Identifying outliers and assessing the accuracy of amino acid racemization measurements for geochronology

II. Data screening

Matthew A. Kosnik, Darrell S Kaufman

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

Amino acid racemization (AAR) is a cost-effective method for dating the large numbers of specimens required for time-averaging studies. Because the aim of time-averaging studies is to determine the structure of the age distribution, any data screening must be done cautiously and systematically. Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed. Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency). This study is based on AAR analyses of 481 late Holocene shells of four molluscan taxa (Ethalia, Natica, Tellina, and Turbo) collected from shallow sediment cores from the central Great Barrier Reef. Different outliers are flagged by the different screening criteria, and 6% of specimens were found to be unsuitable for time-averaging analyses based on screening the raw AAR data. We recommend a hybrid approach for identifying outliers and specimens for numerical dating.

Original languageEnglish (US)
Pages (from-to)328-341
Number of pages14
JournalQuaternary Geochronology
Volume3
Issue number4
DOIs
StatePublished - Nov 2008

Fingerprint

racemization
outlier
geochronology
amino acid
aspartic acid
acid
barrier reef
age structure
sediment core
Holocene
shell
screening
cost
dating
method

Keywords

  • Amino acid geochronology
  • Amino acid racemization
  • Carbonate sediments
  • Great Barrier Reef
  • Holocene
  • Mollusca
  • Time-averaging

ASJC Scopus subject areas

  • Geology
  • Earth and Planetary Sciences (miscellaneous)
  • Stratigraphy

Cite this

Identifying outliers and assessing the accuracy of amino acid racemization measurements for geochronology : II. Data screening. / Kosnik, Matthew A.; Kaufman, Darrell S.

In: Quaternary Geochronology, Vol. 3, No. 4, 11.2008, p. 328-341.

Research output: Contribution to journalArticle

@article{d98f169289e14a93891599e4a56d0a41,
title = "Identifying outliers and assessing the accuracy of amino acid racemization measurements for geochronology: II. Data screening",
abstract = "Amino acid racemization (AAR) is a cost-effective method for dating the large numbers of specimens required for time-averaging studies. Because the aim of time-averaging studies is to determine the structure of the age distribution, any data screening must be done cautiously and systematically. Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed. Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency). This study is based on AAR analyses of 481 late Holocene shells of four molluscan taxa (Ethalia, Natica, Tellina, and Turbo) collected from shallow sediment cores from the central Great Barrier Reef. Different outliers are flagged by the different screening criteria, and 6{\%} of specimens were found to be unsuitable for time-averaging analyses based on screening the raw AAR data. We recommend a hybrid approach for identifying outliers and specimens for numerical dating.",
keywords = "Amino acid geochronology, Amino acid racemization, Carbonate sediments, Great Barrier Reef, Holocene, Mollusca, Time-averaging",
author = "Kosnik, {Matthew A.} and Kaufman, {Darrell S}",
year = "2008",
month = "11",
doi = "10.1016/j.quageo.2008.04.001",
language = "English (US)",
volume = "3",
pages = "328--341",
journal = "Quaternary Geochronology",
issn = "1871-1014",
publisher = "Elsevier",
number = "4",

}

TY - JOUR

T1 - Identifying outliers and assessing the accuracy of amino acid racemization measurements for geochronology

T2 - II. Data screening

AU - Kosnik, Matthew A.

AU - Kaufman, Darrell S

PY - 2008/11

Y1 - 2008/11

N2 - Amino acid racemization (AAR) is a cost-effective method for dating the large numbers of specimens required for time-averaging studies. Because the aim of time-averaging studies is to determine the structure of the age distribution, any data screening must be done cautiously and systematically. Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed. Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency). This study is based on AAR analyses of 481 late Holocene shells of four molluscan taxa (Ethalia, Natica, Tellina, and Turbo) collected from shallow sediment cores from the central Great Barrier Reef. Different outliers are flagged by the different screening criteria, and 6% of specimens were found to be unsuitable for time-averaging analyses based on screening the raw AAR data. We recommend a hybrid approach for identifying outliers and specimens for numerical dating.

AB - Amino acid racemization (AAR) is a cost-effective method for dating the large numbers of specimens required for time-averaging studies. Because the aim of time-averaging studies is to determine the structure of the age distribution, any data screening must be done cautiously and systematically. Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed. Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency). This study is based on AAR analyses of 481 late Holocene shells of four molluscan taxa (Ethalia, Natica, Tellina, and Turbo) collected from shallow sediment cores from the central Great Barrier Reef. Different outliers are flagged by the different screening criteria, and 6% of specimens were found to be unsuitable for time-averaging analyses based on screening the raw AAR data. We recommend a hybrid approach for identifying outliers and specimens for numerical dating.

KW - Amino acid geochronology

KW - Amino acid racemization

KW - Carbonate sediments

KW - Great Barrier Reef

KW - Holocene

KW - Mollusca

KW - Time-averaging

UR - http://www.scopus.com/inward/record.url?scp=44649186129&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=44649186129&partnerID=8YFLogxK

U2 - 10.1016/j.quageo.2008.04.001

DO - 10.1016/j.quageo.2008.04.001

M3 - Article

VL - 3

SP - 328

EP - 341

JO - Quaternary Geochronology

JF - Quaternary Geochronology

SN - 1871-1014

IS - 4

ER -