Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure

An objective procedure involving fourteen statistical tests (a total of thirty-four variants) for detection and rejection of outliers in a univariate sample was applied to five geochemical Reference Material (RM) databases of intrusive rocks from the Geological Survey of Japan (GSJ). All available c...

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Autores principales: Guevara, Mirna, Verma, Surendra P., Velasco Tapia, Fernando
Formato: Artículo
Lenguaje:inglés
Publicado: Universidad Nacional Autónoma de México. Instituto de Geología 2001
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Acceso en línea:http://eprints.uanl.mx/11854/1/Dialnet-EvaluationOfGSJIntrusiveRocksJG1JG2JG3JG1aAndJGb1B-281053.pdf
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author Guevara, Mirna
Verma, Surendra P.
Velasco Tapia, Fernando
author_facet Guevara, Mirna
Verma, Surendra P.
Velasco Tapia, Fernando
author_sort Guevara, Mirna
collection Repositorio Institucional
description An objective procedure involving fourteen statistical tests (a total of thirty-four variants) for detection and rejection of outliers in a univariate sample was applied to five geochemical Reference Material (RM) databases of intrusive rocks from the Geological Survey of Japan (GSJ). All available concentration data for JG1, JG1a, and JG3 granodiorites, JG2 granite, and JGb1 gabbro were first grouped in eight general analytical methods. These groups were tested for systematic differences using analysis of variance (ANOVA). After this process, the databases were evaluated by means of statistical tests for detection of possible outliers at a strict confidence level of 99%, minimizing the danger of rejecting a valid observation as an outlier. New concentration mean values and other statistical parameters were computed from final normal distributions. Although 23% of mean concentration values were practically identical to those reported in earlier literature, 67% differ by about 1% to 20%. The present statistical scheme provides a better perspective to evaluate existing geochemical databases than probably erroneous two-standard deviation method involving prior subjective judgments used by the U.S. and Japanese scientists. The present mean values with generally lower %RSD may contribute to a better estimation of precision, accuracy, and sensitivity of routine analysis for intrusive rock samples.
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spelling eprints-118542017-01-23T21:27:38Z http://eprints.uanl.mx/11854/ Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure Guevara, Mirna Verma, Surendra P. Velasco Tapia, Fernando QE Geología An objective procedure involving fourteen statistical tests (a total of thirty-four variants) for detection and rejection of outliers in a univariate sample was applied to five geochemical Reference Material (RM) databases of intrusive rocks from the Geological Survey of Japan (GSJ). All available concentration data for JG1, JG1a, and JG3 granodiorites, JG2 granite, and JGb1 gabbro were first grouped in eight general analytical methods. These groups were tested for systematic differences using analysis of variance (ANOVA). After this process, the databases were evaluated by means of statistical tests for detection of possible outliers at a strict confidence level of 99%, minimizing the danger of rejecting a valid observation as an outlier. New concentration mean values and other statistical parameters were computed from final normal distributions. Although 23% of mean concentration values were practically identical to those reported in earlier literature, 67% differ by about 1% to 20%. The present statistical scheme provides a better perspective to evaluate existing geochemical databases than probably erroneous two-standard deviation method involving prior subjective judgments used by the U.S. and Japanese scientists. The present mean values with generally lower %RSD may contribute to a better estimation of precision, accuracy, and sensitivity of routine analysis for intrusive rock samples. Universidad Nacional Autónoma de México. Instituto de Geología 2001 Article PeerReviewed text en cc_by_nc_nd http://eprints.uanl.mx/11854/1/Dialnet-EvaluationOfGSJIntrusiveRocksJG1JG2JG3JG1aAndJGb1B-281053.pdf http://eprints.uanl.mx/11854/1.haspreviewThumbnailVersion/Dialnet-EvaluationOfGSJIntrusiveRocksJG1JG2JG3JG1aAndJGb1B-281053.pdf Guevara, Mirna y Verma, Surendra P. y Velasco Tapia, Fernando (2001) Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure. Revista mexicana de ciencias geológicas, 18 (1). pp. 74-88. ISSN 0185-0962
spellingShingle QE Geología
Guevara, Mirna
Verma, Surendra P.
Velasco Tapia, Fernando
Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
thumbnail https://rediab.uanl.mx/themes/sandal5/images/online.png
title Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
title_full Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
title_fullStr Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
title_full_unstemmed Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
title_short Evaluation of GSJ instrusive rocks JG1, JG2, JG1a, and JGb1 by an objective outlier rejection statistical procedure
title_sort evaluation of gsj instrusive rocks jg1 jg2 jg1a and jgb1 by an objective outlier rejection statistical procedure
topic QE Geología
url http://eprints.uanl.mx/11854/1/Dialnet-EvaluationOfGSJIntrusiveRocksJG1JG2JG3JG1aAndJGb1B-281053.pdf
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