Gold-Bearing Listvenites: A New Type of Mineralization in the Northern Kuznetsk Alatau
Abstract Generated abstract
This paper describes gold-bearing listvenites associated with hyperbasites in the northern Kuznetsk Alatau and argues that they represent a promising type of gold mineralization for the region. On the basis of geological, petrographic, mineralogical, chemical, and material-balance observations, it distinguishes ortholistvenites formed from ultrabasic rocks and epilistvenites formed from amphibole schists, and reconstructs element migration during listvenitization, including the possible role of magnesium in native gold precipitation. Gold mineralization is shown to be structurally controlled by contacts with altered granite-porphyry dikes, quartz veins, crushing zones, and sulfide assemblages, especially associations involving galena. The study interprets ore formation as a multistage hydrothermal-metasomatic process and compares the occurrence with other gold-bearing listvenite systems, supporting its exploration significance.
Full Text
Gold-Bearing Listvenites—A New Type of Mineralization in the Northern Kuznetsk Alatau
A. I. Goncharenko (TTU)
Gold-bearing listvenites, established in the hyperbasites of the northern part of the Kuznetsk Alatau \[3\], represent a new and promising type of gold mineralization for this region. The zone of listvenites is confined to the eastern contact of the hyperbasite massif of Mount Severnaya–Zelenaya with amphibole schists and is saturated with thin quartz and quartz–feldspar veins accompanying dikes of granite-porphyries (Fig. 1). The internal structure of the zone is complicated by intense, locally developed crumpling and crushing of the rocks.
On the basis of the composition of the original rocks, two types of formations are distinguished in the indicated zone—ortho- and epilistvenites \[5\]. Ortholistvenites, as products of the metasomatic alteration of hyperbasites, are the most widespread rocks and make up the endocontact part of the massif. Immediately adjoining the ortholistvenites along the crumpling zone are epilistvenites, which arose as a result of the metasomatic transformation of the enclosing amphibole schists.
Among the ortholistvenites, the leading role belongs to talc-carbonate rocks, composing the outer zone of metasomatically altered hyperbasites. These formations gradually, through talc-carbonate-serpentine and carbonate-serpentine rocks, pass into unaltered serpentinites. The talc-carbonate rocks are colored light- or yellowish-gray, are coarsely schistose, sometimes strongly crumpled, and often outwardly resemble talc schists.
Under the microscope, a granolepidoblastic texture of the rocks is observed, characterized by a uniform arrangement of a fine-grained aggregate of magnesite (grain size 0.05–0.01 mm) in the fine-scaled main fabric of talc. Sometimes this texture is complicated by the presence of larger (up to 1–2 mm) grains and irregular veinlet-like accumulations of breunnerite. The ratio of carbonate to talc varies over wide limits, which in a number of cases leads to the formation, on the one hand, of substantially talcose rocks, and on the other—of almost monomineralic carbonate rocks. Among the impurities in the listvenites, the presence of serpentine, fuchsite, and chlorite is noted. Ore minerals are represented by relict grains of chromian spinel, as well as by magnetite and pyrite.
As a result of subsequent metasomatic alteration of the hyperbasites, quartz–talc–carbonate rocks arise. In this case the texture of the talc-carbonate rocks becomes massive, and the structure—
Fig. 1. Geological section along the listvenite zone in the area of Mount Zelenaya.
1 — amphibole schists; 2 — serpentinites; 3 — orthogneisses: a) talc–carbonate rocks, b) quartz–carbonate rocks; 4 — epilistvenites; 5 — granite-porphyry dikes; 6 — beresite-like quartz–mica rocks; 7 — quartz veins; 8 — quartz–feldspar veins; 9 — tectonic fractures; 10 — geological boundaries: a) sharp, b) gradual; 11 — zones of crushing; 12 — direction of rock schistosity; 13 — gold-ore zones.
fine-grained. In their composition, in addition to talc and carbonate, the appearance of quartz is noted; it forms scattered grains of irregular shape and aggregate accumulations in the talc–carbonate mass. Sometimes quartz is segregated in the form of thin veinlets. Its content ranges from 1–2 to 10–15%.
The microstructure of the quartz–talc–carbonate listvenites is granolepidoblastic. The diverse variations of this structure that are observed are related to the features of the mutual arrangement and quantitative ratio of the mineral components.
With deeper alteration of ultrabasic rocks, quartz–carbonate listvenites arise; these are of practical interest, since in a number of cases they are gold-bearing. Listvenites of this type occur among talc–carbonate rocks as steeply dipping, slab-like bodies from 1 to 8 m thick and differ from other metasomatic formations in a number of structural and textural features. Externally, quartz–carbonate listvenites are very dense, fine-grained rocks with a characteristic network of fine-veinlet quartz. Quartz veinlets develop independently or are apophyses of quartz veins confined to a system of parallel, steeply dipping fractures. The mineralogical composition of the listvenites is very simple and is determined by a combination of two minerals—quartz and carbonate. The composition of the latter varies from weakly ferruginous magnesite to breunnerite, to which dolomite is not infrequently added. The microstructure of the rocks is grano- and heterogranoblastic.
Among the ortholistvenites, a special type of potassic listvenites is distinguished; these differ by the presence in their composition of muscovite and phlogopite. The listvenites are enriched in micaceous minerals at the contact with dikes of granite-porphyries and quartz–feldspar veins, where in a number of cases monomineralic phlogopite rocks are recorded.
The process of metasomatic alteration of amphibole schists is, in its character, close to propylitization, which is expressed in the formation of epidote, quartz, clinozoisite, albite, diopside, actinolite, chlorite, and calcite. The minerals mentioned develop as rare veinlets up to 3–5 cm wide among exceptionally fresh schists. The texture of the veinlets often proves to be thinly banded because of the zonal distribution of the rock-forming components.
Propylitized amphibole schists at the contact with ortholistvenites are replaced by epilistvenites (Fig. 1), among which quartz–albite–mica–carbonate varieties are the most characteristic. Externally, these are gray massive rocks penetrated by thin quartz veinlets, near which are located fine-flaked accumulations of emerald-green fuchsite. The listvenites contain an increased amount of pyrite (up to 3–5% and more).
Under the microscope, a microgranolepidoblastic structure is observed in the rocks, the main mass of which is composed of carbonate grains, irregular in shape, up to 0.1 mm in size, and small flakes of muscovite. Against the background of the mica–carbonate aggregate, areas consisting of quartz and sericitized albite are clearly distinguished; the latter not infrequently forms relatively large (up to 0.2 mm) individuals.
In tectonically active zones, in aposchistose listvenites, the appearance of biotite is noted; its flakes are distributed more or less uniformly in the quartz–albite–carbonate mass and, by their elongation, coincide with the direction of schistosity of the rocks.
Among other varieties of the formations described, it should be noted that, observed in direct proximity to amphibole schists—
Table 1
Chemical composition of the original rocks, ortho- and epilistvenites
| Oxides | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ortolistvenites | Ortolistvenites | Ortolistvenites | Ortolistvenites | Ortolistvenites | Ortolistvenites | Epilistvenites | Epilistvenites | Epilistvenites | Epilistvenites | Epilistvenites | Epilistvenites | |||
| SiO₂ | 40.18 | 33.04 | 32.43 | 20.88 | 43.32 | 30.49 | 28.17 | 51.78 | 43.00 | 39.06 | 40.45 | 32.90 | 43.48 | 33.98 |
| TiO₂ | 0.03 | 0.13 | 0.05 | 0.13 | 0.12 | 0.04 | 0.03 | 0.42 | 0.66 | 0.80 | 0.62 | 0.54 | 0.94 | 0.91 |
| Al₂O₃ | 0.76 | 0.26 | 0.49 | 0.23 | 2.33 | 1.03 | 1.16 | 14.14 | 12.98 | 16.16 | 15.69 | 11.19 | 12.92 | 14.18 |
| Fe₂O₃ | 3.56 | 2.39 | 2.11 | 1.78 | 1.27 | 0.91 | 0.11 | 3.11 | 3.78 | 3.10 | 1.99 | 4.97 | 3.37 | 2.96 |
| Cr₂O₃ | 0.52 | 0.40 | 0.30 | 0.44 | 0.19 | 0.25 | 0.24 | — | 0.26 | 0.12 | 0.02 | 0.08 | 0.20 | 0.10 |
| FeO | 3.59 | 2.51 | 3.89 | 4.67 | 3.58 | 4.64 | 5.36 | 11.29 | 8.62 | 10.42 | 7.94 | 8.08 | 8.44 | 12.21 |
| NiO | 0.28 | 0.27 | 0.16 | 0.16 | 0.14 | 0.11 | 0.16 | — | 0.14 | — | — | 0.03 | 0.01 | — |
| MnO | 0.15 | 0.25 | 0.20 | 0.34 | 0.12 | 0.13 | 0.17 | 0.05 | 0.19 | 0.25 | 0.13 | 0.34 | 0.32 | 0.32 |
| MgO | 42.93 | 33.64 | 30.30 | 32.33 | 22.31 | 30.09 | 29.76 | 2.28 | 11.04 | 9.60 | 5.23 | 7.42 | 6.55 | 6.44 |
| CaO | — | — | 0.69 | — | 1.14 | 0.22 | 0.28 | 9.94 | 10.45 | 7.22 | 5.69 | 9.04 | 7.01 | 10.79 |
| Na₂O | — | — | 0.07 | — | 0.10 | 0.05 | 0.05 | 3.55 | 1.18 | 1.06 | 2.89 | 0.65 | 1.27 | 0.78 |
| K₂O | — | — | 0.15 | — | 0.78 | 0.08 | — | 0.60 | 1.62 | 1.36 | 3.00 | 3.47 | 3.47 | 2.83 |
| H₂O | 8.20 | 4.06 | 4.51 | 8.10 | 2.84 | 3.50 | 5.08 | 2.07 | 1.80 | 2.40 | 2.10 | 1.91 | 2.28 | 1.44 |
| CO₂ | — | 23.10 | 24.08 | 30.06 | 20.79 | 28.00 | 29.97 | 0.14 | 5.20 | 9.64 | 13.22 | 16.57 | 9.78 | 10.90 |
| P₂O₅ | 0.03 | 0.05 | — | 0.06 | — | 0.01 | 0.04 | 0.66 | 0.09 | 0.05 | 0.02 | 0.09 | 0.00 | 0.14 |
| S | 0.06 | 0.03 | 0.09 | 0.03 | 0.08 | 0.10 | 0.01 | — | 0.04 | 0.03 | 0.64 | 2.37 | 0.14 | 1.13 |
| Σ | 100.31 | 100.11 | 99.53 | 99.21 | 99.08 | 99.65 | 100.60 | 99.49 | 101.05 | 101.33 | 99.64 | 100.13 | 100.24 | 99.11 |
| Specific gravity | 2.71 | 2.81 | 2.49 | 2.86 | 2.69 | 2.74 | 2.76 | 2.94 | 2.86 | 2.88 | 2.74 | 2.80 | 2.91 | 2.81 |
Note. 1—serpentinite; 2—talc-carbonate rock; 3—quartz-mica-carbonate rock; 4—quartz-talc-carbonate rock; 5—mica-quartz-carbonate rock; 6—talc-quartz-carbonate rock; 7—quartz-carbonate rock; 8—amphibole schist; 9—carbonate-albite-actinolite rock; 10—albite-mica-actinolite-carbonate rock; 11, 12—quartz-mica-albite-carbonate rocks; 13—biotite-albite-quartz-carbonate rock; 14—chlorite-carbonate-albite-mica rock.
Formulas of rocks calculated according to the atomic-volume system [4]
Ortolistvenites
\[ \mathrm{N_1:}\ \mathrm{Si}_{109.1}\ \mathrm{Al}_{2.2}\ \mathrm{Fe}^{+3}_{7.3}\ \mathrm{Cr}_{1.1}\ \mathrm{Fe}^{+2}_{8.1}\ \mathrm{Ni}_{0.6}\ \mathrm{Mn}_{0.3}\ \mathrm{Mg}_{175.7}\ \mathrm{Ca}_{0.0}\ \mathrm{Na}_{0.0}\ \mathrm{K}_{0.0}\ [\mathrm{O}_{418.7}(\mathrm{OH})_{74.2}]_{492.9} \]
\[ \mathrm{N_2:}\ \mathrm{Si}_{95.5}\ \mathrm{Al}_{3.1}\ \mathrm{Fe}^{+3}_{[[unclear]]}\ \mathrm{Cr}_{0.6}\ \mathrm{Fe}^{+2}_{11.6}\ \mathrm{Ni}_{0.4}\ \mathrm{Mn}_{0.2}\ \mathrm{Mg}_{146.1}\ \mathrm{Ca}_{0.5}\ \mathrm{Na}_{0.5}\ \mathrm{K}_{0.0}\ [\mathrm{O}_{299.6}(\mathrm{OH})_{93.0}(\mathrm{CO}_2)_{57.4}]_{450.0} \]
\[ \mathrm{N_3:}\ \mathrm{Si}_{80.9}\ \mathrm{Al}_{1.4}\ \mathrm{Fe}^{+3}_{3.9}\ \mathrm{Cr}_{0.5}\ \mathrm{Fe}^{+2}_{8.1}\ \mathrm{Ni}_{0.3}\ \mathrm{Mn}_{0.2}\ \mathrm{Mg}_{112.7}\ \mathrm{Ca}_{1.8}\ \mathrm{Na}_{0.0}\ \mathrm{K}_{0.4}\ [\mathrm{O}_{254.8}(\mathrm{OH})_{37.5}(\mathrm{CO}_2)_{164.2}]_{495.5} \]
\[ \mathrm{N_4:}\ \mathrm{Si}_{60.0}\ \mathrm{Al}_{0.7}\ \mathrm{Fe}^{+3}_{3.8}\ \mathrm{Cr}_{1.1}\ \mathrm{Fe}^{+2}_{0.9}\ \mathrm{Ni}_{0.3}\ \mathrm{Mn}_{0.7}\ \mathrm{Mg}_{138.0}\ \mathrm{Ca}_{0.0}\ \mathrm{Na}_{0.0}\ \mathrm{K}_{0.0}\ [\mathrm{O}_{215.5}(\mathrm{OH})_{155.0}(\mathrm{CO}_2)_{114.4}]_{484.9} \]
\[ \mathrm{N_5:}\ \mathrm{Si}_{128.1}\ \mathrm{Al}_{4.6}\ \mathrm{Fe}^{+3}_{1.6}\ \mathrm{Cr}_{0.5}\ \mathrm{Fe}^{+2}_{6.5}\ \mathrm{Ni}_{0.1}\ \mathrm{Mn}_{0.1}\ \mathrm{Mg}_{96.4}\ \mathrm{Ca}_{1.8}\ \mathrm{Na}_{0.6}\ \mathrm{K}_{5.1}\ [\mathrm{O}_{248.4}(\mathrm{OH})_{55.7}(\mathrm{CO}_2)_{59.6}]_{363.7} \]
\[ \mathrm{N_6:}\ \mathrm{Si}_{83.7}\ \mathrm{Al}_{3.2}\ \mathrm{Fe}^{+3}_{1.8}\ \mathrm{Cr}_{0.5}\ \mathrm{Fe}^{+2}_{10.3}\ \mathrm{Ni}_{0.2}\ \mathrm{Mn}_{0.2}\ \mathrm{Mg}_{128.2}\ \mathrm{Ca}_{0.6}\ \mathrm{Na}_{0.3}\ \mathrm{K}_{0.2}\ [\mathrm{O}_{352.4}(\mathrm{OH})_{64.1}(\mathrm{CO}_2)_{105.0}]_{522.5} \]
\[ \mathrm{N_7:}\ \mathrm{Si}_{78.0}\ \mathrm{Al}_{3.7}\ \mathrm{Fe}^{+3}_{[[unclear]]}\ \mathrm{Cr}_{0.5}\ \mathrm{Fe}^{+2}_{12.4}\ \mathrm{Ni}_{0.3}\ \mathrm{Mn}_{0.3}\ \mathrm{Mg}_{122.7}\ \mathrm{Ca}_{0.8}\ \mathrm{Na}_{0.3}\ \mathrm{K}_{0.0}\ [\mathrm{O}_{345.3}(\mathrm{OH})_{93.7}(\mathrm{CO}_2)_{113.2}]_{572.2} \]
Epilistvenites
\[ \mathrm{N_8:}\ \mathrm{Si}_{152.6}\ \mathrm{Ti}_{0.9}\ \mathrm{Al}_{49.0}\ \mathrm{Fe}^{+3}_{6.8}\ \mathrm{Fe}^{+2}_{27.8}\ \mathrm{Mn}_{0.1}\ \mathrm{Mg}_{10.0}\ \mathrm{Ca}_{31.3}\ \mathrm{Na}_{20.2}\ \mathrm{K}_{2.2}\ [\mathrm{O}_{451.0}(\mathrm{OH})_{10.6}(\mathrm{CO}_2)_{0.5}]_{492.0} \]
\[ \mathrm{N_9:}\ \mathrm{Si}_{123.2}\ \mathrm{Ti}_{1.4}\ \mathrm{Al}_{43.6}\ \mathrm{Fe}^{+3}_{8.1}\ \mathrm{Fe}^{+2}_{[[unclear]]}\ \mathrm{Mn}_{0.4}\ \mathrm{Mg}_{47.0}\ \mathrm{Ca}_{32.0}\ \mathrm{Na}_{7.5}\ \mathrm{K}_{5.8}\ [\mathrm{O}_{415.0}(\mathrm{OH})_{34.4}(\mathrm{CO}_2)_{20.3}]_{491.8} \]
\[ \mathrm{N_{10}:}\ \mathrm{Si}_{86.6}\ \mathrm{Ti}_{1.7}\ \mathrm{Al}_{58.0}\ \mathrm{Fe}^{+3}_{6.7}\ \mathrm{Fe}^{+2}_{25.1}\ \mathrm{Mn}_{0.5}\ \mathrm{Mg}_{41.3}\ \mathrm{Ca}_{22.4}\ \mathrm{Na}_{5.6}\ \mathrm{K}_{5.0}\ [\mathrm{O}_{382.9}(\mathrm{OH})_{46.2}(\mathrm{CO}_2)_{37.9}]_{467.0} \]
\[ \mathrm{N_{11}:}\ \mathrm{Si}_{111.0}\ \mathrm{Ti}_{1.2}\ \mathrm{Al}_{50.7}\ \mathrm{Fe}^{+3}_{4.1}\ \mathrm{Fe}^{+2}_{18.7}\ \mathrm{Mn}_{0.2}\ \mathrm{Mg}_{21.3}\ \mathrm{Ca}_{16.7}\ \mathrm{Na}_{15.3}\ \mathrm{K}_{10.5}\ [\mathrm{O}_{409.1}(\mathrm{OH})_{38.4}(\mathrm{CO}_2)_{49.5}]_{497.0} \]
\[ \mathrm{N_{12}:}\ \mathrm{Si}_{90.0}\ \mathrm{Ti}_{1.1}\ \mathrm{Al}_{37.0}\ \mathrm{Fe}^{+3}_{10.4}\ \mathrm{Fe}^{+2}_{18.4}\ \mathrm{Mn}_{0.7}\ \mathrm{Mg}_{31.0}\ \mathrm{Ca}_{27.0}\ \mathrm{Na}_{3.5}\ \mathrm{K}_{12.4}\ [\mathrm{O}_{295.5}(\mathrm{OH})_{35.5}(\mathrm{CO}_2)_{63.4}]_{494.2} \]
\[ \mathrm{N_{13}:}\ \mathrm{Si}_{126.8}\ \mathrm{Ti}_{2.0}\ \mathrm{Al}_{44.3}\ \mathrm{Fe}^{+3}_{7.4}\ \mathrm{Fe}^{+2}_{20.5}\ \mathrm{Mn}_{0.7}\ \mathrm{Mg}_{28.4}\ \mathrm{Ca}_{21.8}\ \mathrm{Na}_{7.1}\ \mathrm{K}_{12.9}\ [\mathrm{O}_{433.8}(\mathrm{OH})_{44.3}(\mathrm{CO}_2)_{38.9}]_{517.0} \]
\[ \mathrm{N_{14}:}\ \mathrm{Si}_{95.7}\ \mathrm{Ti}_{1.9}\ \mathrm{Al}_{47.0}\ \mathrm{Fe}^{+3}_{6.2}\ \mathrm{Fe}^{+2}_{28.7}\ \mathrm{Mn}_{0.7}\ \mathrm{Mg}_{27.0}\ \mathrm{Ca}_{32.5}\ \mathrm{Na}_{4.3}\ \mathrm{K}_{10.1}\ [\mathrm{O}_{395.4}(\mathrm{OH})_{26.0}(\mathrm{CO}_2)_{41.9}]_{463.2} \]
Note. In calculating formulas 4–7, talc-carbonate rocks were taken as the original rocks (analysis 2),
...albite–actinolite–carbonate and albite–actinolite rocks.
As follows from the characterization given above, ortho- and epilistvenites differ from one another in a number of geological and petrographic features, which is reflected in the specifics of their chemistry (Table 1).
Study of the metasomatic zoning that arises during listvenitization of hyperbasites and their enclosing rocks made it possible to identify certain regularities in the change of their composition. As calculations of the absolute number of atoms of elements in a standard geological volume of rocks \((N^+)\), carried out by the atomic-volume system [4], have shown, the formation of ortholistvenites was accompanied by introduction, by solutions enriched in potassium and carbon dioxide, of Ca, Al, Fe\(^{+2}\), and partly Si, which were removed from amphibole schists (Table 1). The formation of epilistvenites proceeded with the introduction of magnesium, which migrated from the hyperbasite substrate. As established by material-balance calculation, magnesium underwent migration at all stages of the listvenitization process, up to ore formation. Possessing strong polarizing properties, magnesium undoubtedly contributed to the destruction of complex compounds of gold and to its precipitation in native form. Some researchers [7] arrived at similar conclusions in studying gold-bearing skarns.
Gold mineralization in listvenites is localized within three closely spaced ore zones (Fig. 1). The first zone is spatially confined to the contact between epi- and ortholistvenites, where a dike of beresitized granite porphyries is recorded. In the hanging wall of the dike the listvenites are intensely crushed and contain dense disseminations of pyrite, together with which arsenopyrite, galena, sphalerite, molybdenite, chalcopyrite, and native gold occur. The listvenites of the footwall of the granite-porphyry dike, where the sulfide mineralization is represented by pyrite, galena, and sphalerite, are distinguished by an elevated gold content. A quartz vein occurring here also proves to be gold-bearing.
The principal element of the morphology of the second gold-ore zone is a system of fractures confined to the eastern contact of the granite-porphyry dike. In the central part of the zone, in the listvenites, there is a barren quartz vein of variable thickness, cut by a later vein of gold-bearing quartz. This gives rise to brecciation zones 10–30 cm wide, characterized by a rather high gold content. The listvenites enclosing the veins contain many thin branching quartz veinlets, by which the selvage bands are especially densely saturated. Ore minerals—galena, sphalerite, and pyrite—form nest-like accumulations in the veins and listvenites, in contrast to the quartz breccias, where they are dispersed in the cementing mass.
The listvenites of the third gold-ore zone are cut by a series of parallel, discontinuous quartz veins 0.1–0.5 m thick.
The structural position of the gold mineralization in the listvenites, as is evident from the data presented, is determined by its close connection with dikes of metasomatically altered granite porphyries, accompanied by bunches of quartz veins of variable thickness. The distribution of gold has a clearly expressed “clustered” character. It occurs both in association with sulfides and independently of them. The connection of gold with galena is especially close, to which we have already drawn attention [3]. Comparison of the results of fire-assay and spectral analyses of 373 samples showed that, as the gold content in the listvenites increases, there is an increase in the frequency of occurrence in them not only of lead, but also of silver and bismuth, which enter isomorphously into
the galena lattice. At the same time, lead and silver are present in all samples containing more than 20 g/t gold.
Geological-petrographic and mineralogical study, with the involvement of mineragraphic observations [3], makes it possible to regard ore formation in listvenites as a complex, multi-stage process that proceeded under conditions of repeatedly renewed tectonic movements. Four stages of the hydrothermal-metasomatic process are preliminarily distinguished. The first stage is characterized by the formation of veins of dark-gray massive quartz. In the second stage, veins of milky-white medium-crystalline quartz were introduced; abundant pyritization and graphitization of the listvenites are associated with them. The third, ore-forming stage proper of mineral formation appears to be the most complex and protracted in time, consisting of at least three stages of mineralization separated by intra-ore tectonic movements: pyrite–arsenopyrite, gold–polymetallic, and gold–scheelite. The final stage is barren and is expressed in the formation of quartz–magnesite veinlets cutting the listvenites.
Gold-bearing listvenites in association with ultrabasic rocks are known in a number of regions of the Soviet Union [1, 2, 9] and abroad [6]. Industrial concentrations of gold are not infrequently associated with formations of this type; as in the listvenites studied by us, this gold is characterized by an extremely uneven distribution. It is sufficient to mention that “in serpentinite formed during the hydrothermal alteration of peridotite” in the Blovett district [6], the gold content ranges from 5 g to 16 kg per ton.
The gold ore formation described in listvenites, in terms of the conditions of its geological-structural position and the nature of the manifestation of wall-rock alterations, compares well with a deposit currently being exploited in Armenia [8], which is yet another proof of the prospects of a new genetic type of mineralization in the Kuznetsk Alatau.
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