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(Article of periodic en Anglais - 2013)

Document title

Where fast weathering creates thin regolith and slow weathering creates thick regolith

Authors(s) and Affiliation(s)

BAZILEVSKAYA E. (1) ; LEBEDEVA M. (1) ; PAVICH M. (2) ; ROTHER G. (3) ; PARKINSON D.Y. (4) ; COLE D. (5) ; BRANTLEY S.L. (1) ;
(1) Earth and Environmental Systems Inst., State Univ., Penn Hills, ETATS-UNIS
(2) US Geological Survey, Eastern Geology and Paleoclimate Science Center, Reston, ETATS-UNIS
(3) Geochemistry and Interfacial Sciences Group, Chemical Sciences Div., National Lab., Oak Ridge, ETATS-UNIS
(4) Advanced Light Source, Lawrence Berkeley National Lab., Berkeley, ETATS-UNIS
(5) School of Earth Sciences, Ohio State Univ., Columbus, ETATS-UNIS

Abstract

Here, the AA. investigate what controls the depth of regolith formed on ridges of 2 rock compositions with similar initial porosities in Virginia (USA). A priori, they predicted that the regolith on diabase would be thicker than on granite because the dominant mineral (feldspar) in the diabase weathers faster than its granitic counterpart. However, weathering advanced 20x deeper into the granite than the diabase. This is attributed mainly to connected micron-sized pores, microfractures formed around oxidizing biotite at 20 m depth, and the lower iron (Fe) content in the felsic rock. Such porosity allows pervasive advection and deep oxidation in the granite. These observations may explain why regolith worldwide is thicker on felsic compared to mafic rock under similar conditions. To understand regolith formation will require better understanding of such deep oxidation reactions and how they impact fluid flow during weathering

Source

Article of periodic

published at : Earth surface processes and landforms / ISSN 0197-9337 / CODEN ESPLDB

Editor : Wiley, Chichester - ROYAUME-UNI (1981)

Millesime : 2013, vol. 38, no8 [pp. 847-858]

Bibliographic references : 2 p.

Collation : 5 fig., 3 tabl., 2 annexes

Language

Anglais

INIST-CNRS, Cote INIST : 17355

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1002/esp.3369

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