Dear Collegues,
working in a shear zone setting with a large amount of hydration recorded
in the shear zone assemblages (Dent Blanche nappe, western Alps), I was
hoping to apply microthermometry on secondary fluid-inclusions in quartz.
This quest unfortunately was stopped by the small inclusion size (3-5µm)
which is below the resolution of our analytical setup (40mag on the
microscope). This brought up my question: What originally determines the
size of secondary fluid inclusions? Is it the volume of fluid present in
the rock while fracturing of the minerals take place? This seems to be
unlikely for the above mentioned "wet" shear zone setting. Is it the stress
regime active and leading to fracturing (constrictional vs extensional)? I
invite your comments and ideas, if there might be recent papers dealing
with this question, please let me know.
Cheers
Dirk
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Dirk Hellwig
Department of Geosciences
Philipps-University Marburg
Hans-Meerwein-Strasse
35032 Marburg/Germany
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phone: +49-6421-2823055
fax: +49-6421-2828919
http://staff-www.uni-marburg.de/~hellwig/
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