Open Journal of Geology, 2013, 3, 77-80
doi:10.4236/ojg.2013.32B016 Published Online April 2013 (http://www.scirp.org/journal/ojg)
Using Petrophysica l P roper ti e s of Volcanic Rocks in the
Interpretation of Geophysical Data
(Volcano Ebeko, Kuril Islands)
A. Ya. Shevko1, M. P. Gora1, N. A. Golikov2, G. L. Panin2, E. P. Bessonova3
1Siberian Branch of Russian Academy of Sciences, V S Sobolev Institute of Geology and Mineralogy, Novosibirsk, Russia
2Siberian Branch of Russian Academy of Sciences, Trofimuk Institute of Petroleum Geology and Gejphysics,
Novosibirsk, Russia
3Tomsk Polytechnic University, Russia
Received 2013
ABSTRACT
Petrophysical properties of volcanic rocks were investigated on the North-Eastern fumarolic field of the volcano Ebeko.
The attempt is made to use this data in order to interpret the geo-electrical cross sections of the fumarolic field subsur-
face space.
Keywords: Petrophysical Property; Electrical Resistivity; Electrical Tomogpaphy; Fumarolic Field; Volcano Ebeko;,
the Kuril Islands
1. Introduction
The study of thermal fields subsurface space on active
volcanoes is only possible using non-destructive methods.
This is due to the fact that any intervention (drilling, lay-
ing of test pits) entails a violation of the natural equilib-
rium of natural systems. The use of geophysical methods
(electrical resistivity tomography) gives the possibility to
reveal the inner structure of thermal fields and to identify
the shapes of the underground reservoirs and feed chan-
nels [1]. The complex of petrophysical methods allows to
fill physicochemical model of the volcano-hydrothermal
system with real data [2,3]. In addition, the petrophysical
properties of rocks can be used for the interpretation of
the cross sections obtained by the electrical resistivity
tomography method.
2. Object of the Research
Active volcano Ebeko is located in the Northern part of
the island of Paramushir (Kuril Islands). At present the
volcano keeps a high activity. It consists in periodic
emissions of resurgent ashes, ongoing activities of fu-
maroles and hot springs [4,5]. Solutions of the boiling
pools and hot springs on the fumarolic field are presented
acid or hyper-acid waters (pH values range from - 0.4 to
1.7). The temperatures of the thermal solutions range
from 41℃ to 92℃. The mineralization range is from 2.7
to 20 g/L. The major anions of the solutions are chlorides
and sulfates in different proportions and concentrations.
The concentrations of chlorides vary from several fold to
three orders of magnitude. The microelement concentra-
tions also varied widely in the different thermal solutions
[6].
The field samplings were carried out from different
parts of the North-Eastern fumarolic field of the volcano
Ebeko. The samples of unaltered and hydrothermally altered
volcanic rocks were collected. Metasomatic alteration of
volcanogenic rocks are represented by replacement
phenocrysts and basis of the rocks by new growth miner-
als. Partial alteration plagioclase is the initial stage of
metasomatism. In the further process of changes captures
as porphyric crystals, so the groundmass of the volcanites
with the formation of argillizated rocks.
3. Analytical Methods
Study of the petrophysical properties of the samples was
performed according to standard and generally accepted
method, modified taking into account the fact that part of
the samples had a cavernous porosity. It was carried out
the following analyses: porosity method of water satura-
tion; the volume and mineral density; the absolute per-
meability to gas. Specific electric resistivity was meas-
ured by two techniques: resistivity with natural saturation
and resistivity in artificial saturation of the solution with
a concentration of 6 g/l was determined by standard
methods in atmospheric conditions; a change of resistiv-

A. Ya. SHEVKO ET AL.
78
ity with increase of temperature up to 70℃ was carried
out at a facility for the simulation of the formation of
conditions for effective pressure 8МПа. All researches
were performed in the laboratory of experimental seis-
mology of IPGG of the SB RAS.
Eelectrical resistivity tomography of the volcano Ebeco
North-Eastern fumarolic field was carried out on the
equipment of the «Rock-48» using two cables, the total
number of electrodes which was 48. Step between the
electrodes was equal to 5 m. In this case a maximum
spacing of the installation was about 235 m and maxi-
mum depth sensing was about 40 m. A system of moni-
toring of Schlumberger was used in all cases. The pro-
files were oriented parallel to the slope to reduce the dis-
tortions caused by the influence of the relief [7].
4. Results and Discussion
Volcano Ebeco, according to our field investigation,
consists mainly of flows andesites, less andesite-basalts
and basalts. Thus, the samples in varying degrees altered
andesites, selected on the North-Eastern fumarolic field,
is the representative and may characterize the cross sec-
tion structure of the thermal field. Some results of petro-
physical studies of these rocks are given in the Table 1.
As you can see, tuff breccia has the minimum values
electrical resistivity and maximum coefficients of poros-
ity and permeability in comparison with the other sur-
veyed rocks. The coefficient of the porosity of andesites
varies from 10 to 27 %, and the permeability of the rocks
by this is changed to 2 orders of magnitude (Figure 1).
On the figures, in addition to the points corresponding to
the characteristics of the volcano Ebeco rocks, for com-
parison are given points for the rocks of Golovnin vol-
cano (Kunashir island, Kuril islands). Previously, we
carried out a study of petrophysical properties in combi-
nation with petrological description of volcanic rocks of
Golovnin caldera to compare basic parameters with tex-
ture-structural characteristics of rocks [8].
Table 1. Petrophysical property of the volcano Ebeko rocks.
Specimen Rock
Permeability
coefficient,
mD
Porosity
coefficient,
%
Electrical
resistivity,
om*m, 6 g/l
PR-117 Andesite 1 22,2 57,1
PR-118 Andesite 126 27,8 39,5
PR-119 Tuff breccia 183 33,8 14,8
PR-120 Andesite 1,22 18,3 27,7
PR-121 Andesite 162 20,7 60,8
PR-122 Argillizated rock 0,22 22,7 27,0
PR-123 Argillizated rock 10,9 17,7 89,9
PR-124 Andesite 1,18 22,7 63,1
PR-125 Andesite 2,53 10,9 124,6
It is established, that effusive and tuffaceous rocks
form a discrete group on its petrophysical properties. [9].
According to our data, tuffs and tuff breccias are the
most high porosity and permeability. Nevertheless prop-
erties as effusive rocks so and tufaceous rocks are
changed in one trend (Figure 2).
Comparison of petrophysical characteristics of various
degree altered effusive and clastic (tuff, tuff breccia)
rocks has shown, that with increase in degree of rocks
alteration up to formation propylites, argillizated rocks
and secondary quartzites their properties do not change
linearly. The dependence of the petrophysical properties
from the degree of weathering is more complicated. De-
spite this, it can be seen that there is an inverse correla-
tion between the porosity and specific electric resistivity,
which is characteristic for volcanic rocks on the thermal
fields of active volcanoes (see Figure 2).
Figure 1. The permeability coefficient versus porosity coef-
ficient for the rocks of volcanoes Ebeco (1-3) and Golovnin
(4-6). 1, 4 - tuff, tuff breccia; 2 - andesites; 3, 6 - argillizated
rocks; 5 - andesidacites.
Figure 2. The specific electrical resistivity versus porosity
coefficient for rocks of the volcanoes Ebeco and Golovnin.
Legend look at figure 1.

A. Ya. SHEVKO ET AL. 79
The cross sections for the North-East fumarolic field
were constructed on data of the electrical resistivity to-
mography (Figure 3). On the figure structure of the sub-
surface space, the supply system of pools and fumaroles
is clearly visible. Specific electric resistance of rocks in
the sections is varied in the limits of 0.5 - 63 Ohm·m.
The lowest resistivity is observed in areas of fractured
zones of transport of the thermal solution. The value of
electrical resistivity for them is determined only by the
ionic conductivity of the circulating solution and is equal
to 0.43 - 1.4 Ohm·m. Increase electrical resistivity is
caused, probably, with decrease in porosity of the rocks,
and consequently, with their water saturation. Maximum
values electrical resistivity are observed at the sites of
fumarole outputs. Here the rocks are saturated with solu-
tions in the least degree and the electrical resistivity is
equal to 40-63 Ohm*m.
Figure 3. Geo-electrical cross sections for volcano Ebeco
North-Eastern fumarolic field [7].
Figure 4. The specific electrical resistance versus tempera-
ture for rocks of the volcanoe Ebeco.
Comparing resistivity which was obtained with the
electrical resistivity tomography and resistivity which
was measured for the individual specimens, we can use
other petrophysical characteristics of this sample (see
Table 1) for the interpretation of the cross sections of the
fumarolic field subsurface space. The decrease of the
resistivity on profiles electrical resistivity tomography
can be attributed to a number of factors, namely: the in-
crease in porosity (see Figure 2); increase of mineraliza-
tion of solutions which fill the pores; and increase in the
temperature. In Figure 4 you can see a significant de-
crease of the specific electric resistance, measured in
laboratory conditions, with growth of temperature. The
temperature of the rocks on the surface during the
sounding was equal to 29 - 46 degrees C, and at the depth
of 1.5 m (in test pits) there was increase of temperature
in average of 33 degrees.
5. Conclusions
The combination of geological, geophysical and petro-
physical investigations are of great importance in the
study of the structure of the subsurface space thermal
fields on active volcanoes. In the interpretation of geo-
physical data, we can make conclusions about the com-
position and the texture of the rocks, which compose the
cross section.
6. Acknowledgements
The authors thank to Professor S. B. Bortnikova, which
has gathered around himself geologists of various spe-
cialties and is the inspirer of a comprehensive approach
to the research of active volcanoes of the Kuril Islands,
and to Deputy Director of IPGG of the SB RAS I. N.
Eltsov for support at all stages of the expedition and desk
works.
REFERENCES
[1] E. P. Bessonova, S. B. Bortnikova M. P. Gora, Yu. A.
Manstein, A. Ya. Shevko, G. L. Panin and A. K. Man-
stein, “Geochemical and Geo-Electrical Study of Mud
Pools at the Mutnovsky Volcano (South Kamchatka, Rus-
sia): Behavior of Elements, Structures of Feeding Chan-
nels and a Model of Origin,” Applied Geoche mistry, Vol.
27, No. 9, 2012, pp. 1829-1843.
[2] E. P. Bessonova, M. P. Gora, A. Ya. Shevko, K. V.
Chudnenko and V. K. Cherepanova, “Estimation of
Change Dynamics of Physical Characteristics of Section
Hydrothermal Altered on the Nonisothermal Phys-
ico-Chemical Modeling (by the Example of the Mut-
novsky),” Izvestiya, Physics of the Solid Earth, No. 6,
2011, pp. 57-68.
[3] A. Ya. Shevko, M. P. Gora, E. P. Bessonova and N. A.
Golikov, “Using Petrophysical Properties of Volcano-
genic Rocks for the Purposes of the Physico-Chemical

A. Ya. SHEVKO ET AL.
80
Modeling,” Modern Problems of Magmatism and Meta-
morphism, Materials of All-Russian Conference Devoted
to the 150-anniversary of academician F. Yu. Levin-
son-Lessing and the 100 anniversary of Professor G. M.
Sarantchina, St. Petersburg, Vol. 2, 2012, pp. 347-349.
[4] Т. А. Коtenkо, L. V. Коtеnkо, Е. I. Sandimirova, V. N.
Shаpаr' and I. F. Тimоfееvа, “Eruption Activity of Ebeko
volcano (Papamushir I.) in 2010-2011,” Bulletin of Kam-
chatka regional association «Educational-scientific cen-
ter. Earth sciences, Vol. 19, No. 1, 2011, pp. 160-167.
[5] I. V. Melekescev, V. N. Dvigalo, V. Yu. Kirianov, A. V.
Kurbatov and I. A. Nesmachnii, “Volcano Эбеко (Kuril
Islands): History of Eruptive Activity and Future Vol-
canic Hazards. Part II,” Journal of Volcanology and Seis-
mology, No. 4, 1993, pp. 24-42.
[6] S. B. Bortnikova, E. P. Bessonova, L. B. Trofimova, T. A.
Kotenko and I. V. Nikolaeva, “Hydrogeochemistry of
Thermal Springs on Ebeko Volcano, Paramushir,” Jour-
nal of Volcanology and Seismology, No. 1, 2006, pp.
39-51.
[7] G. L. Panin, T. A. Kotenko, L. V. Kotenko and U. G.
Karin, “Geophysical and geochemical investigations of
thermal fields of Ebeco volcano (Paramushir Island),”
Lithosphere, No. 3, 2010, pp. 171-176.
[8] N. A. Golikov, A. Ya. Shevko, M. P. Gora and E. P.
Bessonova, “Petrophisical properties of volcanogenic
rocks of different degree of hydrothermal change in areas
of the active volcanism (on the example of Golovnin vol-
cano),” Interexpo Geo-Siberia-2011: 8th International
specialized exhibition and scientific congress. Mineral
Resources Management. Mining. New Trends and Tech-
nologies for Exploration and Prospecting of Mineral Re-
sources, Novosibirsk, Vol. 1, 2012, pp. 183-187.
[9] J. V. Frolova, V. M. Ladygin and S. N. Rychagov,
“Regularities of Transformation of Structure and Proper-
ties of Volcanogenic Rocks in Hydrothermal-Magmatic
Systems of Kuril-Kamchatka Island arc,” Moscow Uni-
versity Geology Bulletin, No. 6, 2011, pp. 52-61.