Geochemist'S Workbench: Fill & Download for Free

If you really mean the methodology, yes it has sort of changed. But one could argue that the method outlined in Garrels and Christ is still valid as an approach. But you have to understand how it was developed. The basic equations are still valid. Langmuir’s book (1997 Aqueous Environmental Geochemistry) still uses that approach (He was a student of Garrels’ at Harvard, and I believe his doctoral advisor, but not positive). Doug Brookins book (Eh-pH diagrams for Geochemists) also used the same approach, but it had a lot of errors in the free energies for the reaction constants it derived as it proceeded. so there are numerous errors look at the molybdenum figure for example; it is seriously wrong.Also the database in Garrels and Christ is probably very poor, and lacking in numerous species, and many free energy values could be suspect. So the conclusions drawn from those older plots, may no longer be valid. There has been a lot of newer data both related to ope deposit geochemistry and thermodynamic data since the late 1950’s and early 1960’s when those figures were originally prepared by various graduate students (even Harrison Schmitt the astronaut contributed).I still cover the approach in my geochemical modeling short courses, but I recently had an epiphany and realize that the computer generated methods particularly the method used by PhreePlot and in the HYDRA/MEDUSA package provide a better approach based upon a predominance calculation, which would be like looking as the top of a speciation plot. A recent paper by Huang ( The Eh-pH Diagram and its advances (Metals 2016, 6, 23; doi:10.3390/met6010023) provides a discussion of this newer method. But basically using a combination of speciation plots and Eh-pH diagrams allows one to look at all three dimensions of a system and relationships can be identified. PhreePlot also does Concentration contour diagrams and overlays. Go to this page on my website Mahoney Geochemical Consulting Services and scroll down near bottom for more information on this approach. This combination approach allows a better explanation of the underlying processes related to mineral formation.I do not believe that the approach used in Geochemists Workbench is the same as used by the other programs (H/M or PP). That tends to resemble the older Pourbaix and Garrels and Christ approach but it uses activities.If you are specifically interested in ore deposit formation I suspect a lot has changed, I took my Ore Deposit Geochemistry Class over 35 years ago so I cannot help you on current theories without more specifics. I do recall that even then things were in flux about what complexes formed and did what to form these deposits. Maybe look into Helgeson’s book ( another Garrels student) on ore deposits, but it is likely also be dated, and probably superseded by much newer experimental data.

Petroleum Geochemistry probably pays better, but might be less secure, I have several colleagues in that field (or petroleum engineering) and they were let go from a rather large company, there were several layoffs over a couple of years. Inorganic Geochemists can also work in the petroleum field, I consulted with them for several years before their ax fell on work related to well screen clogging and some other issues.Inorganic Geochemists are apt to work in consulting companies on environmental projects such metal releases to ground water, and mining related issue such as acid mine drainage and closure projects. So there is some diversity but I fear the field may slowly decline as these sites get cleaned up; A lot of civil engineers also get into those issues even though many are poor chemists. I work with a lot of hydrogeologists also and often I would class them as chemophobic (they avoid chemistry completely).I am old enough not to worry about the decline in the industry, and I work for myself. Other fields an inorganic geochemist could get involved with would include carbon sequestration, and nuclear waste disposal. Microbiology and geochemical processes are becoming more appreciated and probably drive a lot of the processes that we identify as inorganic. MIcrobes produce a lot of enzymes that drive a lot of reactions.My training started 45 years ago and about 35 years I went back for my Ph.D. and that was more or less classical Aqueous Chemistry. I was dealing with nuclear waste disposal and surface complexation modeling. My Ph.D. advisor was a student of Robert Garrrels (he was at Harvard University in the early 1960’s). So I still do a lot of classical thermodynamic work and modeling with programs like PHREEQC, a similar program called PhreePlot and occasionally Geochemist’s Workbench.Even if you are mainly an inorganic chemist some organic background would not hurt, particularly if you end up consulting. There are still a lot of places that are impacted by various organic chemicals; solvents, and pesticides for example.In any case you will probably travel a lot.