Fossil coprolites of Meso-Cenozoic animals as a source of mineralogical-geochemical, paleontological and paleoecological information

Research subject. In this article, we present the results of comparative mineralogical and geochemical studies of organic remains and coprolites from the Lower Triassic and Paleogene continental deposits of the Northern Urals and East Kazakhstan.

Methods. The studies were conducted using a wide range of analytical methods, including optical microscopy; chemical analysis; determination of C_org content; thermal and powder X-ray diffraction analysis; spectroscopy; scanning electron microscopy; X-ray fluorescence analysis; isotopic analysis gas pyrochromatography; inductively coupled plasma mass spectrometry.

Results. A significant concentration of fish bones, teeth and scales, as well as coprolites of labyrinthodonts were identified in the Lower Triassic and Paleogene continental-marine terrigenous and carbonate-terrigenous sedimentary rocks of the Northern Urals and East Kazakhstan. In terms of mineral composition, the fossils and coprolites are found to be almost completely composed of B-type carbonate apatite. The phase-heterogeneous impurities in the coprolites are represented by calcite, siderite, barite, polycomponent carbonates of the MnCO₃–FeCO₃–MgCO₃–CaCO₃ system and pyrite. It should be noted that pyrite demonstrates octahedral habitus, which is rather rare for this mineral. The ratio of the essential and xenobiotic elemental concentrations differs for the Lower Triassic and Paleogene coprolites, reaching 0.17 and 0.35 on average, respectively. For the first time, information has been given on the content of lithogenic gases in coprolites and the isotopic composition of the impurity carbonaceous material. According to this data, Lower Triassic labyrinthodonts could feed on plants, as well as herbivorous and carnivorous fish.

Conclusion. The findings of coprolites in the Northern Urals and East Kazakhstan in a wide Meso-Cenozoic chronological range and in highly different geological settings indicate the probability of a much wider development of coprogenic-phosphate sedimentary rocks in nature than it has been previously considered. Under a high concentration of coprolites, these rocks can serve as a new and extremely valuable type of phosphorite raw materials, the utilization of which would not require any preliminary treatment.

1. Bliskovskii V.Z. (1979) Mineralogical nature of calcium phosphate phosphorites. Veshchestvennyi sostav fosfori-tov [Material composition of phosphorites]. Novosibirsk: Nauka Publ., 16-36. (In Russian)

2. Bliskovskii V.Z., Fridman N.G., Kuz’mina T.S. (1975) Thermographic study of the phosphate substance of phosphorites. Veshchestvennyi sostav fosforitovykh rud. Trudy GIGKhS [Material composition of phosphorite ores. Proceedings of GIGKhS], 30, 105-141. (In Russian)

3. Borneman-Starynkevich I.D., Belov N.V. (1953) About carbonate-apatites. DokladyAkad. NauksSsR, 90(1), 89-92. (In Russian)

4. Bradley W.H. (1946) Coprolites from formation of Wyoming: their composition and microorganisms. Amer. J. Sci., 244(3-4), 215-239.

5. Chalyshev V.I. (1961) The discovery of Triassic fish and stegocephalus in the Northern Urals. Doklady Akad. Nauk SSSR, 136(4), 904-906. (In Russian)

6. Chalyshev V.I. (1962) Marine Triassic in the Northern Urals. Doklady Akad. Nauk SSSR, 144(6), 1340-1343. (In Russian)

7. Chalyshev V.I. (1964) Phosphoritic deposits of the Lower Triassic in the Pechora Cis-Urals. Litol. Polezn. Iskop., 4, 124-126. (In Russian)

8. Chalyshev V.I. (1965) About the perspectives of phospho-rite-bearingness of Paleozoic and Mesozoic deposits of the Northern Cis-Urals. Geologiya i poleznye iskopaemye severo-vostoka evropeiskoi chasti SSSR i Severa urala. Trudy IV geol. konf Komi ASSR [Geology and minerals of the northeast of the European part of the USSR and the North of the Urals. Proceedings of the IV geol. confer. Komi ASSR]. Syktyvkar, 216-229. (In Russian)

9. Edwards P.D., Yatkova D. (1974) Coprolites of the White River (Oligocene) carnivorous mammals: origin, paleoecology and sedimentology significance. Wyoming uni-vers. Contribut. Geol., 13(2), 63-73.

10. Gilinskaya L.G. (1979) Electron paramagnetic resonance in calcium phosphate studies. Issledovanie fosfatov kal’tsiya fizicheskimi metodami [The studies of calcium phosphates by physical methods]. Novosibirsk: Nauka Publ., 39-48. (In Russian)

11. Knubovets R.G. (1976) The results of the phosphorite investigation by infrared spectroscopy method. Litologi-ya fosforitonosnykh otlozhenii [Lithology of phosphorite deposits]. Moscow, Nauka Publ., 124-136. (In Russian)

12. Knubovets R.G. (1979) Some crystallochemical features of the real structure of calcium phosphates. Issledovaniya fosfatov kal’tsiya fizicheskimi metodami [The studies of calcium phosphates by physical methods]. Novosibirsk, Nauka Publ., 22-29. (In Russian)

13. Krivokoneva G.K. (1964) About the carbonate fluorapatite from the Argaynnakhkhai intrusive deposit. Rentgeno-grafiya mineral ’nogo syr ’ya [Radiography of mineral raw materials]. Moscow, Nedra Publ., 64-74. (In Russian)

14. Kulikova G.V., Borisov B.A. (1986) About the phosphori-tized coprolites from the continental Paleogene deposits of the Zaysanskaya Depression (East Kazakhstan). Doklady Akad. Nauk SSSR, 289(2), 443-449. (In Russian)

15. Kulikova G.V., Lipatova E.A., Rozinova E.L., Sosed-ko T.A., Furmakova L.N. (1991) The results and methodological aspects of the francolite diagnosis in fossils and coprolites. Zapiski VMO, 3, 116-133. (In Russian)

16. Kuz’mina T.S. (1979) Thermal analysis of calcium phosphates. Issledovanie fosfatov kal’tsiya fizicheskimi metodami [The studies of calcium phosphates by physical methods]. Novosibirsk, Nauka Publ., 63-67. (In Russian)

17. Lapo A.V. (1979) Sledy bylykh diosfer.The traces of the former biospheres. Mocow, Znanie Publ., 58-59. (In Russian)

18. Maidl’ T.V., Beznosov P.A., Smoleva I.V., Silaev V.I. (2016) The results of mineralogical and geochemical studies of ichthyofossils and unusual micromineralization from Devonian carbonate deposits on Southern Timan. Sovre-mennye problemy teoreticheskoi, eksperimental’noi i prikladnoi mineralogii (Yushkinskie chteniya - 2016) [The modern problems of theoretical, experimental and applied mineralogy (Yushkin Readings - 2016)]. Syktyvkar, Geoprint Publ., 152-153. (In Russian)

19. Maslennikov B. M., Kavitskaya F. A. (1956) About the phosphate substance of phosphorites. Doklady Akad. Nauk SSSR, 109(5), 190-192. (In Russian)

20. McConnell D. (1938) A Structural investigation of the isomorphism of the apatites group. Amer. Mineral., 11, 699-707.

21. McConnell D. (1977) Apatite, its chemistry, mineralogy, utilization and geologic and biologic occurrences. Wien; N.Y., 111 p.

22. Nakamoto K. (1991) IR and Raman spectra of inorganic coordination compounds. Moscow, Mir Publ., 536 p. (In Russian)

23. Naugol’nykh S.V. (2011) Paleoecological palimpsest. Priro-da, 2, 69-75. (In Russian)

24. Novikov M.V. (1994) Biostratigraphy of the continental Tri-assic of the Timan-Severouralsk region according to the tetrapod fauna. Moscow, Nauka Publ., 139 p. (In Russian)

25. Rosseeva E.V., Frank-Kamenetskaya O.V., Golovanova O.A., Shvarts U., Knip R. (2009) Isomorphic substitutions in the structure of carbonate-containing fluorapatites obtained by biomimetic synthesis. Vestn. st.petersb. st/ univ. ser. 7, 3, 35-48. (In Russian)

26. Rosseeva E.V., Zimon P., Shvarts U., Buder Ya., Frank-Kamenetskaya O.V., Knip R. (2009) Apatite-gelatin nanocomplexes - the analogs of biological solid tissues. 1. Synthesis and characterization of composites. Isomorphic substitutions in the structure of carbonate-bearing apatite-(CaF). Zapiski RMo, 4, 53-71. (In Russian)

27. Silaev V.I. (1996) Mineralogy of phosphate-bearing weathering crusts. St.-Petersburg, Nauka Publ., 136 p.(In Russian)

28. Silaev V.I., Ponomarev D.V., Simakova Yu.S., Shani-na S.N., Smoleva S.V., Tropnikov E.M., Khazov A.F. (2016) Contemporary studies of fossil bone detritus: paleontology, mineralogy, geochemistry. Vestn. Instituta geologii Komi NTs uro Ran, 5, 19-31. (In Russian)

29. Silaev V.I., Yanulova L.A., Terent’ev A.V. (1997) Thermal transformations of hypergenic manganites from the manganese hat of the Parnok ferromanganese manifestation. syktyvkarskii mineralogicheskii sbornik No. 26. Syktyvkar, Geoprint Publ., 131-137. (In Russian)

30. Silaev V.I., Zaboev A.F., Ilovaiskii V I., Khoroshilova L.A. (1977) Phase transformations of some sulfides during heating. Eksperiment v mineralogii i modelirovanie mineraloobrazuyushchikh protsessov [Experiment in mineralogy and modeling of mineral-forming processes]. Syktyvkar, IG Komi Filial Akad. Nauk SSSR 88-96. (In Russian)

31. Vasil’eva Z.V. (1968) Mineralogical features and chemical composition of apatite. Apatity [Apatites]. Moscow, Nauka Publ., 31-56. (In Russian)

32. Vyalov A.S. (1982) Late Pleistocene coprolites from the North Caucasus. paleontologicheskii sbornik [Paleontological collection of works], 19, 57-60. (In Russian)

33. Young R.A., Elliott I.C. (1966) Atomic-scale bases for several properties of apatites. Arch. oral. Biol, 11, 699-707.

34. Yudovich Ya.E., Ketris K.P. (2000) Fundamentals of litho-chemistry. St.-Petersburg, Nauka Publ., 479 p. (In Russian)

35. Yushkin N.P., Silaev V.I., Zharkov V.A., Filippov V.N., Lyutoev V.P., Simakova Yu.S. (2013) Mesozoic coprolites: mineralogical-geochemical properties and attitude towards the phosphate-bearing prognosis. problemy mineralogii, petrografii i metallogenii: Materialy nauchnykh chtenii pamyati P.N. Chirvinskogo - 2013 [The issues of mineralogy, petrography and metallogeny: the materials of scientific readings in memory of P.N. Chirvinsky -2013]. Perm, Perm St. Univ. Publ., 26-52. (In Russian)