3-18-3

APATITE SHELLS OF THE DEVONIAN FORAMINIFERS (SAFYANOVSKY COPPER-SULPHIDE DEPOSIT, MIDDLE URAL)

E. I. Soroka, L. V. Leonova, A. L. Anphimov

УДК 563.12 (470.5) https://doi.org/10.21440/2307-2091-2018-3-34-39

 

E. I. Soroka et al. / News of the Ural State Mining University 3 (2018) 34-39

Relevance of the work is due to the possibility of a detailed study of Devonian foraminifers with apatite shells and the reconstruction of specific conditions for their formation. Foraminifer shells are morphologically similar to Parathurammina aff. tamarae L. Petrova, 1981, the Eifelian-the Givetian, which were found in thin sections of samples of carboniferous and chiselly aleuropelites of the ore-bearing strata of the Safyanovsky copper-sulphide deposit (Middle Urals) for the first time.
Purpose of work. Detailed study of the shells of Devonian foraminifers similar to Parathurammina aff. tamarae L. Petrova, 1981, as well as reconstruction of sedimentation conditions for carboniferous and chiselly rocks of the ore-bearing strata of the Safyanovsky copper-sulphide deposit.
Research methodology. Shells were studied in thin sections of carboniferous and chiselly aleuropelite samples. The detailed study of morphology and composition of the shells was carried out using a scanning electron microscope JSM-6390LV (JEOL) with an energy-dispersive spectrometer Inca Energy 450, an electron microscope Tescan and an electron probe microanalyzer Cameca SX100.
Results. Size and morphology of the shells were determined; it was also found that the walls of the shells of the studied foraminifers were represented by fluorapatite. It was assumed that initially they were calcareous, and subsequently were replaced by apatite and quartz. However, more detailed studies did not reveal traces of substitution of carbonate rock for apatite.
Conclusions. Compared with Parathurammina aff. tamarae L. Petrova, 1981, shells have a reduced size and a smaller number of fauces, which can be explained by unfavorable habitats in a shallow sea basin, where carbonate sedimentation was suppressed by a significant influx of volcanic material. The presence of sulfide minerals in nucleus of shells may indicate to the specific habitat (pH of the environment, salinity of supra-bottom water) of foraminifers. Findings of fossils of green, siphon algae together with studied foraminifers indicate that formation of the original substrate took place in
near-surface layers (up to 200 m) of the photic zone of seas.

Keywords: Middle Urals, Safyanovsky copper-sulphide deposit, fossils, Devonian foraminifers, fluorapatite.

 

REFERENCES

1. Chuvashov B. I, Anfimov A. L., Soroka E. I., Yaroslavtseva N. S. 2011. Novyye dannyye o vozraste rudovmeshchayushchey tolshchi Saf’yanovskogo mestorozhdeniya (Sredniy Ural) na osnove foraminifer [New data on the age of the ore-bearing sequence of the Safyanovsky deposit (Middle Urals) on the basis of foraminifers]. Doklady Akademii nauk [Doklady Earth sciences], vol. 439, no 5. pp. 648–650.
2. Anfimov A. L., Soroka E. I., Yaroslavtseva N. S., Glavatskikh S. P. 2011, Genezis uglerodisto-kremnistykh prosloyev v rudovmeshchayushchey vulkanogenno-osadochnoy tolshche Saf’yanovskogo mednokolchedannogo mestorozhdeniya (Sredniy Ural) [Genesis of carbon-siliceous interlayers in the ore-bearing igneous-sedimentary stratum of the Safianovsky copper-pyrite deposit (Middle Urals)]. Vulkanizm i geodinamika: V Vserossiyskiy simpozium po vulkanologii i paleovulkanologii [Volcanism and geodynamics: V All-Russian academic conference on volcanology and paleovolcanology]. Ekaterinburg, pp. 474–476.
3. Yaroslavtseva N. S., Maslennikov V. V., Safina N. P. et al. 2012, Uglerodsoderzhashchiye alevropelity Saf’yanovskogo medno-tsinkovokolchedannogo mestorozhdeniya (Sredniy Ural) [Carboniferous aleuropelites of the Safyanovsky copper-zinc-pyrite deposit (Middle Urals)]. Litosfera [Litosfera], no 2, pp. 106–123.
4. Soroka E., Leonova L., Pritchin M., Maidl T. 2018, Fossil algae as indicators of the depositional environment. Proceedings of Kazan Golovkinsky- 2017. Bologna, pp. 321–325.
5. Petrova L. G. 1981, Foraminifery srednego devona vostochnogo sklona Urala. Paleozoy Zapadno-Sibirskoy nizmennosti i yeye gornogo obramleniya [Foraminifera of the Middle Devonian of the eastern slope of the Urals. Paleozoic of the West Siberian lowland and its mountain range]. Novosibirsk, pp. 81–101.
6. Chuvashov B. I., Anfimov A. L., Soroka E. I., Yaroslavtseva N. S. 2012, Devonskiye foraminifery s nekarbonatnoy rakovinoy v rudovmeshchayushchey tolshche Saf’yanovskogo mestorozhdeniya (Sredniy Ural) [Devon foraminifers with a non-carbonate shell in the ore-bearing strata of the Safyanovsky deposit (Middle Urals)]. Litosfera [Litosfera], no. 5, pp. 114–125.
7. Berberian T. K. 1983, Framboid-piritnyye agregaty v rudakh kolchedannykh mestorozhdeniy i ikh geneticheskoye i poiskovoye znacheniye [Framboid-pyrite aggregates in ores of pyrite deposits and their genetic and search value]: extended abstract of PhD thesis. Novocherkassk, 165 p.
8. Kasioptas A., Geisler Th., Perdikouri Ch., Trepmann C., Gussone N., Putnis A. 2011, Polycrystalline apatite synthesized by hydrothermal replacement of calcium carbonates. Geochemica et Cosmochemica Acta, vol. 75, pp. 3486–3500.
9. Deer W. A., Howie R. A., Zussman J. 1966, Rock-forming minerals. Moscow, vol. 5, 405 p.
10. Potapov S. S., Parshina N. V., Potapov D. S. 2005, Neskol’ko primerov morfologii, stroyeniya i mineralogii urolitov zhiteley Chelyabinskoy oblasti [Some examples of morphology, structure and mineralogy of urolites of Chelyabinsk region residents]. Vestnik Ural’skogo otdeleniya Rossiyskogo mineralogicheskogo obshchestva [Bulletin of the Ural Branch of the Russian Mineralogical Society], no. 4, pp. 96–99.
11. Golovanova O. A. 2010, Termodinamicheskoye modelirovaniye patogennogo mineraloobrazovaniya [Thermodynamic modeling of pathogenic mineral formation]. Mineraly: stroyeniye, svoystva, metody issledovaniya [Minerals: structure, properties, research methods]. Proceedings from II All-Russian youth scientific conference (March 23–26). Miass, pp. 139–141.
12. Katvala E. C., Henderson C. M. 2012, Chemical element distributions within conodont elements and their functional implications. Paleobiology, vol. 38, pp. 447–458. DOI 10.1666/11038.1.
13. Zhuravlev A. V., Shevchuk S. S. 2017, Strontium distribution in Upper Devonian conodont elements: a palaeobiological proxy. Rivista Italiana di Paleontologia e Stratigrafia, vol. 123 (2), pp. 203–210.
14. Zadorozhny V. M. 1987, Foraminifery i biostratigrafiya devona Zapadno-Sibirskoy plity i yeye skladchatogo obramleniya [Foraminifers and biostratigraphy of the Devonian of the West Siberian Plate and its folded frame]. Trudy instituta geologii i geofiziki SO AN SSSR [Proceedings of the Institute of Geology and Geophysics of the Siberian Branch of the Academy of Sciences of the USSR], issue 680, 126 p.
15. Lutova Z. V. 1981, Stratigrafiya i foraminifery kelloveya severa Sredney Sibiri [Stratigraphy and foraminifers Callovian north of Central Siberia]. Moscow, 134 p.

Лицензия Creative Commons
All articles posted on the site are available under the Creative Commons Attribution 4.0 Global License.