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Titolo:
Trace elements of Paleocene Tachira coals, southwestern Venezuela: a geochemical study
Autore:
Martinez, M; Escobar, M; Esteves, I; Lopez, C; Galarraga, F; Gonzalez, R;
Indirizzi:
Cent Univ Venezuela, Fac Ciencias, Inst Ciencias Tierra, Caracas 1010A, Venezuela Cent Univ Venezuela Caracas Venezuela 1010A ra, Caracas 1010A, Venezuela
Titolo Testata:
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
fascicolo: 4, volume: 14, anno: 2001,
pagine: 387 - 399
SICI:
0895-9811(200109)14:4<387:TEOPTC>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
SOUTH-WALES; BASIN; ASSOCIATION; SULFUR;
Keywords:
coal; trace elements; geochemistry; factor analysis; Venezuela;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Martinez, M Cent Univ Venezuela, Fac Ciencias, Inst Ciencias Tierra, Apartado Postal 3895, Caracas 1010A, Venezuela Cent Univ Venezuela Apartado Postal 3895 Caracas Venezuela 1010A
Citazione:
M. Martinez et al., "Trace elements of Paleocene Tachira coals, southwestern Venezuela: a geochemical study", J S AM EART, 14(4), 2001, pp. 387-399

Abstract

The concentration and distribution of 35 elements in 78 coal samples from the Tachira State coal fields belonging to Los Cuervos Formation (Paleocene) of western Venezuela were obtained using atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission (ICP-AES). The aim of this work was to determine, through a multivariate statistical approach (factor analysis), if there is a correlation between the trace element content in coal beds and the provenance rocks at the time of peat deposition. Comparison with world averages and geometric means for trace element concentrations in coal-bed samples shows that B, Ba, La, V, Mn, Zn, and Ph are depleted. However, Tachira coal samples show a perceptible enrichment in Bi, Sb, As, Cd, and Mo, and they are highly enriched in Ag and Co. Nicholl's plot suggests that only B and Co show a distinctive organic affinity. Enriched elements (Ni, Ag, Cd, Mo, Co) are both statistically and genetically related, and we attribute their origin to a volcaniclastic Jurassic unit. Other statistical factors (Th-V-P and Ca-Mg-Mn) reveal a different provenance, indicating a felsic plutonic source and a sedimentary limestone, respectively. A fourth factor (K-Mo-Th-S) is composed mainly of clay minerals and authigenic sulfides. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 09:46:23