Sign up & Download
Sign in

Hydrothermal alteration of plagioclase in granitic rocks from Proterozoic basement of SE Sweden

by S Morad, M A K El-Ghali, M A Caja, M Sirat, Khalid Al-Ramadan, H Mansurbeg
Geological Journal ()

Abstract

Petrographic examinations and electron microprobe analyses of Proterozoic granitic rocks, SE Sweden aimed to characterize and unravel the mechanisms and conditions of plagioclase alterations. These alterations include saussuritization, albitization and replacement of plagioclase by K-feldspar. The hydrothermal alterations, which are inferred to have occurred at ca. 250-400°C, resulted in concomitant formation of Al-rich titanite, epidote, calcite, pumpellyite, prehnite and iron oxides. Replacement of plagioclase by K-feldspar occurs in red-stained zones, which have developed close to thin fractures owing to the precipitation of tiny Fe-oxide pigment particles within the altered plagioclase, whereas saussuritized plagioclase has less systematic spatial relationships to these fractures. Albitization of plagioclase occurred in rocks that are poor in biotite compared to rocks that suffered extensive saussuritization. The chemical and textural characterization of various types of plagioclase alterations allows elucidation of the granitic hydrothermal systems. Features of feldspar alteration in the granitic rocks are similar to those encountered in feldspathic sandstones and should hence be considered in studies on diagenetic changes of siliciclastic successions during basin evolution. Copyright © 2009 John Wiley & Sons, Ltd.

Cite this document (BETA)

Readership Statistics

7 Readers on Mendeley
by Discipline
 
by Academic Status
 
43% Ph.D. Student
 
14% Student (Bachelor)
 
14% Lecturer
by Country
 
14% Germany
 
14% Spain
 
14% France

Tags

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Already have an account? Sign in