The Shape and Size Gorikhinsky Granite Massif (Mongolia)
The Gorikhinsky granite massif is located in the marginal part of the Khentei highlands of the Mongol-Trans-Baikal folded system of Central Mongolia. Crystal deposits and numerous ore occurrences of other minerals are associated with the granites of the massif. These data served as the basis for setting up flat-stage gravimetric work to determine the features of its geological structure in order to clarify the metallogenic specialization. The work was performed using scintrex autograv CG-5 gravimeters using the standard method. The heights of the observation points were determined by Trimble 5700 GPS devices. The mean-square accuracy of calculating gravitational anomalies and the density of the observation network meet the technical requirements for 1:100000 scale gravimetric surveys. Based on the results of a medium-scale areal gravimetric survey performed on the territory of the Gorikhinsky granite massif, a map of the anomalia gravity in the buge reduction was obtained. Based on the interpretation of this data, a volume model of the array is built. Its power reaches up to 3.5 km, the area of projection on the earth's surface is twice the area of the outputs. Information about the shape and size of the massif can be used in the conclusion about the prospects of its metallogenic specialization, the features of which were established earlier by geological, geophysical and geochemical methods, as well as in the development of ideas about the formation and mechanism of penetration of acidic intrusions into the upper parts of the earth's crust. A distinctive feature of the geological and geophysical sections of the Gorikhinsky massif is that the deep faults, along with the lateral control of the massif, also limit its vertical limits. Thus, the fault structures qualitatively confirm the reliability of the performed geological and geophysical interpretation. It should be noted that the interpretation of gravitational anomalies in most cases gives a fairly rough idea of the deep structure of granite plutons, even with a known lack of density and taking into account the position of their exits to the earth's surface.
Turutanov Evgeny Khrisanfovich, Doctor of Sciences (Geology and Mineralogy), Chief Researcher, Head, Laboratory Complex Geophysics, Institute of the Earth's Crust SB RAS, 128, Lermontov st., Irkutsk, 664033, Russian Federation, e-mail: email@example.com
Buyantogtokh Bazarin, Researcher, Center for Astronomy and Geophysics MAS, PO-788, Ulaanbaatar-210613, Mongolia, Postgraduate, Institute of the Earth's Crust SB RAS, 128, Lermontov st., Irkutsk, 664033, Russian Federation, e-mail: firstname.lastname@example.org
Tengis Badma, Researcher, Center for Astronomy and Geophysics MAS, PO-788, Ulaanbaatar-210613, Mongolia, Postgraduate, Institute of the Earth's Crust SB RAS, 128, Lermontov st., Irkutsk, 664033, Russian Federation
Turutanov E.Kh., Buyantogtokh B., Tengis B. The Shape and Size Gorikhinsky Granite Massif (Mongolia). The Bulletin of Irkutsk State University. Series Earth Sciences, 2020, vol. 31, pp. 85-101. https://doi.org/10.26516/2073-3402.2020.31.85 (in Russian)
Marinov N.A., Zonenshayn L.P., Blagonravov V.A. (eds.). Geologiya Mongolskoi Narodnoi Respubliki. Vol. 1. Stratigrafiya [Geology of the Mongolian People's Republic. Vol. 1. Stratigraphy]. Moscow, Nedra Publ., 1973, 582 p. (in Russian)
Hasin R.A., Borzakovskii Yu.A., Zonenshayn L.P. (eds.) Geologiya Mongol'skoi Narodnoi Respubliki. Vol. 2. Magmatizm, metamorfizm, tek-tonika. [Geology of the Mongolian People's Republic. Vol. 2. Magmatizm, metamorfizm, tektonika]. Moscow, Nedra Publ., 1973, 752p. (in Russian)
Kosuhin O.N., Bakumenko I.T., Chupin V.P. Magmaticheskiy etap formirovaniya granitnyih pegmatitov [Magmatic stage of formation granite pegmatites]. Novosibirsk, Nauka Publ., 1984, 136 p. (in Russian)
Imayev V.S., Semenov R.M. (eds.). Seysmichnost i rayonirovaniye seysmicheskoy opasnosti territorii Mongolii. Irkutsk, Institut zemnoy kory SB RAS Publ., 2009, 420 p.
Tauson L.V. Geohimicheskie tipi i potentsialnaya rudonosnost granitoidov [Geochemical types and potential ore content of granitoids]. Moscow, Nauka, 1977, 280 p. (in Russian)
Turutanov E.Kh. Morfologiya mezozoiskikh granitnykh plutonov Mongolii po gravimetricheskim dannym [Morphology of Mesozoic granite plutons of Mongolia by gravimetric data]. Irkutsk, IRGTU Publ., 2012, 223 p. (in Russian)
Bankwitz P. Magmentektonloche Aspekte der Intrusion des Erzgebirgeplutons. Geolog. und Geophys. Veroff, 1975, vol. 3, no. 36, p. 48.
Biehler S.A., Bonini W.E. Geopysical Interpretation of the Boulder Batholith, Montana. Trans. Amer. Geophys. Union, 1966, 47, no. 1, p. 192.
Brown M. Granite: From genesis to emplacement. Geological Society of America Bulletin, 2013, no. 7-8. pp. 1079-1113. https://doi.org/10.1130/B30877.1
Campbell D. S., Jonson D. J. Bouguer gravity stady of Enumclaw Pinnacle peak. Nortwest Sci., Washington, 1982, no. 2, pp. 90–100.
Castro A. The off-crust origin of granite batholiths. Geoscience Frontiers, 2014, vol. 5. pp. 63-75.
Dzhurik V.I., Dudarmaa T. (eds.). Complex geophysical and seismological investigations in Mongolia. Ulaanbaatar, Irkutsk, 2004, 315 p.
Eggler D.H. Gravity survey of the Livermore-Tie Siding area, Colorado-Wyoming. Mountain Geol., 1967, vol. 4, no. 3, pp. 109-114.
Fairhead J.D., Walker P. The geological interpretation of gravity and magnetic surveys over the exposed southern margin of the Galway Granite, Ireland. Geol. J., 1977, vol. 12, no. 1, pp. 17-24.
Healey D. L., Miller C. H. Gravity survey of the Gold Meadows stock, Nevada Test Site, Nye County, Nevada. Geol. Sury. Profess. Paper, 1963, vol. 475B, pp. 64-66.
Whitelaw J.L., Mickus K., Whitelaw M.J., Nave J. High-resolution gravity study of the Gray Fossil Site. East Tennessee State University. Department of Geosciences, Springfield, Missouri. USA. Geophysics, 2008, vol. 73, no. 2, pp. В25-В32.
Howard D. Geophysical studies of the Minarets Wilderness and adjacent areas, Madera and Mono counties, California. Geol. Surv. Bull., 1982, 1516 A, pp. 49-72.
Lind G. Gravity measurements over the Bohua Granite in Sweden. Geol. fohrn. Stockholm forhanadl, 1967, vol. 88, no. 4, pp. 542-548.
Smith N., Cassidy J., Locke C.A., Mauk J.L., Christie A.B.J. Nye role of regional scale faults in controlling a trapdoor caldera, Coromandel Peninsula. New Zealand Volcanol and Geotherm. Res., 2006, vol. 149, no. 3-4, pp. 312-328.
Oclsner C. Die gravimetrischen Spezialvermessungen des Gebietes Geger. Freiberger Forschungs, Ehrenfriedersdorf, 1963, no. 167, pp. 85-93.
Pitсher W.S. The anatomу of batholiths. Journ. Geol. Soc., London, 1978, vol. 135, no. 2, pp. 157-182.
Ramodass G., Ramaprasada Rao I.B., Himabindu D. Crustal configuration of the Dharwar craton, India, based on joint modeling of regional gravity and magnetic data. J. Asian Earth Sci., 2006, 26, no. 5, pp. 437-448.
Rowston D.L. Gravity survey of manganese deposits in the Mt. Sydney-Woodie Woodie area, Pilbara Goldfield. Geol. Surv. West. Austral. Annual. Rept., 1965, vol. 1, pp. 49-51.
Stephanson O., Johnson K. Granite diapirism in the Rum Jungle area, Northern Australia. Precambrian Res., 1976, vol. 3, no. 2, pp. 159-185.
Webring M. Semi-automatic Marquardt inversion of gravity and magnetic profiles. U. S. Geological Survey Open-File Report OF 85-122.