Hi all,

first I wonder why Ilya Bindeman is interested only in work 'after 1993'? Yes,
sometimes the most recent work is the best, but in the scramble for funding and
attention, important points of view are sometimes overlooked, even if well known
in the past. Like Mike Palin, I will point to a "under-cited paper" that, apart
from its data, also might illuminate the relationship between theory and
experiment. Try "New evidence on magnetite oxygen isotope geothermometers at 175
and 112 deg C in Wairakei steam pipelines (New Zealand)" by Blattner,
Braithwaite and Glover, Isotope Geoscience 1 (1983) 195-204 (Ten years too
old!?). Main point: the quartz-magnetite function may be far from a straight
line. I do not think the pure theorists have tackled this one. Better to stick
to a "proven" formula?

Experiment decides: but which experiment? The "empirical" approach using natural
occurrences is one of the most promising, even if it seems to lack the glamour
of theory. See also (wrt quartz-calcite) Sharp and Kirshner GCA 58 4491-4501
(1994), and Blattner AJS 275 785-800 (1975) - that was before the age of chaos,
of course.

We can only perceive natural isotopes through the gate of analysis. If there is
systematic analytic bias between, say, silicates and water, no theory can help.
So mineral pairs are better in this way. That still leaves the problem of
closure temperatures.


Cheers!

Peter Blattner
c/GNS
PO Box 30368
Lower Hutt/ New Zealand