Gamborg Fjord – XRONOS

Site types

Miscellaneous, settlement, and

Location

Coordinates (degrees): 055.453° N, 009.776° E
Coordinates (DMS): 055° 27' 00" E, 009° 46' 00" N
Country (ISO 3166): Denmark (DK)

Lab ID	Context	Material	Taxon	Method	Uncalibrated age	Calibrated age	References
K-5731		wood	NA	14C	5280±90 BP	6280–5903 cal BP	Weninger 2022
K-6778		shell	Ostrea	14C	5440±75 BP	6394–6002 cal BP	Hinz et al. 2012 Weninger 2022
K-6779		wood	NA	14C	5190±90 BP	6198–5730 cal BP	Hinz et al. 2012 Weninger 2022
K-6780		wood	NA	14C	5210±65 BP	6188–5758 cal BP	Hinz et al. 2012 Weninger 2022
K-6779	From sandy gytja (mud) layer.	wood	Wood (Alnus, Corylus, Quercus, Tilia, Ulmus and unknown).	NA	5190±90 BP	6198–5730 cal BP	AUD 1997, 373 Hinz et al. 2012
K-6780	From sandy gytja (mud) layer.	wood	Wood (Coylus, Quercus, Tilia and mud)	NA	5210±65 BP	6188–5758 cal BP	AUD 1997, 373 Hinz et al. 2012
AAR-1011	Found 1,2 m below sealevel.	wood	Submerged 17 m tree-trunk.	NA	5190±130 BP	6275–5612 cal BP	AUD 1992, 300 Hinz et al. 2012
K-6778	Kitchen midding (Køkkenmødding)	shell	Oyster shells (Ostrea sp.).	NA	5440±75 BP	6394–6002 cal BP	AUD 1997, 273 Hinz et al. 2012
K-5731	Kitchen midding (Køkkenmødding)	shell	Shells (Ostrea ed.)	NA	5280±90 BP	6280–5903 cal BP	AUD 1991, 239 Hinz et al. 2012
AAR-969	wooden handle of unknown type.	wood	Wood (Ulmus sp.)	NA	5440±95 BP	6403–5994 cal BP	AUD 1992, 299 Hinz et al. 2012
K-5731	Kitchen midding (Køkkenmødding)	shell	Shells (Ostrea ed.)	NA	5280±90 BP	6280–5903 cal BP	AUD 1991, 239 Hinz et al. 2012
AAR-1011		wood	NA	NA	5190±130 BP	6275–5612 cal BP	AUD 1992 300 Bird et al. 2022
AAR-969		wood	NA	NA	5440±95 BP	6403–5994 cal BP	AUD 1992 299 Bird et al. 2022
K-6778		shell	NA	NA	5440±75 BP	6394–6002 cal BP	AUD 1997 273 Bird et al. 2022
K-6779		wood	NA	NA	5190±90 BP	6198–5730 cal BP	AUD 1997 373 Bird et al. 2022
K-6780		wood	NA	NA	5210±65 BP	6188–5758 cal BP	AUD 1997 373 Bird et al. 2022

Classification	Estimated age	References
Meso/Neo	NA	Hinz et al. 2012
Ertebølle	NA	NA
Meso/Neo	NA	Hinz et al. 2012
Ertebølle	NA	NA
Meso/Neo	NA	Hinz et al. 2012
Ertebølle	NA	NA
späte	NA	AUD 1997, 373
Ertebølle-Ellerbek	NA	NA
Ertebølle-Ellerbek	NA	AUD 1997, 373
späte	NA	AUD 1997, 273
Ertebølle-Ellerbek	NA	NA
mittlere	NA	AUD 1991, 239
Ertebølle-Ellerbek	NA	NA
mittlere	NA	AUD 1991, 239
Ertebølle-Ellerbek	NA	NA

Bibliographic references

Hinz, M., Furholt, M., Müller, J., Raetzel-Fabian, D., Rinne, C., Sjögren, K.-G., & Wotzka, H.-P. (2012). RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age. Journal of Neolithic Archaeology, 14, 1–4. https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116 [RADON]
No bibliographic information available. [AUD 1997, 373]
No bibliographic information available. [AUD 1992, 300]
No bibliographic information available. [AUD 1997, 273]
No bibliographic information available. [AUD 1991, 239]
No bibliographic information available. [AUD 1992, 299]
No bibliographic information available. [AUD 1992 300]
No bibliographic information available. [AUD 1992 299]
No bibliographic information available. [AUD 1997 273]
No bibliographic information available. [AUD 1997 373]
Weninger, B. (2022). CalPal Edition 2022.9. Zenodo. https://doi.org/1010.5281/zenodo.7422618 [CalPal2022]
Hinz, M., Furholt, M., Müller, J., Raetzel-Fabian, D., Rinne, C., Sjögren, K.-G., & Wotzka, H.-P. (2012). RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age. Journal of Neolithic Archaeology, 14, 1–4. https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116 [RADON]
Bird, D., Miranda, L., Vander Linden, M., Robinson, E., Bocinsky, R. K., Nicholson, C., Capriles, J. M., Finley, J. B., Gayo, E. M., Gil, A., d’Alpoim Guedes, J., Hoggarth, J. A., Kay, A., Loftus, E., Lombardo, U., Mackie, M., Palmisano, A., Solheim, S., Kelly, R. L., & Freeman, J. (2022). P3k14c, a Synthetic Global Database of Archaeological Radiocarbon Dates. Scientific Data, 9(1), 27. https://doi.org/10.1038/s41597-022-01118-7 [p3k14c]

@article{RADON,
  title = {RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age.},
  author = {Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian, Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter},
  date = {2012},
  journaltitle = {Journal of Neolithic Archaeology},
  volume = {14},
  pages = {1–4},
  url = {https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116},
  abstract = {In order to understand the dynamics of cultural phenomena, scientific dating in archaeology is an increasingly indispensable tool. Only by dating independently of typology is it possible to understand typological development itself (Müller 2004). Here radiometric dating methods, especially those based on carbon isotopy, still play the most important role. For evaluations exceeding the intra-site level, it is particularly important that such data is collected in large numbers and that the dates are easily accessible. Also, new statistical analyses, such as sequential calibration based on Bayesian methods, do not require single dates, but rather demand a greater number. By their combination significantly more elaborate results can be achieved compared to the results from conventional evaluation (e. g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This approach continues to be applied in the international research community, which we welcome as a highly positive development. The radiocarbon database RADON has been committed to this principle for more than 12 years. In this database 14C data – primarily of the Neolithic of Central Europe and Southern Scandinavia – is collected and successively augmented.}
}
@misc{AUD 1997, 373,
  
}
@misc{AUD 1992, 300,
  
}
@misc{AUD 1997, 273,
  
}
@misc{AUD 1991, 239,
  
}
@misc{AUD 1992, 299,
  
}
@misc{AUD 1992 300,
  
}
@misc{AUD 1992 299,
  
}
@misc{AUD 1997 273,
  
}
@misc{AUD 1997 373,
  
}
@misc{CalPal,
  title = {CalPal Edition 2022.9},
  author = {Weninger, Bernie},
  year = {2022},
  month = {sep},
  doi = {1010.5281/zenodo.7422618},
  url = {https://zenodo.org/record/7422618},
  abstract = {CalPal is scientific freeware for 14C-based chronological research for Holocene and Palaeolithic Archaeology.},
  copyright = {Creative Commons Attribution 4.0 International, Open Access},
  howpublished = {Zenodo},
  month_numeric = {9}
}
@article{RADON,
  title = {RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age.},
  author = {Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian, Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter},
  date = {2012},
  journaltitle = {Journal of Neolithic Archaeology},
  volume = {14},
  pages = {1–4},
  url = {https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116},
  abstract = {In order to understand the dynamics of cultural phenomena, scientific dating in archaeology is an increasingly indispensable tool. Only by dating independently of typology is it possible to understand typological development itself (Müller 2004). Here radiometric dating methods, especially those based on carbon isotopy, still play the most important role. For evaluations exceeding the intra-site level, it is particularly important that such data is collected in large numbers and that the dates are easily accessible. Also, new statistical analyses, such as sequential calibration based on Bayesian methods, do not require single dates, but rather demand a greater number. By their combination significantly more elaborate results can be achieved compared to the results from conventional evaluation (e. g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This approach continues to be applied in the international research community, which we welcome as a highly positive development. The radiocarbon database RADON has been committed to this principle for more than 12 years. In this database 14C data – primarily of the Neolithic of Central Europe and Southern Scandinavia – is collected and successively augmented.}
}
@article{p3k14c,
  title = {P3k14c, a Synthetic Global Database of Archaeological Radiocarbon Dates},
  author = {Bird, Darcy and Miranda, Lux and Vander Linden, Marc and Robinson, Erick and Bocinsky, R. Kyle and Nicholson, Chris and Capriles, José M. and Finley, Judson Byrd and Gayo, Eugenia M. and Gil, Adolfo and d’Alpoim Guedes, Jade and Hoggarth, Julie A. and Kay, Andrea and Loftus, Emma and Lombardo, Umberto and Mackie, Madeline and Palmisano, Alessio and Solheim, Steinar and Kelly, Robert L. and Freeman, Jacob},
  year = {2022},
  month = {jan},
  journal = {Scientific Data},
  volume = {9},
  number = {1},
  pages = {27},
  publisher = {Nature Publishing Group},
  issn = {2052-4463},
  doi = {10.1038/s41597-022-01118-7},
  abstract = {Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according to a standardized sample selection criteria. This database increases the reusability of archaeological radiocarbon data and streamlines quality control assessments for various types of paleo-demographic research. As part of an assessment of data quality, we conduct two analyses of sampling bias in the global database at multiple scales. This database is ideal for paleo-demographic research focused on dates-as-data, bayesian modeling, or summed probability distribution methodologies.},
  copyright = {2022 The Author(s)},
  langid = {english},
  keywords = {Archaeology,Chemistry},
  month_numeric = {1}
}

[{"bibtex_key":"RADON","bibtex_type":"article","title":"{RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age.}","author":"{Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian, Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter}","date":"{2012}","journaltitle":"{Journal of Neolithic Archaeology}","volume":"{14}","pages":"{1–4}","url":"{https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116}","abstract":"{In order to understand the dynamics of cultural phenomena, scientific dating in archaeology is an increasingly indispensable tool. Only by dating independently of typology is it possible to understand typological development itself (Müller 2004). Here radiometric dating methods, especially those based on carbon isotopy, still play the most important role. For evaluations exceeding the intra-site level, it is particularly important that such data is collected in large numbers and that the dates are easily accessible. Also, new statistical analyses, such as sequential calibration based on Bayesian methods, do not require single dates, but rather demand a greater number. By their combination significantly more elaborate results can be achieved compared to the results from conventional evaluation (e. g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This approach continues to be applied in the international research community, which we welcome as a highly positive development. The radiocarbon database RADON has been committed to this principle for more than 12 years. In this database 14C data – primarily of the Neolithic of Central Europe and Southern Scandinavia – is collected and successively augmented.}"}]{"bibtex_key":"AUD 1997, 373","bibtex_type":"misc"}{"bibtex_key":"AUD 1992, 300","bibtex_type":"misc"}{"bibtex_key":"AUD 1997, 273","bibtex_type":"misc"}{"bibtex_key":"AUD 1991, 239","bibtex_type":"misc"}{"bibtex_key":"AUD 1992, 299","bibtex_type":"misc"}{"bibtex_key":"AUD 1992 300","bibtex_type":"misc"}{"bibtex_key":"AUD 1992 299","bibtex_type":"misc"}{"bibtex_key":"AUD 1997 273","bibtex_type":"misc"}{"bibtex_key":"AUD 1997 373","bibtex_type":"misc"}[{"bibtex_key":"CalPal","bibtex_type":"misc","title":"{CalPal Edition 2022.9}","author":"{Weninger, Bernie}","year":"{2022}","month":"{sep}","doi":"{1010.5281/zenodo.7422618}","url":"{https://zenodo.org/record/7422618}","abstract":"{CalPal is scientific freeware for 14C-based chronological research for Holocene and Palaeolithic Archaeology.}","copyright":"{Creative Commons Attribution 4.0 International, Open Access}","howpublished":"{Zenodo}","month_numeric":"{9}"}][{"bibtex_key":"RADON","bibtex_type":"article","title":"{RADON - Radiocarbon Dates Online 2012. Central European Database of 14C Dates for the Neolithic and the Early Bronze Age.}","author":"{Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian, Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter}","date":"{2012}","journaltitle":"{Journal of Neolithic Archaeology}","volume":"{14}","pages":"{1–4}","url":"{https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116}","abstract":"{In order to understand the dynamics of cultural phenomena, scientific dating in archaeology is an increasingly indispensable tool. Only by dating independently of typology is it possible to understand typological development itself (Müller 2004). Here radiometric dating methods, especially those based on carbon isotopy, still play the most important role. For evaluations exceeding the intra-site level, it is particularly important that such data is collected in large numbers and that the dates are easily accessible. Also, new statistical analyses, such as sequential calibration based on Bayesian methods, do not require single dates, but rather demand a greater number. By their combination significantly more elaborate results can be achieved compared to the results from conventional evaluation (e. g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This approach continues to be applied in the international research community, which we welcome as a highly positive development. The radiocarbon database RADON has been committed to this principle for more than 12 years. In this database 14C data – primarily of the Neolithic of Central Europe and Southern Scandinavia – is collected and successively augmented.}"}][{"bibtex_key":"p3k14c","bibtex_type":"article","title":"{P3k14c, a Synthetic Global Database of Archaeological Radiocarbon Dates}","author":"{Bird, Darcy and Miranda, Lux and Vander Linden, Marc and Robinson, Erick and Bocinsky, R. Kyle and Nicholson, Chris and Capriles, José M. and Finley, Judson Byrd and Gayo, Eugenia M. and Gil, Adolfo and d’Alpoim Guedes, Jade and Hoggarth, Julie A. and Kay, Andrea and Loftus, Emma and Lombardo, Umberto and Mackie, Madeline and Palmisano, Alessio and Solheim, Steinar and Kelly, Robert L. and Freeman, Jacob}","year":"{2022}","month":"{jan}","journal":"{Scientific Data}","volume":"{9}","number":"{1}","pages":"{27}","publisher":"{Nature Publishing Group}","issn":"{2052-4463}","doi":"{10.1038/s41597-022-01118-7}","abstract":"{Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according to a standardized sample selection criteria. This database increases the reusability of archaeological radiocarbon data and streamlines quality control assessments for various types of paleo-demographic research. As part of an assessment of data quality, we conduct two analyses of sampling bias in the global database at multiple scales. This database is ideal for paleo-demographic research focused on dates-as-data, bayesian modeling, or summed probability distribution methodologies.}","copyright":"{2022 The Author(s)}","langid":"{english}","keywords":"{Archaeology,Chemistry}","month_numeric":"{1}"}]

---
- :bibtex_key: RADON
  :bibtex_type: :article
  :title: "{RADON - Radiocarbon Dates Online 2012. Central European Database of 14C
    Dates for the Neolithic and the Early Bronze Age.}"
  :author: "{Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian,
    Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter}"
  :date: "{2012}"
  :journaltitle: "{Journal of Neolithic Archaeology}"
  :volume: "{14}"
  :pages: "{1–4}"
  :url: "{https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116}"
  :abstract: "{In order to understand the dynamics of cultural phenomena, scientific
    dating in archaeology is an increasingly indispensable tool. Only by dating independently
    of typology is it possible to understand typological development itself (Müller
    2004). Here radiometric dating methods, especially those based on carbon isotopy,
    still play the most important role. For evaluations exceeding the intra-site level,
    it is particularly important that such data is collected in large numbers and
    that the dates are easily accessible. Also, new statistical analyses, such as
    sequential calibration based on Bayesian methods, do not require single dates,
    but rather demand a greater number. By their combination significantly more elaborate
    results can be achieved compared to the results from conventional evaluation (e.
    g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This
    approach continues to be applied in the international research community, which
    we welcome as a highly positive development. The radiocarbon database RADON has
    been committed to this principle for more than 12 years. In this database 14C
    data – primarily of the Neolithic of Central Europe and Southern Scandinavia –
    is collected and successively augmented.}"
---
:bibtex_key: AUD 1997, 373
:bibtex_type: :misc
---
:bibtex_key: AUD 1992, 300
:bibtex_type: :misc
---
:bibtex_key: AUD 1997, 273
:bibtex_type: :misc
---
:bibtex_key: AUD 1991, 239
:bibtex_type: :misc
---
:bibtex_key: AUD 1992, 299
:bibtex_type: :misc
---
:bibtex_key: AUD 1992 300
:bibtex_type: :misc
---
:bibtex_key: AUD 1992 299
:bibtex_type: :misc
---
:bibtex_key: AUD 1997 273
:bibtex_type: :misc
---
:bibtex_key: AUD 1997 373
:bibtex_type: :misc
---
- :bibtex_key: CalPal
  :bibtex_type: :misc
  :title: "{CalPal Edition 2022.9}"
  :author: "{Weninger, Bernie}"
  :year: "{2022}"
  :month: "{sep}"
  :doi: "{1010.5281/zenodo.7422618}"
  :url: "{https://zenodo.org/record/7422618}"
  :abstract: "{CalPal is scientific freeware for 14C-based chronological research
    for Holocene and Palaeolithic Archaeology.}"
  :copyright: "{Creative Commons Attribution 4.0 International, Open Access}"
  :howpublished: "{Zenodo}"
  :month_numeric: "{9}"
---
- :bibtex_key: RADON
  :bibtex_type: :article
  :title: "{RADON - Radiocarbon Dates Online 2012. Central European Database of 14C
    Dates for the Neolithic and the Early Bronze Age.}"
  :author: "{Hinz, Martin and Furholt, Martin and Müller, Johannes and Raetzel-Fabian,
    Dirk and Rinne, Christophe and Sjögren, Karl-Göran and Wotzka, Hans-Peter}"
  :date: "{2012}"
  :journaltitle: "{Journal of Neolithic Archaeology}"
  :volume: "{14}"
  :pages: "{1–4}"
  :url: "{https://www.jna.uni-kiel.de/index.php/jna/article/view/65/116}"
  :abstract: "{In order to understand the dynamics of cultural phenomena, scientific
    dating in archaeology is an increasingly indispensable tool. Only by dating independently
    of typology is it possible to understand typological development itself (Müller
    2004). Here radiometric dating methods, especially those based on carbon isotopy,
    still play the most important role. For evaluations exceeding the intra-site level,
    it is particularly important that such data is collected in large numbers and
    that the dates are easily accessible. Also, new statistical analyses, such as
    sequential calibration based on Bayesian methods, do not require single dates,
    but rather demand a greater number. By their combination significantly more elaborate
    results can be achieved compared to the results from conventional evaluation (e.
    g. Whittle et al. 2011). A second premise of RADON is that of „Open Access“. This
    approach continues to be applied in the international research community, which
    we welcome as a highly positive development. The radiocarbon database RADON has
    been committed to this principle for more than 12 years. In this database 14C
    data – primarily of the Neolithic of Central Europe and Southern Scandinavia –
    is collected and successively augmented.}"
---
- :bibtex_key: p3k14c
  :bibtex_type: :article
  :title: "{P3k14c, a Synthetic Global Database of Archaeological Radiocarbon Dates}"
  :author: "{Bird, Darcy and Miranda, Lux and Vander Linden, Marc and Robinson, Erick
    and Bocinsky, R. Kyle and Nicholson, Chris and Capriles, José M. and Finley, Judson
    Byrd and Gayo, Eugenia M. and Gil, Adolfo and d’Alpoim Guedes, Jade and Hoggarth,
    Julie A. and Kay, Andrea and Loftus, Emma and Lombardo, Umberto and Mackie, Madeline
    and Palmisano, Alessio and Solheim, Steinar and Kelly, Robert L. and Freeman,
    Jacob}"
  :year: "{2022}"
  :month: "{jan}"
  :journal: "{Scientific Data}"
  :volume: "{9}"
  :number: "{1}"
  :pages: "{27}"
  :publisher: "{Nature Publishing Group}"
  :issn: "{2052-4463}"
  :doi: "{10.1038/s41597-022-01118-7}"
  :abstract: "{Archaeologists increasingly use large radiocarbon databases to model
    prehistoric human demography (also termed paleo-demography). Numerous independent
    projects, funded over the past decade, have assembled such databases from multiple
    regions of the world. These data provide unprecedented potential for comparative
    research on human population ecology and the evolution of social-ecological systems
    across the Earth. However, these databases have been developed using different
    sample selection criteria, which has resulted in interoperability issues for global-scale,
    comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental
    data. We present a synthetic, global-scale archaeological radiocarbon database
    composed of 180,070 radiocarbon dates that have been cleaned according to a standardized
    sample selection criteria. This database increases the reusability of archaeological
    radiocarbon data and streamlines quality control assessments for various types
    of paleo-demographic research. As part of an assessment of data quality, we conduct
    two analyses of sampling bias in the global database at multiple scales. This
    database is ideal for paleo-demographic research focused on dates-as-data, bayesian
    modeling, or summed probability distribution methodologies.}"
  :copyright: "{2022 The Author(s)}"
  :langid: "{english}"
  :keywords: "{Archaeology,Chemistry}"
  :month_numeric: "{1}"

Changelog

Imported from source database via c14bazAAR

XRONOS development team 2022-12-02 00:50:45 UTC

Location

Linked Data

Radiocarbon dates (16)

Typological dates (15)

Bibliographic references

Changelog

Imported from source database via c14bazAAR