Petrographic Description of Some Coal Seams of the Tagarysh Deposit

A. A. Kurbatova

The Tagarysh deposit is located in the southwestern part of the Erunakovsky district of the Kuzbass. According to data from the Kuzbassuglegeologiya trust, the productive deposits of the Tagarysh structure belong to the Erunakovskaya suite. The deposit is characterized by a complex tectonic structure.

Since there are no published materials on the petrographic study of the coals of this deposit, below is given a description of the Tagarysh 3, 9, and 14 seams, which were sampled in 1951 jointly with E. M. Andreeva.

The pollen-spore characteristics of these seams were given by E. M. Andreeva [1].

Tagarysh 3 Seam

(Fig. 1,a)

Seam 3—the lowermost seam of the Tagarysh section—was sampled in adit No. 17. The seam thickness is 2.0 m; the description of the seam is given from the floor to the roof.

Layer 1. Lustrous, unevenly banded coal, consisting of alternating narrow bands of lustrous and semilustrous coal. The width of the bands is uneven; bands of lustrous coal predominate. In the semilustrous bands there occur small lenses of fusain (1 × 2 mm; 2 × 3 mm).

In thin section, banded coal is observed, consisting of alternating clarain and clarain-durain bands. The latter are enriched with particles of opaque-

Fig. 1. Petrographic sections of the Tagarysh 3 (a) and Tagarysh 14 (b) seams. Varieties of coal: 1—lustrous, almost homogeneous; 2—lustrous, unevenly banded; 3—lustrous, indistinctly banded; 4—semilustrous, banded. Rocks: 5—argillite; 6—siltstone.

substance. In the transparent brownish-red groundmass there is observed an insignificant quantity of microspores, slightly differing in color from the groundmass, and an almost complete absence of cuticle. Judging by the color shade of the microspores, the coal of this layer may be assigned to the grade of steam-fat (PZh) coals. Lenses of fuseno-xylene are confined to bands of clareno-durain composition. The thickness of the layer is 0.50 m.

The quantitative content of microcomponents in the coal of this variety is as follows: vitrinite-like substance — 80.0%, fusen — 4.0%, spore-like substance — 7.9%, xylene — 2.0%, mineral impurities — 5.0%, opaque substance — 1.0%.

This variety of bright, irregularly banded coal, in composition and in the quantitative ratios of its ingredients, is identical with that previously described by us [3] for seams 4 and 5 of the Chertinskoye deposit of Kuzbass.

Layer 2. Gray carbonaceous argillite with films of calcite. The thickness of the layer is 0.07 m.

Layer 3. Represented by the same variety of bright irregularly banded coal as in layer 1. The thickness of the layer is 0.52 m.

Layer 4. Semi-bright banded coal, in which bands of ash-rich durain coal predominate. Among the semi-bright groundmass of the coal there occur lenses of vitrinite, as well as fusen.

Microscopically this is coal of the clareno-durain type, containing an insignificant number of vitrinite lenses, a noticeable number of fuseno-xylene lenses, opaque groundmass, and mineral impurities. Vitrinite-like substance in the coal of this variety — 70.0%, fusen — 6.0%, spore-like substance — 6.2%, xylene — 1.6%, mineral impurities — 14%, opaque substance — 2.2%. The coal is of the type of the stratigraphically lower seams of the Chertinskoye deposit of Kuzbass. The thickness of the layer is 0.30 m.

Layer 5. Bright irregularly banded coal of the type of layers 1 and 3. The thickness of the layer is 0.61 m.

Tagarysh Seam 9

This seam lies 125 m stratigraphically above the Tagarysh 3 seam.

Several coal samples taken from the dumps of adit No. 18 were studied. The samples are represented mainly by bright coal; the coal is strongly calcitized and indistinctly banded.

In polished sections the coal of the seam is represented by excellent microsporous clarain: the transparent groundmass is saturated with a large quantity of bright-yellow microspores. Along with the latter, a large quantity of beautifully preserved sori is observed, which is a rather rare phenomenon among the coals of the Erunakovskaya suite. There is no cuticle in the polished sections, but fragments of microspores, also very well preserved, are encountered.

Judging by the color shade of the spores, the coal of this seam may be assigned to the gas-coal grade, which is not contradicted by the data of chemical analyses: volatiles in the seam, 37.03%.

The quantitative ratio of microcomponents in this coal is as follows: vitrinite-like substance — 71.0%; no fusen; spore-like substance — 26.0%; mineral impurities — 2.5%; no xylene.

Tagarysh Seam 14 (Fig. 1,б)

The seam, sampled in adit No. 23, is situated stratigraphically above the Tagarysh 9 seam by approximately 165 m. The thickness of the seam is 1.85 m.

Seam 1. Lustrous, indistinctly banded coal. In thin section there is an indistinct alternation of bands of clarain, vitrain, and, more rarely, clarain-durain. The transparent groundmass, reddish-brown in color, contains microspores slightly differing in color from the groundmass, isolated fragments of cuticle, and, more rarely, areas of opaque groundmass.

The vitrainized substance in coal of this variety is 86.0%, fusain 0.5%, spore-like substance 3.5%, mineral impurities 9.0%; there is no xylain; opaque substance 0.8%. Seam thickness 0.41 m.

Seam 2. Gray, dense, non-bedded aleurolite; seam thickness 0.10 m.

Seam 3. Lustrous, almost homogeneous coal. In thin section the reddish-brown groundmass predominates, containing microspores, cuticle, and rare fusain lenses as well as thread-like bands of durain-clarain. The quantitative ratios of the microcomponents in coal of this variety are as follows: vitrain-like substance 89.0%, fusain 0.5%, spore-like substance 5.5%, mineral impurities 5.0%; there is no xylain; opaque substance 0.3%. Seam thickness 0.13 m.

Seam 4. Thin-bedded argillite with interlayers of coaly material. Seam thickness 0.12 m.

Seam 5. Lustrous, almost homogeneous coal—the same as in seam 3. Seam thickness 0.12 m.

Seam 6. Lustrous, indistinctly banded coal of the same type as in seam 1. Seam thickness 0.77 m.

Seam 7. Lustrous, almost homogeneous coal, as in seams 3 and 4. Seam thickness 0.20 m. By the color shade of the cutinized elements, the coal of this seam may be assigned to the rank of steam-fat coals.

In conclusion, the following may be noted:

1. The studied seams of the Tagarysh deposit are composed of lustrous varieties.

Among the coals of the lustrous type, varieties of unevenly banded, indistinctly banded, and almost homogeneous coal have been distinguished.

The semi-lustrous type is represented by a variety of banded coal. Descriptions of the varieties and the quantitative ratio of microcomponents in them are given above in the descriptions of the seams.

1. The seams have a complex structure; the number of rock partings in them increases from bottom to top (seam 3—one parting, seam 16—four).

2. The seams are represented by coal of the durain-clarain and clarain type, with a small content of fusain material and an almost complete absence of cuticle.

3. The coals of this deposit are transparent in thin sections and, by the coloration of the formed elements, belong to the ranks of gas coal (seam 9) and steam-fat coal (seams 3 and 14).

4. Tagarysh seam 3, in petrographic structure, may be compared with seams 4 and 5 of the Chertinskoye deposit.

5. The overlying seams, in petrographic structure, are comparable with the upper seams of the Belovo-Babanakovo deposit, assigned by O. A. Betekhtina [2] to the second member of the Erunakovo suite.

Tagarysh seam 9 is distinguished by its distinctive composition: a large number of whole soruses, microspores, and macrospores (26.0%) take part in its composition.

References Cited

1. Andreeva E. M. Spore-and-pollen characteristics of the Balakhonka and Erunakovka series of Kuzbass. In: Atlas of the Guiding Forms of Fossil Fauna and Flora of the Permian Deposits of the Kuznetsk Basin. Gosgeoltekhizdat. 1956.

2. Betekhtina O. A. Stratigraphy of the Erunakovka Series of the Tagarysh Deposit of Kuzbass. Proceedings of Tomsk University, vol. 135. 1956.

3. Kurbatova A. A. Petrographic composition, nature, and facial variability of the coals of the Chertinskoye, Belovo-Babanakovskoye, Uskatskoye, and Karagailinskoye deposits of Kuzbass. Author’s abstract, Tomsk, 1954.

Tomsk Polytechnic Institute
named after S. M. Kirov