(Article of periodic en Anglais - 2013)

Document title

Varnish microlaminations : new insights from focused ion beam preparation

Authors(s) and Affiliation(s)

KRINSLEY D. (1) ; DITTO J. (2) ; LANGWORTHY K. (2) ; DORN R.I. (3) ; THOMPSON T. (3) ;
(1) Dep. of Geological Sciences, Univ. Oregon, Eugene, ETATS-UNIS
(2) Dep. of Chemistry, Center for Advanced Materials Characterization in Oregon, Univ. Oregon, Eugene, ETATS-UNIS
(3) School of Geographical Sciences and Urban Planning, Arizona State Univ., Tempe, ETATS-UNIS


The cross-sectional texture of rock varnish varies considerably with the scale of analysis and technique used to image a sample. One key to nanoscale analysis involves focused ion beam (FIB) techniques, but FIB preparation remains challenging for samples like rock coatings with heterogeneous density and abundant porosity. A new technique involving multiangle ion thinning and in situ plan-view lift-out facilitated a scanning transmission electron microscopy study of rock varnish from Death Valley. The results reveal variability in lateral continuity of nanometer microlaminae that can be interrupted by post-depositional diagenesis involving leaching of Mn and Fe, and this variability could explain why some of the visual varnish microlaminations (VML) used in paleoclimatic research can sometimes appear discontinuous. Because these breaks result from post-depositional processes, they do not undermine the paleoclimatic interpretations of VML


Article of periodic

published at : Physical geography / ISSN 0272-3646

Editor : Taylor & Francis, Abingdon - ROYAUME-UNI (1980)

Millesime : 2013, vol. 34, no3 [pp. 159-173]

Bibliographic references : 2 p.

Collation : 11 fig., 1 tabl.



INIST-CNRS, Cote INIST : 20106

Digital Object Identifier

Go to electronic document thanks to its DOI : doi:10.1080/02723646.2013.830926

Tous droits réservés © Prodig - Bibliographie Géographique Internationale (BGI), 2013
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