A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments. / Blockley, Simon; Pyne-O’Donnell, S.D.F.; Lowe, John; Matthews, Ian; Stone, A.; Pollard, A.M.; Turney, C.S.M.; Molyneux, E.G.

In: Quaternary Science Reviews, Vol. 24, No. 16-17, 09.2005, p. 1952-1960.

Research output: Contribution to journalArticle

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A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments. / Blockley, Simon; Pyne-O’Donnell, S.D.F.; Lowe, John; Matthews, Ian; Stone, A.; Pollard, A.M.; Turney, C.S.M.; Molyneux, E.G.

In: Quaternary Science Reviews, Vol. 24, No. 16-17, 09.2005, p. 1952-1960.

Research output: Contribution to journalArticle

Harvard

Blockley, S, Pyne-O’Donnell, SDF, Lowe, J, Matthews, I, Stone, A, Pollard, AM, Turney, CSM & Molyneux, EG 2005, 'A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments', Quaternary Science Reviews, vol. 24, no. 16-17, pp. 1952-1960. https://doi.org/doi:10.1016/j.quascirev.2004.12.008

APA

Blockley, S., Pyne-O’Donnell, S. D. F., Lowe, J., Matthews, I., Stone, A., Pollard, A. M., Turney, C. S. M., & Molyneux, E. G. (2005). A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments. Quaternary Science Reviews, 24(16-17), 1952-1960. https://doi.org/doi:10.1016/j.quascirev.2004.12.008

Vancouver

Author

Blockley, Simon ; Pyne-O’Donnell, S.D.F. ; Lowe, John ; Matthews, Ian ; Stone, A. ; Pollard, A.M. ; Turney, C.S.M. ; Molyneux, E.G. / A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments. In: Quaternary Science Reviews. 2005 ; Vol. 24, No. 16-17. pp. 1952-1960.

BibTeX

@article{5c88335ee9fb427696cc424abd9f7414,
title = "A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments",
abstract = "Tephrochronology, a key tool in the correlation of Quaternary sequences, relies on the extraction of tephra shards from sediments for visual identification and high-precision geochemical comparison. A prerequisite for the reliable correlation of tephra layers is that the geochemical composition of glass shards remains unaltered by natural processes (e.g. chemical exchange in the sedimentary environment) and/or by laboratory analytical procedures. However, natural glasses, particularly when in the form of small shards with a high surface to volume ratio, are prone to chemical alteration in both acidic and basic environments. Current techniques for the extraction of distal tephra from sediments involve the 'cleaning' of samples in precisely such environments and at elevated temperatures. The acid phase of the 'cleaning' process risks alteration of the geochemical signature of the shards, while the basic phase leads to considerable sample loss through dissolution of the silica network. Here, we illustrate the degree of alteration and loss to which distal tephras may be prone, and introduce a less destructive procedure for their extraction. This method is based on stepped heavy liquid flotation and which results in samples of sufficient quality for analysis while preserving their geochemical integrity. In trials, this method out-performed chemical extraction procedures in terms of the number of shards recovered and has resulted in the detection of new tephra layers with low shard concentrations. The implications of this study are highly significant because (i) the current database of distal tephra records and their corresponding geochemical signatures may require refinement and (ii) the record of distal tephras may be incomplete due to sample loss induced by corrosive laboratory procedures. It is therefore vital that less corrosive laboratory procedures are developed to make the detection and classification of distal glass tephra more secure. (c) 2005 Elsevier Ltd. All rights reserved.",
keywords = "Tephra, Extraction, Chemical alteration, Density floatation",
author = "Simon Blockley and S.D.F. Pyne-O{\textquoteright}Donnell and John Lowe and Ian Matthews and A. Stone and A.M. Pollard and C.S.M. Turney and E.G. Molyneux",
year = "2005",
month = sep,
doi = "doi:10.1016/j.quascirev.2004.12.008",
language = "English",
volume = "24",
pages = "1952--1960",
journal = "Quaternary Science Reviews",
issn = "0277-3791",
publisher = "Elsevier Limited",
number = "16-17",

}

RIS

TY - JOUR

T1 - A new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments

AU - Blockley, Simon

AU - Pyne-O’Donnell, S.D.F.

AU - Lowe, John

AU - Matthews, Ian

AU - Stone, A.

AU - Pollard, A.M.

AU - Turney, C.S.M.

AU - Molyneux, E.G.

PY - 2005/9

Y1 - 2005/9

N2 - Tephrochronology, a key tool in the correlation of Quaternary sequences, relies on the extraction of tephra shards from sediments for visual identification and high-precision geochemical comparison. A prerequisite for the reliable correlation of tephra layers is that the geochemical composition of glass shards remains unaltered by natural processes (e.g. chemical exchange in the sedimentary environment) and/or by laboratory analytical procedures. However, natural glasses, particularly when in the form of small shards with a high surface to volume ratio, are prone to chemical alteration in both acidic and basic environments. Current techniques for the extraction of distal tephra from sediments involve the 'cleaning' of samples in precisely such environments and at elevated temperatures. The acid phase of the 'cleaning' process risks alteration of the geochemical signature of the shards, while the basic phase leads to considerable sample loss through dissolution of the silica network. Here, we illustrate the degree of alteration and loss to which distal tephras may be prone, and introduce a less destructive procedure for their extraction. This method is based on stepped heavy liquid flotation and which results in samples of sufficient quality for analysis while preserving their geochemical integrity. In trials, this method out-performed chemical extraction procedures in terms of the number of shards recovered and has resulted in the detection of new tephra layers with low shard concentrations. The implications of this study are highly significant because (i) the current database of distal tephra records and their corresponding geochemical signatures may require refinement and (ii) the record of distal tephras may be incomplete due to sample loss induced by corrosive laboratory procedures. It is therefore vital that less corrosive laboratory procedures are developed to make the detection and classification of distal glass tephra more secure. (c) 2005 Elsevier Ltd. All rights reserved.

AB - Tephrochronology, a key tool in the correlation of Quaternary sequences, relies on the extraction of tephra shards from sediments for visual identification and high-precision geochemical comparison. A prerequisite for the reliable correlation of tephra layers is that the geochemical composition of glass shards remains unaltered by natural processes (e.g. chemical exchange in the sedimentary environment) and/or by laboratory analytical procedures. However, natural glasses, particularly when in the form of small shards with a high surface to volume ratio, are prone to chemical alteration in both acidic and basic environments. Current techniques for the extraction of distal tephra from sediments involve the 'cleaning' of samples in precisely such environments and at elevated temperatures. The acid phase of the 'cleaning' process risks alteration of the geochemical signature of the shards, while the basic phase leads to considerable sample loss through dissolution of the silica network. Here, we illustrate the degree of alteration and loss to which distal tephras may be prone, and introduce a less destructive procedure for their extraction. This method is based on stepped heavy liquid flotation and which results in samples of sufficient quality for analysis while preserving their geochemical integrity. In trials, this method out-performed chemical extraction procedures in terms of the number of shards recovered and has resulted in the detection of new tephra layers with low shard concentrations. The implications of this study are highly significant because (i) the current database of distal tephra records and their corresponding geochemical signatures may require refinement and (ii) the record of distal tephras may be incomplete due to sample loss induced by corrosive laboratory procedures. It is therefore vital that less corrosive laboratory procedures are developed to make the detection and classification of distal glass tephra more secure. (c) 2005 Elsevier Ltd. All rights reserved.

KW - Tephra

KW - Extraction

KW - Chemical alteration

KW - Density floatation

U2 - doi:10.1016/j.quascirev.2004.12.008

DO - doi:10.1016/j.quascirev.2004.12.008

M3 - Article

VL - 24

SP - 1952

EP - 1960

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

SN - 0277-3791

IS - 16-17

ER -