Greetings to all of you from Belfast, and many thanks to Andrea for
starting up this discussion group. My name is Jim Hendry and I'm a recent
addition to the Geology staff at QUB, after a PhD (carbonate sedimentology
/ diagenesis / stable isotopes) at Liverpool (Jim Marshall's lab) and
several years of post-doc contracts in Barcelona and Aberdeen.

My principal interests lie within applications of stable isotopes and
elemental geochemistry to problems of palaeoenvironment, diagenesis and
reservoir geology. As such I form part of a "Geofluids" research group
which has recently been set up at QUB, and embraces a range of expertise
from basin analysis, through kerogen maturation studies, reservoir geology,
ore mineralisation, and aqueous geochemistry.

In terms of isotope work, we enjoy close collaboration with the
laboratories of SURRC (Scottish Universities Research & Reactor Centre) in
East Kilbride. However, in-house facilities are also being developed by Bob
Kalin, one of our colleagues in the QUB Civil Engineering Dept. I'm no
expert on lab systems, so I'll leave Bob to post a message about the
hardware.

I look forward to the discussions on this list; I'm more of a "user" than a
"theoretician", but this will be a very useful way to keep abreast of the
developments in stable isotope geology.

Just to prove my ignorance, I'll post a question which has been bugging me
recently. I've been looking at ankerite cementation in some deeply buried
North Sea Basin sandstone reservoirs. The ankerites probably precipitated
at intermediate burial (? 2 km) but a variety of evidence (some admittedly
circumstantial) leads me to believe that their d18O ratios have been re-set
to present-day reservoir conditions (ie approximate eqm with current
formation fluids at B.H.T. of 170 - 190 deg.C). Elemental zoning patterns
in the cements argue against a wholesale recrystallisation, so.. can oxygen
isotope exchange occur between carbonates and fluids without bulk
recrystallisation at temperatures of c. 180 deg.C, or is some kind of
"thin-film" recrystallisation which preserves elemental zonation more
likely? Accepted lore is that solid-state oxygen isotope exchange does not
occur in the diagenetic environment - but what about at higher
temperatures? Any ideas are welcome!

Cheers

Jim

Dr Jim Hendry
Department of Geology
School of Geosciences
The Queen's University of Belfast
Belfast BT7 1NN
Northern Ireland
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Tel: 01232 245133 ext 3449
Fax: 01232 321280
E-mail: [log in to unmask]