PETROCHEMICHAL MODELS OF THE TOMTOR FIELD CARBONATITES (EASTERN SIBERIA)
Keywords:
carbonatites, alkali rocks, ultrabasic rocks, system approach, mathe-matical statistics, genetic hypotheses, phosphorus deposits, Tomtor field, Eastern Siberia.Abstract
The chemical composition of the Tomtor field rocks has been investigated using the core of 193 boreholes located in the line crossing the rock mass from southeast to northwest. As many as 2 100 chemical analyses of rocks have been studied on the basis of system approach using the mathematical statistics methods to distinguish homogene-ous rock groups composing the field. The database of chemical compositions was pre-liminarily divided into 43 groups by the cluster analysis method. The mean composi-tions of the groups within the SiO2–(Na2O+K2O) diagram were concentrated within the boundaries of six discrete series. The first two series correspond to the compositions of alkali-syenite and alkali-gabbro, respectively, the third series – to melilite-like rocks, and the series from the fourth up to the sixth are presented by polygenetic carbonatites which we called polycarbonatites. All series could be characterized by extremely high variations of the compositions increasing from the third series towards the first and sixth series. The third series was considered as the parental one for the entire rock mass, it occurred as a result of selective melting of alkali-basalts under the conditions of СО2 saturation. The endogenous carbon dioxide was present at all rock formation stages. The phosphorus behaviour has been specially studied. The petrochemical criteria for checking the genetic hypotheses of mineable phosphorus agglomerates formation were formulated. The presence of gravitational (residual) and metasomatic phosphorus ag-glomerates was defined in the rocks under investigation. It is shown that the rock series have been distinguished reliably; similar petrochemi-cal series take place in other apatite deposits, so they can also be used for geological mapping.
References
Altschuller Z. S. Distribution of phosphorus in carbonatites / Z. S. Altschuller // Phosphorus in the Environment. - Moscow : Mir, 1977. – P. 47–56. (in Russian)
Apatite Rocks of Seligdar / V. B. Vasilenko, L. G. Kuznetsova, L. D. Kholodova [et al.]. - Novosibirsk : Nauka, 1982. - 215 p. (in Russian)
Baturin G. N. Phosphate Rocks on Bottom of Oceans / G. N. Baturin. - Moscow : Nauka, 1978. - 231 p. (in Russian)
Belousov A. F. Volcanic Formations / A. F. Belousov, A. P. Krivenko, Z. G. Polyakova. - Novosibirsk : Nauka, 1982. - 281 p. (in Russian)
Chetverikov S. D. Handbook on Petrochemical Recalculations of Rocks Analyses and Determination of Chemical Types of Rocks / S. D. Chetverikov. - Moscow : Gosnauchtekhizdat, 1956. - 245 p. (in Russian)
Classification of Kimberlites and Internal Structure of Kimberlite Pipes. - Moscow : Nauka, 1981. - 136 p. (in Russian)
Cramer H. Mathematical Methods of Statistics / H. Cramer. - Moscow : Mir, 1975. - 648 p. (in Russian)
Diday E. The dynamic clusters method in nonhierarchical clustering / E. Diday // Intern. J. Соmр. Inform. Sci. - 1973. - N 2. - P. 61-88.
Crossref · Google Scholar
Epshtein E. M. Geology of unique Tomtor deposit of rare metals (North of the Siberian Platform) / Е. М. Epshtein, N. А. Danilchenko, S. A. Postnikov // Geologiya Rudnyh Mestorozhdeniy (Rus.). - 1994. - Vol. 36, N 2. - P. 83-110.
Geological Vocabulary. Vol. 1. - Moscow : Nedra, 1978. - 486 p. (in Russian)
Kimberlites and Carbonatites. Collection of Studies on Petrochemistry / V. B. Vasilenko, L. G. Kuznetsova, V. A. Minin [et al.]. - Novosibirsk : Parallel, 2013. - 745 p. (in Russian)
Krumbein W. Models of Geological Processes / W. Krumbein, M. Kaufman, R. McCammon. - Moscow : Mir, 1973. - 149 p. (in Russian)
Kuznetsov Yu. A. Main Types of Magmatic Formations / Yu. A. Kuznetsov. - Moscow : Nedra, 1964. - 387 p. (in Russian)
McKelvey V. E. Occurrence and distribution of phosphorus in the lithosphere / V. E. McKelvey // Phosphorus in the Environment. - Moscow : Mir, 1977. - P. 24-46. (in Russian)
Method for estimating potential platinum content of stratified gabbroids based on petrochemical model / V. B. Vasilenko, A. P. Krivenko, L. G. Kuznetsova, L. D. Kholodova // Geologiya i Geofizika (Rus,). - 1995.- Vol. 36, N 12. - P. 24-46. (in Russian)
Perchuk L. L. Chemical relationship of fluids and magma / L. L. Perchuk // Fluids in Magmatic Processes. - Moscow: Nauka, 1982. - P. 269-280. (in Russian)
Petrochemistry of СаО and Р2О5 in kimberlites and genesis problem of Seligdar apatite rocks (Aldan) / V. B. Vasilenko [et al.] // Petrochemistry, Genesis and Ore-Bearing of Siberian Magmatic Formations. - Novosibirsk : Nauka, 1985. - P. 171-178.
Petrochemistry of Subalkaline Carbonatite-Bearing Complexes of Siberia / V. B. Vasilenko, N. N. Zinchuk, L. G. Kuznetsova, V. P. Serenko. - Novosib : Nauka, 1994. - 231 p. (in Russian)
Razumova V. N. Ancient Weathering Crusts and Hydrothermal Process / V. N. Razumova. - Moscow : Nauka, 1977. - 156 p. (in Russian)
Standard quartz as a crite of Botuobinskaya pipe kimberlites / V. B. Vasilenko, A. V. Tolstov, V. A. Minin, L. G. Kuznetsova // Geologiya i Geofizika (Rus.). - 2008. - Vol. 49, N 12. - P. 1189-1204.
Tolstov A. V. Prospects for mining the Tomtor deposit of complex niobium-rareearth ores / A. V. Tolstov, N. P. Pokhilenko // EKO (Rus.) - 2 P. 17-27.
Zavaritsky A. N. Igneous Rocks / A. N. Zavaritsky. - Moscow : AN SSSR, 1955. - 479 p. (in Russian)
