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(Article of periodic en Anglais - 2014)

Document title

Differential roles of plagioclase and biotite in the early stage weathering of granite : a solid-sided approach combining laboratory experiment and surface analysis

Authors(s) and Affiliation(s)

TAKAYA Y. (1) ; HATTA T. (2) ; MATSUKURA Y. (3) ;
(1) Center for Spatial Information Science, Univ., Tokyo, JAPON
(2) Japan International Research Center for Agricultural Sciences, Ibaraki, JAPON
(3) Fac. of Life and Environmental Sciences, Univ., Tsukuba, JAPON

Abstract

An experiment was carried out on uncrushed samples of granite and 4 minerals (single crystals of annite, albite, microcline, and quartz) in a closed system at room temperature for 56 days. The chemistry of the resulting surface was determined through XPS. The specific features of granite were confirmed by comparing them with the individual minerals. It was found that biotite played the central role in early stage weathering of the granite samples from a solid analytical viewpoint. Furthermore, plagioclase played the background role in near-neutral to acidic conditions. The increase of pH level due to plagioclase dissolution promoted Fe-oxide precipitation from biotite. Moreover, the precipitation of products including Al started slower, mainly because of its lower dissolution performance. This phenomenon led to an increase in the reactivity of biotite. Under more acidic conditions, the dissolution of biotite was dominant and constituent minerals had no influence on each other. The inter-mineral effect operated via pH fluctuation, as the weathering characteristics of the individual minerals depended on pH levels

Source

Article of periodic

published at : Zeitschrift für Geomorphologie / ISSN 0372-8854 / CODEN ZGMPAG

Editor : Gebruder Borntraeger, Stuttgart - ALLEMAGNE (1925)

Millesime : 2014, vol. 58, no2 [pp. 233-249]

Bibliographic references : 26 ref.

Collation : 9 fig., 4 tabl.

Language

Anglais

INIST-CNRS, Cote INIST : 8829

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1127/0372-8854/2014/0123

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2014
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