Ninth international conference on - Marum

88
Abstracts of posters
shells characteristic of tidal flats, but also botanical macro-remains. The primary pore spaces are almost entirely
occupied by carbonate crystals. In the carbonate precipitates various diatom tests have left moulds. In the mudflat
concretion, biogenic compounds increase in number and diversity. Some of these are also furnished with
organic coatings characteristic of biofilms. Remaining primary pore spaces as well as secondary pores are
relatively more frequent within this type of concretion. Pyrite framboids are also present occasionally.
Acknowledgements: The authors wish to thank Thomas Höpner for his support in the early phase of the project,
and R. Botz and G. Bohrmann for stimulating discussions.
Methane in water and sediments in Sevastopol Bays, Black Sea
L.V. Malakhova 1 , T.V. Malakhova 1 , V.N. Egorov 1 , S.B. Gulin 1 , Yu.G. Artemov 1
1 Institute of Biology of the Southern Seas 2, Nakhimov Av., Sevastopol, 99011, Ukraine
The purpose of study was to determine the methane content in water column and bottom sediments of the coastal
Black Sea area adjacent to Sevastopol bays (SW Crimea) where a number of shallow gas seepages have been
found during the last years. Measurements of the dissolved CH4 were carried out in water and sediments sampled
at monitoring stations shown in Fig. 1b. Also, the gas bubble samples were taken for methane analysis over the
permanently functioning seepage in summer and autumn periods (Fig. 1a)
44°40′
a)
44°35′
b)
1
Black Sea
2
ЧЕРНОЕ МОРЕ
Казачья бухта
3
4
Бухта
Омега
Камышовая бухта
5
13
14
Стрелецкая бухта
Карантинная
бухта
Fig. 1. (a) Location of gas seepages: ● – observed in 1989-1999, ▲ – observed in 2002 and 2006 [1], ▼– found
in 2007, - - - is lines of geodynamic faults. (b) – Concentrations of the dissolved methane (µl·l -1 ) in water of
Sevastopol bays area: ▌– measured in April-May 2007, – in August-September 2007.
Measurements of CH4 were carried out using the gas chromatograph HP5890 with a flame ionization detector
(FID), whose column was packed with sorbent Porapack 80-100 mesh. The concentration was calculated in
comparison with an external methane standard. According to our data, the bubble gas contains methane (C1) and
his homologous (total concentration C2+). The measured ratio of the methane and homologous has suggested its
biological origin. Concentrations of the dissolved gas in surface waters of Sevastopol area varied from 0.47 to
20.36 µl·l -1 , and in the bottom sediments – from 0.02 to 18.67 µl·cm -3 . It was found that concentrations of
methane dissolved in water column over the seepages correspond with the background level. Content of methane
12
15
17
18
7
8
▼
Sevastopol
33°20′ 33°25′ 33°35′
10
Севастопольская бухта
Южная бухта
6
Севастополь
Sevastopol
16
CH4, µk?l -1 CH4, µl·l -1
20
15
10
5
0
9