Geochemistry of mercury

Typical mercury content of common rocks (after Jonasson and Boyle, 1972) 

It is considered that in the primary (hypogene) environment, Hg is transported principally as complexes in hydrothermal solutions, although the relative importance of sulphide, bisulphide, chloride, hydroxy and organic complexes remains controversial (Bames et al., 1967 Barnes, 1979). At temperatures of over about 200°C vapour-phase transport may also be important, but very little evidence exists to indicate the possible scale and practical significance of any such transport (Krauskopf, 1964 Bames et al., 1967 Khodakovsky et al., 1975). 

The main natural source of Hg in the secondary environment is believed to be the oxidation of sulphide minerals (Saukov, 1946 Williston, 1964 Ryall, 1979b), although 

In its chemical properties Hg differs distinctly from Zn, with which it is commonly associated in the primary environment. Whereas Hg has fields of stability for the zero, one and two valence states, Zn in the natural regime exists only as Zn (II). In addition to Eh and pH, Hg phase stability is dependent on the concentration of the halide and sulphur species. 

Within soils Hg can exist in the ionic or associated forms, HgCl, Hg(OH)2 and HgCb, as elemental Hg and within various solid phases. The presence of gas-phase Hg in soil is therefore understandable, although it is evident that under conditions of equilibrium the level of free Hg in aerated chloride-containing soil will be low. It can be expected that similar equilibrium conditions apply to the aqueous solutions derived from sulphide oxidation, since the sulphate ion does not interact strongly with the several Hg species. 

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Roulet M, Lucotte M, Saint-Aubin A, Tran S, Rheault I, Farella N, de Jesus da Silva E, Dezencourt J, Sousa Passes CJ, Santos Soares G, Guimaraes JR, Mergler D, Amorim M. 1998. The geochemistry of mercury in central Amazonian soils developed on the Alter-do-Chao formation of the lower Tapajos River valley, Para state, Brazil. Sci Total Environ 223 1-24. 

Chang, L.W. 1979. Pathological effects of mercury poisoning. Pages 519-580 in J.O. Nriagu (ed.). The Bio geochemistry of Mercury in the Environment. Elsevier/North-Holland Biomedical Press, NY. 

Roulet, M. and M. Lucotte. 1995. Geochemistry of mercury in pristine and flooded ferralitic soils of a tropical rain forest in French Guiana, South America. Water Air Soil Pollut. 80 1079-1088. 

Smith CN, Kesler SE, Blum JD, Rytuba JR (2008) Isotope geochemistry of mercury in source rocks, mineral deposits and spring deposits of the CaUfomia Coast Ranges, USA. Earth Planet Sci Lett 269 398-406... 

Open Ocean Mercury Determinations. In our initial studies concerned with the marine geochemistry of mercury, we obtained open ocean smrface samples by hand from a small work boat away from any adverse influence of the oceanographic research vessel. The concentrations of mercury in the open-ocean surface waters (western Sargasso Sea) were small (ca. 10 ng/1.) and rather imiformly distributed (26). However, to collect seawater to determine the concentrations of mercury at other depths, we needed an artifact-free sampling procedure. 

Elinson, M.M., Pashkov, Y.N., Agababov, G.M. and Ignatiev, I.B., 1970. Research on gas aureoles around copper-molybdenum ore bodies. In Outline of the Geochemistry of Mercury, Molybdenum and Sulphur in the Hydrothermal Process. Nauka Publ., Moscow, pp. 217-236 (in Russian). 

James, C.H., 1962. A review of the geochemistry of mercury and its application to geochemical prospecting. Tech. Comm. No. 41, Geochemical Prospecting Research Centre, Imp. Coll. Sci. Tech., London, 42 pp. 

Saukov, A.A., 1946. Geochemistry of mercury. Trans. Inst. Geol. Sci., Acad. Sci. USSR, Issue 78, Series Mineralogy and Geochemistry, 17,128 pp. 

Warren, H.V., Delavault, R.E. and Barakso, J., 1966. Some observations on the geochemistry of mercury as applied to prospecting. Econ. Geol., 61 1010-1028. 

Rae, J.E. (1980) The geochemistry of mercury in estuarine mixing and sedimentation. PhD Thesis, University of Lancaster, Lancaster, UK. 

Fleischer, Miclael, 1970, Summary of the Literature on the Inorganic Geochemistry of Mercury, In Mercury in the Environment, U.S.G.S. Prof. Paper 713, pp. 6-13. 

Fitzgerald WE, Lamborg CH (2005) Geochemistry of mercury in the environment. In Holland HD, Turekian KK (eds) Treatise on geochemistry, environmental geochemistry. Elsevier, San Diego, USA, pp 108-148... 

Garcia-Rico L, Valenzuela-Rodriguez M, Jrua-Marini ME (2006) Geochemistry of mercury in sediments of oyster areas in Sonora, Mexico. Mar Pollut Bull 52 453-458 Garcia-Rico L, Tejeda-Valenzuela L, Burgos-Hemandez A (2010) Seasonal variations in the concentrations of metals in Cmssostrea corteziensis from Sonora, Mexico. Bull Environ Contam Toxicol 85 209-213... 

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