited

Cindy Quik; Sanne W.L. Palstra; Roy van Beek; Ype van der Velde; Jasper H.J. Candel; Marjolein van der Linden; Lucy Kubiak-Martens; Graeme T. Swindles; Bart Makaske; Jakob Wallinga

doi:10.1016/j.quageo.2022.101278

Dating basal peat: The geochronology of peat initiation revisited

Cindy Quik^*, Sanne W.L. Palstra, Roy van Beek, Ype van der Velde, Jasper H.J. Candel, Marjolein van der Linden, Lucy Kubiak-Martens, Graeme T. Swindles, Bart Makaske, Jakob Wallinga

^*Corresponding author for this work

Earth and Climate

Research output: Contribution to Journal › Article › Academic › peer-review

Abstract

Attributing the start of peat growth to an absolute timescale requires dating the bottom of peat deposits overlying mineral sediment, often called the basal peat. Peat initiation is reflected in the stratigraphy as a gradual transition from mineral sediment to increasingly organic material, up to where it is called peat. So far, varying criteria have been used to define basal peat, resulting in divergent approaches to date peat initiation. The lack of a universally applicable and quantitative definition, combined with multiple concerns that have been raised previously regarding the radiocarbon dating of peat, may result in apparent ages that are either too old or too young for the timing of peat initiation. Here, we aim to formulate updated recommendations for dating peat initiation. We provide a conceptual framework that supports the use of the organic matter (OM) gradient for a quantitative and reproducible definition of the mineral-to-peat transition (i.e., the stratigraphical range reflecting the timespan of the peat initiation process) and the layer defined as basal peat (i.e., the stratigraphical layer that is defined as the bottom of a peat deposit). Selection of dating samples is often challenging due to poor preservation of plant macrofossils in basal peat, and the representativity of humic and humin dates for the age of basal peat is uncertain. We therefore analyse the mineral-to-peat transition based on three highly detailed sequences of radiocarbon dates, including dates of plant macrofossils and the humic and humin fractions obtained from bulk samples. Our case study peatland in the Netherlands currently harbours a bog vegetation, but biostratigraphical analyses show that during peat initiation the vegetation was mesotrophic. Results show that plant macrofossils provide the most accurate age in the mineral-to-peat transition and are therefore recommendable to use for ¹⁴C dating basal peat. If these are unattainable, the humic fraction provides the best alternative and is interpreted as a terminus-ante-quem for peat initiation. The potential large age difference between dates of plant macrofossils and humic or humin dates (up to ∼1700 years between macrofossil and humic ages, and with even larger differences for humins) suggests that studies reusing existing bulk dates of basal peat should take great care in data interpretation. The potentially long timespan of the peat initiation process (with medians of ∼1000, ∼1300 and ∼1500 years within our case study peatland) demonstrates that choices regarding sampling size and resolution need to be well substantiated. We summarise our findings as a set of recommendations for dating basal peats, and advocate the widespread use of OM determination to obtain a low-cost, quantitative and reproducible definition of basal peat that eases intercomparison of studies.

Original language	English
Article number	101278
Pages (from-to)	1-22
Number of pages	22
Journal	Quaternary Geochronology
Volume	72
Early online date	26 Mar 2022
DOIs	https://doi.org/10.1016/j.quageo.2022.101278
Publication status	Published - Aug 2022

Bibliographical note

Funding Information:
This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research (NWO) under grant number: 276-60-003. We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochteloërveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated.

Funding Information:
This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research ( NWO ) under grant number: 276-60-003 . We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochteloërveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated.

Publisher Copyright:
© 2022 The Authors

Keywords

Accelerator mass spectrometry (AMS)
Bulk
Humics
Humins
Organic matter
Peat initiation
Peat remnant
Plant macrofossils
Radiocarbon
Stratigraphy

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.quageo.2022.101278

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Cite this

@article{0526cf7405b94d30b31c9012c1eb4ee1,

title = "Dating basal peat: The geochronology of peat initiation revisited",

abstract = "Attributing the start of peat growth to an absolute timescale requires dating the bottom of peat deposits overlying mineral sediment, often called the basal peat. Peat initiation is reflected in the stratigraphy as a gradual transition from mineral sediment to increasingly organic material, up to where it is called peat. So far, varying criteria have been used to define basal peat, resulting in divergent approaches to date peat initiation. The lack of a universally applicable and quantitative definition, combined with multiple concerns that have been raised previously regarding the radiocarbon dating of peat, may result in apparent ages that are either too old or too young for the timing of peat initiation. Here, we aim to formulate updated recommendations for dating peat initiation. We provide a conceptual framework that supports the use of the organic matter (OM) gradient for a quantitative and reproducible definition of the mineral-to-peat transition (i.e., the stratigraphical range reflecting the timespan of the peat initiation process) and the layer defined as basal peat (i.e., the stratigraphical layer that is defined as the bottom of a peat deposit). Selection of dating samples is often challenging due to poor preservation of plant macrofossils in basal peat, and the representativity of humic and humin dates for the age of basal peat is uncertain. We therefore analyse the mineral-to-peat transition based on three highly detailed sequences of radiocarbon dates, including dates of plant macrofossils and the humic and humin fractions obtained from bulk samples. Our case study peatland in the Netherlands currently harbours a bog vegetation, but biostratigraphical analyses show that during peat initiation the vegetation was mesotrophic. Results show that plant macrofossils provide the most accurate age in the mineral-to-peat transition and are therefore recommendable to use for 14C dating basal peat. If these are unattainable, the humic fraction provides the best alternative and is interpreted as a terminus-ante-quem for peat initiation. The potential large age difference between dates of plant macrofossils and humic or humin dates (up to ∼1700 years between macrofossil and humic ages, and with even larger differences for humins) suggests that studies reusing existing bulk dates of basal peat should take great care in data interpretation. The potentially long timespan of the peat initiation process (with medians of ∼1000, ∼1300 and ∼1500 years within our case study peatland) demonstrates that choices regarding sampling size and resolution need to be well substantiated. We summarise our findings as a set of recommendations for dating basal peats, and advocate the widespread use of OM determination to obtain a low-cost, quantitative and reproducible definition of basal peat that eases intercomparison of studies.",

keywords = "Accelerator mass spectrometry (AMS), Bulk, Humics, Humins, Organic matter, Peat initiation, Peat remnant, Plant macrofossils, Radiocarbon, Stratigraphy",

author = "Cindy Quik and Palstra, {Sanne W.L.} and {van Beek}, Roy and {van der Velde}, Ype and Candel, {Jasper H.J.} and {van der Linden}, Marjolein and Lucy Kubiak-Martens and Swindles, {Graeme T.} and Bart Makaske and Jakob Wallinga",

note = "Funding Information: This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research (NWO) under grant number: 276-60-003. We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochtelo{\"e}rveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated. Funding Information: This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research ( NWO ) under grant number: 276-60-003 . We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochtelo{\"e}rveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated. Publisher Copyright: {\textcopyright} 2022 The Authors",

year = "2022",

month = aug,

doi = "10.1016/j.quageo.2022.101278",

language = "English",

volume = "72",

pages = "1--22",

journal = "Quaternary Geochronology",

issn = "1871-1014",

publisher = "Elsevier",

}

TY - JOUR

T1 - Dating basal peat

T2 - The geochronology of peat initiation revisited

AU - Quik, Cindy

AU - Palstra, Sanne W.L.

AU - van Beek, Roy

AU - van der Velde, Ype

AU - Candel, Jasper H.J.

AU - van der Linden, Marjolein

AU - Kubiak-Martens, Lucy

AU - Swindles, Graeme T.

AU - Makaske, Bart

AU - Wallinga, Jakob

N1 - Funding Information: This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research (NWO) under grant number: 276-60-003. We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochteloërveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated. Funding Information: This research is part of the research programme Home Turf - An integrated approach to Dutch raised bogs, funded by the Netherlands Organization for Scientific Research ( NWO ) under grant number: 276-60-003 . We thank Roos Veeneklaas (Natuurmonumenten Noordenveld) for permission to do fieldwork at the Fochteloërveen and for sharing detailed field knowledge; Hans Beens (Staatsbosbeheer Kop van Drenthe) for providing access to private roads to be able to reach the field sites; Teun Fiers, Klais Blaauw, Tom Harkema, Marte Stoorvogel, and Gibran Leeflang for field assistance; Mieke Hannink for administrative assistance with organising the fieldwork; Marcello Novani (Laboratory for Geo-information Science, WUR) for providing GNSS equipment; Jim Quik for construction work for core transport; Wouter van der Meer (BIAX Consult) for his help with opening and subsampling the cores; Harm Goorens for assistance with LOI analyses at the Soil Hydro Physics Lab (WUR) and Piet Peters for providing storage space in the cool room; Anne Roepert and colleagues of the CBLB for LOI analyses; Romy Koudijs for sharing OM data on the five duplicate cores; and Bas van Geel for his kind introduction to analysis of plant macrofossils. We thank Julie Loisel and an anonymous reviewer for their constructive comments to an earlier version of this manuscript; their feedback was much appreciated. Publisher Copyright: © 2022 The Authors

PY - 2022/8

Y1 - 2022/8

N2 - Attributing the start of peat growth to an absolute timescale requires dating the bottom of peat deposits overlying mineral sediment, often called the basal peat. Peat initiation is reflected in the stratigraphy as a gradual transition from mineral sediment to increasingly organic material, up to where it is called peat. So far, varying criteria have been used to define basal peat, resulting in divergent approaches to date peat initiation. The lack of a universally applicable and quantitative definition, combined with multiple concerns that have been raised previously regarding the radiocarbon dating of peat, may result in apparent ages that are either too old or too young for the timing of peat initiation. Here, we aim to formulate updated recommendations for dating peat initiation. We provide a conceptual framework that supports the use of the organic matter (OM) gradient for a quantitative and reproducible definition of the mineral-to-peat transition (i.e., the stratigraphical range reflecting the timespan of the peat initiation process) and the layer defined as basal peat (i.e., the stratigraphical layer that is defined as the bottom of a peat deposit). Selection of dating samples is often challenging due to poor preservation of plant macrofossils in basal peat, and the representativity of humic and humin dates for the age of basal peat is uncertain. We therefore analyse the mineral-to-peat transition based on three highly detailed sequences of radiocarbon dates, including dates of plant macrofossils and the humic and humin fractions obtained from bulk samples. Our case study peatland in the Netherlands currently harbours a bog vegetation, but biostratigraphical analyses show that during peat initiation the vegetation was mesotrophic. Results show that plant macrofossils provide the most accurate age in the mineral-to-peat transition and are therefore recommendable to use for 14C dating basal peat. If these are unattainable, the humic fraction provides the best alternative and is interpreted as a terminus-ante-quem for peat initiation. The potential large age difference between dates of plant macrofossils and humic or humin dates (up to ∼1700 years between macrofossil and humic ages, and with even larger differences for humins) suggests that studies reusing existing bulk dates of basal peat should take great care in data interpretation. The potentially long timespan of the peat initiation process (with medians of ∼1000, ∼1300 and ∼1500 years within our case study peatland) demonstrates that choices regarding sampling size and resolution need to be well substantiated. We summarise our findings as a set of recommendations for dating basal peats, and advocate the widespread use of OM determination to obtain a low-cost, quantitative and reproducible definition of basal peat that eases intercomparison of studies.

AB - Attributing the start of peat growth to an absolute timescale requires dating the bottom of peat deposits overlying mineral sediment, often called the basal peat. Peat initiation is reflected in the stratigraphy as a gradual transition from mineral sediment to increasingly organic material, up to where it is called peat. So far, varying criteria have been used to define basal peat, resulting in divergent approaches to date peat initiation. The lack of a universally applicable and quantitative definition, combined with multiple concerns that have been raised previously regarding the radiocarbon dating of peat, may result in apparent ages that are either too old or too young for the timing of peat initiation. Here, we aim to formulate updated recommendations for dating peat initiation. We provide a conceptual framework that supports the use of the organic matter (OM) gradient for a quantitative and reproducible definition of the mineral-to-peat transition (i.e., the stratigraphical range reflecting the timespan of the peat initiation process) and the layer defined as basal peat (i.e., the stratigraphical layer that is defined as the bottom of a peat deposit). Selection of dating samples is often challenging due to poor preservation of plant macrofossils in basal peat, and the representativity of humic and humin dates for the age of basal peat is uncertain. We therefore analyse the mineral-to-peat transition based on three highly detailed sequences of radiocarbon dates, including dates of plant macrofossils and the humic and humin fractions obtained from bulk samples. Our case study peatland in the Netherlands currently harbours a bog vegetation, but biostratigraphical analyses show that during peat initiation the vegetation was mesotrophic. Results show that plant macrofossils provide the most accurate age in the mineral-to-peat transition and are therefore recommendable to use for 14C dating basal peat. If these are unattainable, the humic fraction provides the best alternative and is interpreted as a terminus-ante-quem for peat initiation. The potential large age difference between dates of plant macrofossils and humic or humin dates (up to ∼1700 years between macrofossil and humic ages, and with even larger differences for humins) suggests that studies reusing existing bulk dates of basal peat should take great care in data interpretation. The potentially long timespan of the peat initiation process (with medians of ∼1000, ∼1300 and ∼1500 years within our case study peatland) demonstrates that choices regarding sampling size and resolution need to be well substantiated. We summarise our findings as a set of recommendations for dating basal peats, and advocate the widespread use of OM determination to obtain a low-cost, quantitative and reproducible definition of basal peat that eases intercomparison of studies.

KW - Accelerator mass spectrometry (AMS)

KW - Bulk

KW - Humics

KW - Humins

KW - Organic matter

KW - Peat initiation

KW - Peat remnant

KW - Plant macrofossils

KW - Radiocarbon

KW - Stratigraphy

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VL - 72

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JF - Quaternary Geochronology

M1 - 101278

ER -

Dating basal peat: The geochronology of peat initiation revisited

Abstract

Bibliographical note

Keywords

UN SDGs

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Data from: Dating basal peat: The geochronology of peat initiation revisited

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Dating basal peat: The geochronology of peat initiation revisited

Abstract

Bibliographical note

Keywords

UN SDGs

Access to Document

Persistent URL (handle)

Other files and links

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Data from: Dating basal peat: The geochronology of peat initiation revisited

Data from: Dating basal peat: The geochronology of peat initiation revisited

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