Metamorphism (greenschist facia down) of terrigenous rocks in the northern part of the Kularsky gold-bearing district, Yakutia: mineral ratios with cleavage

In the Kularsky gold-bearing area, where 170 tons of gold were extracted from placers, primary gold deposits have not been well studied; therefore, their development requires detailed geological analysis including the study of rock metamorphism. A large Ulakhan-Sis anticline composed of Permian carbonaceous-terrigenous rocks is found on the northwestern flank of the Kular-Nersky folded belt of the Verkhoyano-Kolyma orogenic region. In this article we describe the material composition of carbonaceous-terrigenous rocks prevalent in the northern part of the Kularsky district. The degree of their postdiagenetic transformations varies from metagenesis in Triassic rocks to muscovite-chlorite and biotite subfacies of the greenschist facia of metamorphism in Permian rocks of the Ulakhan-Sis anticline. As the transition from metagenesis to muscovite-chlorite and biotite subfacies of metamorphism the degree of recrystallization of rocks, the grain sizes of the recrystallization of clastic quartz and the width of newly formed muscovite flakes are increasing, monazite, ilmenite, biotite flakes appear in rocks. These changes occur before the completion of formation in the rocks of the S₁ slate cleavage.

After the formation of the latter, mainly before the appearance of a later crenulation cleavage S₂, crystallization of pyrite occurs in the rocks. Porphyroblasts of biotite and magnesiosiderite appear during the formation of a crenulation cleavage S₂. The appearance of biotite during the formation of the S₁ and S₂ cleavages may correspond to the theories about the two-stage metamorphism of the rocks of the area. Thus, further metamorphism studies in this region are required.

1. Goryachev N.A. Geology of mesozoic gold-quartz vein belts in Northeast Asia. Magadan: North-Eastern Scientific Research Institute of the Far Eastern Branch of the Russian Academy of Sciences; 1998. 210 p. (In Russ.)

2. Fridovsky V.Yu. Kular metallogenic zone: metamorphogenic Au and quartz deposits. In: Parfenov. L.M. and Kuz’min M.I. (eds.) Tectonics, geodynamics and metallogeny of the Sakha Republic (Yakutia). Moscow: MAIK “Nauka/Interperiodika”; 2001, pp. 350–353. (In Russ.)

3. Lazareva E.V., Zhmodik S.M., Prokopyev A.V., et al. Nodular monazite from placers of the Kular Ridge (Arctic Siberia, Russia): composition, age estimates. Russian Geology and Geophysics. 2018;(10):1658–1679. (In Russ.). http://dx.doi.org/10.15372/GiG20181010

4. Parfenov L.M., Oksman V.S., Prokoiev A.V. Terrane collage of the Verkhoyansk-Kolyma orogenic region. In: Parfenov. L.M. and Kuz’min M.I. (eds.) Tectonics, geodynamics and metallogeny of the Sakha Republic (Yakutia). Moscow: MAIK “Nauka/Interperiodika”; 2001, pp. 199– 255. (In Russ.)

5. Sustavov O.A. Deformations of vein quartz during the formation of gold mineralization in black shale strata (Kularsky region, Eastern Yakutia). Russian Geology and Geophysics. 1995;(4):81–87. (In Russ.)

6. Vernon R.H. A practical guide to rock microstructure. Cambridge University Press; 2018. 431 p. https://doi.org/10.1017/9781108654609

7. Passchier C.W., Trouw R.A.J. Microtectonics. Berlin; Heidelberg: Springer- Verlag; 2005. 366 p.

8. Kirmasov A.B. Fundamentals of structural analysis. Moscow: Nauchnyi mir; 2011. 368 p. (In Russ.)

9. Sustavov O.A., Shagalov E.S. Magnesiosiderite and monazite in carbonaceous shales of the northern part of the Kular region, Yakutia. Ural’skaya mineralogicheskaya shkola [Urals Mineralogical School]. 2021;(27): 117–119. (In Russ.)

10. Bushmakin A.F. Inherited structure of pyrite crystals from rocks with carbonaceous matter. In: Grigor’ev D.P., et al (eds.) Problems of minerals ontogeny. Leningrad: Nauka; 1985, pp. 73–82.

11. Sustavov O.A. Cleavage microstructures and stretching indicators in black-shale rocks of the northern part of the Ulakhan-Sis antiform (Kularsky district, Yakutia). Arctic and Subarctic Natural Resources. 2021;26(3): 31–42. (In Russ.). https://doi.org/10.31242/2618-9712-2021-26-3-31-42

12. Perkova R.I., Sustavov O.A., Bushmakin A.F. Isotopic composition of sulfur sulfides of gold-bearing quartz veins and pyritized zones in black shales of one of the regions of Yakutia. In: 8th All-Union symposium on stable isotopes in geochemistry, Moscow, November 11–14, 1980. Moscow; 1980, pp. 337–338. (In Russ.)

13. Sustavov O.A. Dynamic recrystallization of quartz in veins in sandstones of the metagenesis zone (Kularsky district, Yakutia). Proceedings of higher educational establishments. Geology and Exploration. 2018;(6):33–40. (In Russ.). https://doi.org/10.32454/0016-7762-2018-6-33-40

14. Sustavov O.A. Quartz veins at the southern part of Adycha-Elgi anticlinorium and zone of Adycha-Taryn fault, Yakutia. Lithosphere (Russia). 2018;18(1):111–126. (In Russ.). https://doi.org/10.24930/1681-9004-2018-18-1-111-126

15. Yapaskurt O.V. The aspects of the postsedimental lithogenesis theory. Lithosphere (Russia). 2005;(3):3–30. (In Russ.)

16. Turnbull I. M., Mortimer N., Craw D. Textural zones in the Haast Schist—a reappraisal. New Zealand Journal of Geology and Geophysics. 2001;44(1):171–183.

17. Nakamura Y., Akai J. Microstructural evolution of carbonaceous material during graphitization in the Gyojayama contact aureole: HRTEM, XRD and Raman spectroscopic study. Journal of Mineralogical and Petrological Sciences. 2013; 106(3):131─143. https://doi.org/10.2465/jmps.120625

18. Čopjaková R., Novák M., Franců E. Formation of authigenic monazite-(Ce) to monazite-(Nd) from Upper Carboniferous graywackes of the Drahany Upland: Roles of the chemical composition of host rock and burial temperature. Lithos.2011;127:373–385. https://doi.org/10.1016/j.lithos.2011.08.001

19. Rusinov V.L., Rusinova O.V., Kryazhev S.G., et al. Wall-rock metasomatism of carbonaceous terrigenous rocks in the Lena gold district. Geology of Ore Deposits. 2008;50(1):1–40. (In Russ.). https://doi.org/10.1134/s1075701508010017

20. Portnov A.M., Zhadnova T.P. Ilmenite-bearing metamorphic shales of the Patom Highlands. Izvestiya Akademii Nauk SSSR Seriya Geologicheskaya [Bulletin of the Academy of Sciences of the USSR. Geological Series]. 1969;(2):124–127. (In Russ.)

21. Kidder S., Avouac J.-P., Chan Y.-C. Constraints from rocks in the Taiwan orogen on crustal stress levels and rheology, Journal of Geophysical Research. 2012; 117. https://doi.org/10.1029/2012JB009303

22. Korikovsky S.P. Facies of metapelite metamorphism. Moscow: Nauka; 1979. 263 p. (In Russ.)

23. Konstantinov M.M., Konstantinovsky F.F., Natalenko M.V. Typification of gold mining areas in the terrigenous shale belts of Russia. Regional Geology and Metallogeny. 2013;(54):75–88. (In Russ.)

24. Prior D.J. Syntectonic porphyroblast growth in phyllites: textures and рrocesses. Journal of Metamorphic Geology. 1987;(5):27–39.

25. Yudovskaya M.A., Distler V.V., Mokhov A.V., et al. Relationship between metamorphism and ore formation at the Sukhoi Log gold deposit hosted in black slates from the data of U-Th-Pb isotopic SHRIMP-dating of accessory minerals. Geology of Ore Deposits. 2011;539(1): 27–57. https://doi.org/10.1134/S1075701511010077

26. Large R.R., Maslennikov V.V., Robert F., et al. Multistage Sedimentary and Metamorphic Origin of Pyrite and Gold in the Giant Sukhoi Log Deposit, Lena Gold Province, Russia. Economic Geology. 2007; 102(7):1233–1267. http://dx.doi.org/10.2113/gsecongeo.102.7.1233

27. Bell T.H., Sanislav I.V., Sapkota J. The control of deformation partitioning and strain localization on porphyroblast behaviour in rocks and experiments. Geosciences Journal. 2018;22:65–77. https://doi.org/10.1007/s12303-017-0030-8