Hi everybody,
Does anybody know if some oxygen isotope
studies on abiogenic (specially precious) opal exist ?
I am aware of many studies on diagenesis of biogenic opal 
(cherts,...), but very few on non-biogenic opal (most of them
from oceanic environments-silica chimneys, etc-,
but none from continental environments).
Thanks in advance for some informations.
Cheers
Albert Gilg
-----------------------------
H. Albert Gilg
Lehrstuhl fuer Angewandte 
Mineralogie und Geochemie
Technische Universitaet Muenchen
Lichtenbergstr. 4
D-85747 GARCHING - Germany
Tel.:++49/89/3209-3196
Fax.:++49/89/3209-3205
e-mail: [log in to unmask]