Deep Structure Model and Dynamics of Mud Volcanoes,Southwest Absheron Peninsula (Azerbaijan)

Abstract

Measurements have been made of gravitational field, geodetic uplift, regional horizontal tectonic movement, thermal patterns, and radioactivity in the general area of the Lokbatan mud volcano after its explosion on October 25, 2001, as well as in the crater itself. In addition, geochemical measurements of vitrinite reflectance with depth have been done and isotopic variations of methane and ethane are also made available. This massive compendium of information represents the first time such a detailed investigation has been possible of the deep structural effects of a mud volcano and also of the sources of mud and gas at outflow time. The data are integrated into a combined picture that shows the roots of both the mud outflow and of the gas causing the flaming eruption are at several kilometres depth into the sedimentary pile. The overall behaviour is best served by a model in which a relatively thin jet of liquefied mud is extruded from depth due to action of the varying tectonic stresses in the region, as adduced from the global positioning system (GPS) tectonic movement data. The variation of Bouguer gravity across a profile including the Lokbatan mud volcano, and combined with the geodetic vertical motion immediately after and long after (10 months) the explosion, confirms this basic model. The focusing of heat flux around the volcano prior to the explosion, and the thermal measurements made with time after the explosion both in the crater and also in the immediate vicinity of the Lokbatan volcano, are in accord with a thin hot jet model in which liquefied mud, with entrained gas from deeper in the sediments, rises through a neck region and, due to the Rayleigh–Bernard convective instability, produces a high temperature region. The geochemical evidence, showing low vitrinite maturity (<0.6%) to a depth of around 6 km, also indicates production of oil and gas from greater depths, as do the isotopic carbon measurements of methane and ethane in the unburnt gases. In short, it would seem that tectonic “squeezing” of a low-strength plastic mud layer from depth through a narrow vent with entrained gas and mud is the primary driver for mud volcano explosions. In the general regional, approximately linearly arranged lines of mud volcanoes, with their apparent focus centred on Shemakha from where the lines fan out, is also a strong indication of the basic tectonic origin. The combination of a rapidly filled sedimentary region, with unconsolidated (or deconsolidated) muds occupying a domain at several kilometre depth, and bracketed above and below by more competent formations, together with the active horizontal stress variations as measured by the GPS network, together form the basis for the spectacular mud volcano effects in this part of Azerbaijan.

Keywords

Mud Volcanoes Azerbaijan Deep Structure Dynamics Thermal Geochemical

References

Dadashev

A. A.

(1985). Peculiarities of carbon isotope composition of hydrocarbons on the western flank of the South Caspian Basin. Abstract of Ph.D dissertation. Moscow. VNIIYAG. 25 p.

Dadashev

F. G.

(1963). Hydrocarbon gases of Azerbaijan mud volcanoes. Baku. Azerneshr. 66 p. (in Russian).

Gorin

V. A.

and Buniat-Zade

Z. A.

(1968). Deep faulting belts of the crust and the oil and gas volcanism. Izv. Akad. Nauk Azerb. SSR, Ser. Nauk Zemle, no. 2, 11–17. (in Russian).

Gubkin

I. M.

and Fedorov

S. F.

(1938). Gryazevye vulkany Sovetskogo Soyuza i ikh svyaz's genezisom neftyanykh mestorozhdenii Krymsko-Kavkazskoi geologicheskoi provintsii (Mud volcanoes of the Soviet Union and their implications for the genesis of oil fields in the Crimea-Caucasus geological province). Moscow, AN SSSR.

Guliev

Ismet

A. R.

and Djafarova

P. S.

(1996). Inert components in gases of deposits of Guneshly, Azeri, and Chirag. Azerbaijan Oil Industry. no 9, 7–11.

Guliev

I. S.

and Kadirov

F. A.

(2000). A mechanism of intrastratal migration of hydrocarbons. Transactions (Doklady) of the Russian Academy of Sciences/Earth Science Section. 373, no. 6, August-September, 941–944.

Guliev

I. S.

Kadirov

F. A.

Reilinger

R. E.

Gasanov

R. I.

and Mamedov

A. R.

(2002). Active tectonics in Azerbaijan based on geodetic, gravimetric, and seismic data; Transactions (Doklady) of the Russian Academy of Sciences/Earth Science Section. 383, no. 2, 174–177.

Herring

T. A.

(1998). GLOBK: Global Kalman Filter VLBI and GPS Analysis Program. Version 4.1, Cambridge: Mass. Inst. Technol.

Ivanov

S. N.

(1970). The ultimate depth of open cracks and the hydrodynamic regionalization of the crust. Ezhegodnik. Osnovnye rezul'taty rabot 1969 g (Yearbook. Main Results of Research in 1969), Sverdlovsk: Inst. Geol. Geochem. UO AN SSSR, 212–233.

10.

Kadirov

F. A.

and Kadyrov

A. H.

(1990). The possibility of the thermal convection in the sedimentary layers of Azerbaijan. Revue Academy of Sciences of Azerbaijan, Earth Sciences. Publishing House ELM, Baku (in Russian).

11.

Kadirov

F. A.

(2000). Gravity field and models of deep structure of Azerbaijan. Baku, Publishers, ‘Nafta-Press’, 112 p. (in Russian).

12.

Karakin

A. V.

Karakin

S. A.

and Kambarova

G. N.

(2001). Geological-geophysical analysis of mud volcanism regions. Izvestia, Physics of the Solid Earth 37, no 8, 684–692, MAIK “Nauka/Interperiodika”.

13.

King

R. W.

and Bock

(1998). Documentation for the GAMIT analysis software. Release 9.7, Cambridge: Mass. Inst. Technol.

14.

Kropotkin

P. N.

and Valyaev

B. M.

(1981). Geodynamics of the mud volcanism activity in relation to the oil and gas content / geological and geochemical foundations of the prospecting for oil and gas. Kiev: Naukova Dumka, 249 p. (in Russian).

15.

Lerche

and Bagirov

, (1999). Impact of natural hazards on oil and gas extraction. Kluwer Academic/Plenum Publishers, New York, 353 p.

16.

Lerche

Mukhtarov

A. Sh.

Kadirov

F. A.

and Feyzullayev

A. A.

(2002). Thermal Measurements at Lokbatan Mud Volcano: Changes after Explosion of 25 October 2001, Azerbaijan Geology (in press).

17.

Mekhtiev

Sh. F.

and Khalilov

E. N.

(1987). Volcanoes and geodynamics, Priroda, no. 5, 47–49.

18.

Mukhtarov

A. Sh

. (2002). Energy transfer and thermal regime in the mud volcanoes channel. Energy Explor. Exploit. (in press).

19.

Mukhtarov

A. Sh.

and Adigezalov

N. Z.

(1997). Thermal regime of mud volcanoes in eastern Azerbaijan. Proceedings of Geology Institute 26, 221–228 (in Russian).

20.

Mukhtarov

A. Sh.

Kadirov

F. A.

Guliyev

I. S.

and Lerche

(2002). Temperature evolution in the Lokbatan mud volcano crater (Azerbaijan) after the eruption of 25 October 2001. Energy Explor. Exploit. 21, 187–208.

21.

Oral

(1994). Global Positioning System (GPS) measurements in Turkey (1988–1992): Kinematics of the Africa–Arabia–Eurasia Plate collision zone, PhD. Thesis, Cambridge: Mass. Inst. Technol.

22.

Peive

A.V.

(1956). Sedimentation, folding, magmatism, and mineral deposits in relation to deep faults. Izv. Akad. Nauk SSSR, Ser. Geol., no. 3, 57–71.

23.

Rakhmanov

R. R.

(1987). Mud volcanoes and their implications for the oil and gas content of deep formations, Moscow: Nedra.

24.

Salaev

G. G.

and Kastryulin

N. S.

(1977). Implications of tectonic fractures for the formation of oil and gas accumulations in Kobystan, Baku, Elm (in Russian).

25.

Stach

Mackowsky

M. T.

Taylor

G. H.

Chandra

Teichmuller

and Teichmuller

(1982). Coal Petrology, 2nd Edition, Elsevier, Berlin, 428 p.

26.

Stahl

W. J.

(1977). Carbon and nitrogen isotopes in hydrocarbon research and exploration. Chem. Geol. 20, 121–149.

27.

Sukharev

G. M.

Taranukha

Yu. K.

and Vlasova

S. P.

(1969). Heat flow from Azerbaijan. Soviet Geology 8, 146–153. (in Russian).

28.

Trubitsyn

V. P.

Kadirov

F. A.

and Kadyrov

A. H.

(1998). Influence of the thermal convection in a viscous intermediate layer on distribution of temperature of a multilayer sedimentary complex, Revue Academy of Sciences of Azerbaijan. Earth sciences. Publishing House of Azerbaijan Academy of Sciences, Baku, no. 1. pp. 64–68 (in Russian).

29.

Trubitsyn

V. P.

Zasepina

O. E.

and Kadyrov

A. G.

(1992). Thermal evolution of the layered environment with an intermediate viscous layer, Izvestiya AS Russia. Physics of the Solid Earth 8, 3–11 (in Russian).

30.

Valyaev

B. M.

(1985). Isotope image of the mud volcano gases. Moscow, Nauka, pp. 72–78.

31.

Vassoevich

H. B.

(1986). Geochemistry of organic matter and origin of oil, Selected Proceedings. Moscow, Nauka 336 p.

32.

Weber

V. V.

(1939). Natural gases of USSR. Moscow. ONTI. 212 p.

33.

Wavrek

Collister

Curtiss

Quick

Guliev

and Feyzullayev

(1996). Novel application of geochemical inversion to derive generation/expulsion kinetic parameters for the South Caspian Petroleum Systems, Azerbaijan. AAPG/ASPG Research Symposium “Oil and Gas Petroleum Systems in Rapidly Subsiding Basins” October 6–9, Baku, Azerbaijan.

34.

Yakubov

A. A.

Ali-Zade

A. A.

and Rakhmanov

R. R.

(1974). Catalog of recorded eruptions of mud volcanoes in Azerbaijan over the period from 1810 through 1974, Baku, (in Russian).

35.

Yakubov

A. A.

Ali-Zade

A. A.

and Zeynalov

M. M.

(eds.). (1971). Mud volcanoes of the Azerbaijan SSR. Atlas. Academy of Sciences of the Azerbaijan SSR, Baku (in Russian).

36.

Yakubov

A. A.

and Atakishiyev

I. S.

(1973). Geothermal researches of oil-gas fields of Apsheron, Baku: Azerneshr. 88 p. (in Russian).

37.

Yakubov

A. A.

Gorin

V. A.

and Buniat-Zade

Z. A.

(1972). Mud volcanism, geologiya SSSR. T. 47. Azerb. SSR (Geology of the USSR. Vol. 47: Azerbaijan SSR), Moscow, Nedra, pp. 390–403 (in Russian).