Thanks, Ethan.  Also thanks for the favorable review of our Geology
article.  Unfortunately, it was rejected due to a 2nd reviewers comment.
Basically he stated that since Baross and Deming have found bacteria in
very hot vent plumes, that survival of bacteria at temperatures greater
than 120 degrees C is not a problem.  Therefore we have no evidence of
microbial transport at Parachute, they are all survivors.  Gee, if it were
just that simple then we could have saved a lot of money.  By the way, how
is your student doing on the Piceance gas samples?  I was wondering if you
were preparing a paper for it and if there is any kind of info that you
might need that we could provide?  For instance, during my write up of the
Taylorsville study I discovered that it is likely that in natural gas rich
deposits the free energy for methanogenesis goes positive.  Maybe this
would explain the lack of methanogens deep at Piceance basin??  We might
have enough information to test that hypothesis.  Cheers, T.C.O.

>TC:
>
>Try: Hassan, A.A., 1982, Methodologies for extraction of dissolved
>inorganic carbon for stable carbon isotope studies: evaluation and
>alternatives. U.S.G.S. Water Resources Investigations, 82-6.  Also, there
>has been some Isogeochem discussion on this.  Researchers seem to favor
>acid-stripping from water over precipitation of carbonate precipitate
>(including me), but the latter is commonly used.  See Hassan's study.
>
>Ethan
>
>**********
>
>>Dear Isogeochemers,
>>I was wondering if I could obtain a survey of the relative merits of sampling
>>ground water for the del-13C of inorganic carbon with either of these two
>>
>>methods:
>>1.  Collecting water poisoned by HgCl2 and then acidified by phosphoric acid
>>in
>>the lab.
>>2.  Collecting water with BaCl2 or SrCl2 allowing BaCO3 or SrCO3 to form.
>>Filtering the precipitate and then acidifying with phosphoric acid in the lab.
>>
>>Are there any publications that compare the accuracies of each approach?
>>Any advice would be greatly appreciated.  Thanks, T.C. Onstott
>
>Department of Geology & Geophysics                  (409) 845-0637
>Texas A&M University                            fax (409) 845-6162
>College Station, TX 77843-3115