DBPapers
DOI: 10.5593/sgem2017/51/S20.067

GAS COMPOSITION OF SULPHIDE MUDS OF ANAPA DISTRICT

D. N. Garkusha, Y. A. Fedorov, R. G. Trubnik
Wednesday 13 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-08-9 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 51, 513-520 pp, DOI: 10.5593/sgem2017/51/S20.067

ABSTRACT

The results of Chembursky lake, Vityazevsky, Kiziltashsky and Bugazsky coastal salt lakes expeditionary research are observed, aimed to examine the allocation of methane and sulfur sulfide (total sulfide) according to the vertical cut of bottom sediments (sulfidic muds), and also the value of Eh and pH. pH and Eh values in the examined horizons of coastal salt lakes bottom sediments vary correspondingly in the limits from 7.33–8.06 and -198…-2.5 mV, in the Chembursky lake sediments – 7.47–7.64 и -78…+46 mV. CH4 and ΣH2S сoncentrations change correspondingly under the limits of 0.01–22.0 μg/g and 0.01–1.56 mg/g of the wet mass, with the maximum concentration of the examined reconstructed gases in the Chembursky lake. In the examined coastal salt lakes sulfide sediments the process of sulfide reduction significantly dominates over the process of methane genesis, at the same time in the Chembursky lake sediments, under the anthropogenic influence of Anapa district, together with the active sulfide reduction the process of intensive methane genesis is observed, that results in the occurrence of high concentrations of both ΣH2S and CH4, and also in the increased values of the sulfurization coefficient (the proportion of CH4/H2S contained). The simultaneous decreasing of CH4 and ΣH2S concentrations and Eh increasing in the bottom sediments is stated as following: black or dark-grey silt (muds) → mixed sandy-clay sediments → sand sediments → clays.

Keywords: methane, total sulfide, Eh, pH, mud, bottom sediments, marine sulfide lakes.