PATTERNS OF MERCURY DISTRIBUTION IN GROUNDWATER OF THE KOLYVAN–TOMSK ZONE

P. A. UDODOV, P. N. PARSHIN, Yu. G. KOPYLOVA

(Presented by the scientific seminar of the Problem Geological Laboratory of TPI)

The regional hydrogeochemical investigations carried out by the Problem Geological Laboratory of TPI within the Kolyvan–Tomsk folded zone have made it possible to clarify many questions of the geology and metallogeny of this region. Some of these questions have been reflected in published works [14, 15, 16]. In particular, these works have dealt with the overall prospects of the region for ore minerals, demonstrated the effectiveness of the hydrogeochemical method in tracing zones of rupture disturbances, and also shown the presence of microcomponents in soils and groundwater. Subsequent works confirm these conclusions. In addition, new materials are appearing that make it possible to use hydrogeological and hydrogeochemical data more fully for solving various geological and hydrogeological problems. Thus, for example, the results concerning the spatial distribution of mercury contents in the groundwater of the region, and the regularities of the interrelation of this factor with hydrogeological and structural conditions, are of interest; the authors devote this brief communication to this subject.

We shall not dwell here on the geological characteristics of the region. Such data, in addition to the literature cited above, may be found in the works of M. K. Korovin [4], A. V. Tyzhnov [13], A. I. Gusev [2], B. F. Speransky [10], and others. The most complete structural zoning of the Kolyvan–Tomsk folded zone is given in the works of V. V. Vdovin [1] and A. L. Matveevskaya [7, 8].

In the eastern part of the region, in its northeastern structures, groundwater containing mercury is traced by springs in the basins of the Kuerbak, Kirgizla, Omutnaya, Berezovaya, and Tashma rivers. These springs, as a rule, are confined to sublatitudinal sections of river valleys (across the strike of the principal structural elements of the region). Such a combination is probably due to the connection of spring outlets with a system of transverse rupture disturbances. However, the entire aggregate of individual groups of mercury-bearing springs corresponds to systems of submeridional rupture disturbances of the Shcherbakov crushing-zone type. A considerable portion of these points is confined to the system of rupture disturbances bounding the Ulanovka depression. The latter, evidently, developed as a result of the manifestation of such disturbances.

Farther south, in the eastern part of the region, mercury in groundwater is manifested most clearly along the marginal zones of the Bugotak hor—

the stanticline and partly within the limits of the Chem structure. Moreover, here one can observe a certain relationship between mercury occurrences and the marginal parts of a younger structure—the Doronino depression (but less distinctly than is observed for the Ulanovo depression in the northeastern part of the region).

Thus, along the junction of the Kolyvan–Tomsk zone with the structures of the Kuznetsk Alatau and Salair (especially in places where superimposed younger structures developed), the most frequent occurrence of mercury in groundwater and cinnabar in concentrates is observed.

Within the structures of the Kolyvan–Tomsk folded zone itself, some points of mercury occurrence in waters and cinnabar in concentrates also tend toward the boundaries of the junction of different structural elements. In particular, they are apparently associated with faults that bound the Bugotak horst-anticline and its possible continuation—the Karakan uplift (the latter stands out especially clearly by the occurrence of mercury in waters and cinnabar in concentrates).

In the western part of the region (in the area where the flyschoid deposits of the main trough and the Novosibirsk granitoid complex are developed), fairly isolated areas occur with a mercury and, possibly, antimony–mercury complex of elements in groundwater, often accompanied by the occurrence of cinnabar in concentrates.

Thus, in the area of the Novosibirsk granitoid massifs, mercury is recorded both in water concentrates and in concentrates in the middle reaches of the rivers Barlak, Kamenka, Ora, and Oyash (Table 2). Possibly, here mercury is localized along small disturbances in sedimentary formations near the contacts of granitoid formations (apparently, their latest varieties).

Farther north, in the Pritomye area (the basins of the Sosnovka and Tugoyakovka rivers) (Table 2), a number of areas are outlined with mercury occurring in groundwater and in rocks. Here the occurrence of mercury in waters spatially coincides with the Kolarovo–Semiluzhki crushing zone [9] and, probably, is controlled by the development of a system of post-folded submeridional (along the line of the villages Melkovo—Kolarovo—Semiluzhki) and sublatitudinal (of the Tugoyakovka-zone type) faults. The maximum mercury contents in the waters of this area are observed on its southern margin, in the basin of the Sosnovka River (Table 2), and the minimum contents—in the northern part, in the area of the village of Semiluzhki. At the latter point, antimony mineralization is known, the mercury content in which is detected only by chemical analysis (up to 0.0005%); individual grains of cinnabar are occasionally found in concentrates. Thus, one may expect a certain specialization of the outlined antimony–mercury mineralization within the Kolarovo–Semiluzhki zone: essentially mercury-bearing in the south and essentially antimony-bearing in the north.

Let us cite published data on the mercury content in groundwater of some mercury deposits of the USSR (Table 1).

The distribution of maximum mercury contents in groundwater by individual areas of the region is summarized in Table 2.

Comparison of the two tables presented shows that higher mercury contents are recorded in the waters of our region than in the groundwater of known mercury deposits. The discrepancy in contents has remained unexplained up to the present. Possibly, it is due to differences in the methods used for determining mercury in different types of waters and in different geochemical settings. This requires detailed work to clarify all the facts presented.

The occurrence of mercury in groundwater in the region described often

coincides with zones of polymetallic mineralization (the Tashma, Omutnaya, and Tugozhovka rivers, the Izdrevaya River, the villages of Baranovo and Ogneva Zaimka). It is possible that in some cases mercury is a companion of polymetallic ore formation, as noted by A. A. Saukov [11] for other regions. However, a certain separation, in the general plan of the region, of mercury mineralization from polymetallic mineralization, and the high concentrations of mercury in groundwater, indicate the possible independent manifestation of mercury mineralization on a rather significant scale.

Table 1

Table 2

It is probable that there is also a superposition of mercury (or antimony–mercury) mineralization upon certain zones of earlier polymetallic mineralization, in the process of renewal of the latter by later tectonic movements (the Tugozhovka River, the village of Baranovo).

Since antimony–mercury mineralization is considered low-temperature and later relative to polymetallic mineralization, the impression is created that a rather significant denudation truncation occurred between the manifestations of polymetallic and antimony–mercury mineralization.

Thus, the boundaries of the main structural elements of the region, outlined by V. V. Vdovin [1], A. D. Matveevskaya [7, 8], and other researchers, are often manifested in the mercury content of waters. The fact of mercury localization along certain disjunctive faults that border younger (Mesozoic) depressions superimposed on the Paleozoic basement can apparently be used in deciphering—

dating the time of manifestation of mercury mineralization in the region. Since the lowermost members of the sediments filling these depressions are of Late Jurassic age, it may be assumed that this age is also the lower boundary of the manifestation of mercury mineralization. This agrees with the conclusion of V. A. Khakhlov and L. A. Ragozin [17] on the Mesozoic age of cinnabar mineralization in the Tomsk area. A. M. Kuzmin [6] considers the Semiluzhenskoye stibnite occurrence to be later than the Upper Paleozoic gold-quartz mineralization. V. A. Kuznetsov [5] regards the mercury mineralization in the Altai-Sayan region as Mesozoic.

In conclusion, we note that in the region under discussion one may expect the presence of favorable structural conditions for significant localization of mercury mineralization.

It is possible that thrust forms of disjunctive disturbances were the most favorable for the localization of mercury, as is the case at many mercury deposits of the USSR.

Thrust forms of disjunctive disturbances are developed throughout the region as follows. In the northern part of the region the amplitude of horizontal displacement reaches hundreds of meters (in the area of the Kamensky limestone along the Shcherbak River, according to M. P. Nagorsky [9]—up to 800 m). Farther south, toward the place where the Paleozoic structures are crossed by the latitudinal course of the Tom River (the Kemerovo—Yurga sector), the presence of thrust forms is still disputed and has not been clearly established. At least, significant amplitudes of displacement are apparently not to be expected here. Still farther south, in the area of the boundaries of the Bugotak horstanticline, according to mapping work by the Novosibirsk Geological Administration, the disjunctive disturbances have a reverse-fault character, with steep angles of dip (the Chemsky and Kamensky faults and their subsidiary branches, and others).

The data presented indicate a greater prospectivity for mercury mineralization in the northern part of the region in comparison with its central and southern parts.

REFERENCES

1. V. V. Vdovin. Geotectonic structures of the Kolyvan-Tomsk arc. Proceedings of the Mining-Geological Institute, West Siberian Branch of the USSR Academy of Sciences, issue 15, 1956.

2. A. I. Gusev. Geological structure and mineral resources of the area of Novosibirsk. ZSGT Publishing House, Tomsk, 1934.

3. B. Z. Zautashvili. On the problem of the hydrogeochemistry of mercury (with reference to the mercury deposits of Abkhazia). Geochemistry, No. 3, 1966.

4. M. K. Korovin. A new Late Paleozoic Ob-Yenisei folded zone of Western Siberia. Proceedings of the Academy of Sciences of the USSR, geological series, No. 6, 1945.

5. V. A. Kuznetsov. Regularities in the formation and spatial distribution of mercury deposits in the Altai-Sayan folded region. In: Regularities in the Distribution of Mineral Resources, vol. I, Publishing House of the Academy of Sciences of the USSR, 1958.

6. A. M. Kuzmin. Upper Paleozoic gold mineralization in the vicinity of Tomsk. Geology of Ore Deposits, No. 2, 1961.

7. A. L. Matveevskaya. On the structure and development of the Kolyvan-Tomsk arc in the area of its junction with Salair. Proceedings of the Mining-Geological Institute, West Siberian Branch of the USSR Academy of Sciences, issue 15, 1956.

8. A. L. Matveevskaya, E. F. Ivanova. Geological structure of the southern part of the West Siberian Lowland in connection with questions of petroleum potential. Publishing House of the Academy of Sciences of the USSR, Moscow–Leningrad, 1960.

9. M. P. Nagorsky. Geological structure and principal mineral resources of Tomsk Oblast. (Explanatory note to the geological map of Tomsk Oblast.) Tomsk, 1963. TKE archives.

10. B. F. Speransky. Structures of the Paleozoic formations of the Ob-Tom interfluve. In: Collection on the Geology of Siberia, 1933.

11. A. A. Saukov. Geochemistry of mercury. Proceedings of IGEM, Academy of Sciences of the USSR, issue 78, mineralogical and geochemical series, 1946.

1. A. A. Saukov, N. Kh. Aidinyan, V. I. Vinogradov. On the question of mercury migration in the hypergenesis zone. Problems of Geochemistry, issue 70, 1962.

2. A. V. Tykhov. Materials on the stratigraphy and tectonics of the Devonian deposits of the northwestern margin of the Kuznetsk coal basin. Izv. Zap.-Sib. GRU, XI, No. 1, 1931.

3. P. A. Udodov, V. M. Matusevich. Certain features and results of hydrogeochemical investigations in semi-enclosed geological structures of Western Siberia. In: Formation and Geochemistry of Groundwaters of Siberia and the Far East. Nauka, Moscow, 1967.

4. P. A. Udodov, V. M. Matusevich. Some results of hydrogeochemical investigations in the northeastern part of the Kolyvan–Tomsk folded zone. Izv. TPI, vol. 127, 1964.

5. P. A. Udodov, V. M. Matusevich, N. V. Grigoriev. Hydrogeochemical prospecting under conditions of semi-enclosed geological structures of the Tom–Yaya interfluve. Tomsk, 1965.

6. V. A. Khakhlov, L. A. Ragozin. On cinnabar mineralization in the area of the city of Tomsk. Uch. zap. TGU, No. 4, 1946.