CONDITIONS ON THE FORMATION OF ECLOGITE CLASTS IN THE LOWER PERMIAN CONGLOMERATES, ATBASHY RIDGE
Keywords:
eclogite, P-T conditions, conglomerate, geochemistry, AtbashyRidge.Abstract
The petrological, mineralogical and geochemical characteristics of eclogite clasts in the Lower Permian conglomerates(the ArpaFormation) of the AtbashyRidge have been studied, and theirP-T conditions of formation have been obtained.Eclogite clasts consist mainly of garnet, omphacite, epidote, glaucophane, chlorite, white mica, quartz, and accessory minerals. Eclogites were formed from oceanic island arc and mid-ocean ridge (MORB) basalts, and experienced progressive metamorphism from epidote-glaucophane-schist facies to high pressure (T = 490– 590 °C; P = 15 kbar) eclogite facies, followed by retrograde stage in the greenschist facies. The obtained P-T conditions for the formation of eclogite clastsin the conglomerates are similar to the evolution of eclogites in the Choloktor complex.
References
(U)HP террейны Тянь-Шаня [Текст] / А.Б. Бакиров [и др.]. – Б.: Илим, 2017. – 232 с.
Бакиров А. Б. Геологическая карта Центральной части Атбашинского хребта в масштабе 1:50 000 [Карта] / А.Б. Бакиров, А.Р. Балбачан, Л.С. Котова // Институтгеологии АН Киргизской ССР. – 1984.
Сатыбаев M. M. Метаморфизм пелитовых сланцев атбашинского и чолокторского комплексов, Южный Тянь-Шань [Текст] / M.M. Сатыбаев [и др.] // Известия НАН КР. – 2019. – № 3. – С. 68-75.
Satybaev M. M. Petrology of metamorphic rocks from the Atbashy Complex, southern Tien-Shan, Kyrgyzstan [Текст] / M.M. Satybaev [и др.] // Geoscience Frontiers. – 2018. – № 9. – С. 1795-1807.
Бакиров А. Б. Породы метаморфических фаций сверхвысоких давлений в Тянь-Шане [Текст] / А.Б. Бакиров, М. Тагири, К.С. Сакиев // Геология и геофизика. – 1998. –Т. 39, – № 12, – С. 1722-1732.
Tagiri M. Mineral parageneses and metamorphic P-T path of ultrahigh-pressure eclogites from Kyrgyzstan, Tien-Shan [Текст] / M. Tagiri [и др.] // The Island Arc. – 1995. – № 4. – С. 280292.
Бакиров A. Б. Особенности строения и условия формирования эклогитоносных метаморфических формаций Тянь-Шаня [Текст] / А.Б. Бакиров // Кристаллическая кора в пространстве и времени – метаморфические и гидротермальные процессы. – М.: Наука, 1989. – С. 193-203.
Hegner E. Mineral ages and P-T conditions of Late Paleozoic high-pressure eclogite and provenance of mélange sediments from Atbashi in the south Tianshan orogen of Kyrgyzstan [Текст] // E. Hegner [и др.] // American Journal of Science. – 2010. – № 310. – С. 916-950.
Simonov V.A. Conditions of formation of the Atbashy Ridge eclogites (South Tien-Shan) [Текст] / V.A. Simonov [и др.] // Russian Geology and Geophysics. – 2008. – № 49. – С. 803-815.
Cox K. G. The Interpretation of Igneous Rocks [Текст] / K. G. Cox, J.D. Bell, R. J. Pankhurst // George Allen & Unwin, London. – 1979. – C. 450.
Jensen L. S. A New Cation Plot for Classifying Subalkaline Volcanic Rocks [Текст] / L. S. Jensen //Ontario Geological Survey Miscellaneous Paper. – 66. – 1976.
Meschede M. (1986). A Method of Discrimination between Different Types of Mid-Ocean Ridge Basalts and Continental Tholeiites with the Nb–Zr–Y Diagram [Текст] / M. Meschede // Chemical Geology. – 1986. – № 56. C – 207-218.
Boynton W. V. Geochemistry of the rare-earth elements: meteorite studies [Текст] / W.V. Boynton // Rare earth element geochemistry: Изд-во Elsevier, 1984. – С. 63-114.
Ellis E. An experimental study of the effect of Ca upon garnet-clinopyroxene Fe-Mg exchange equilibria [Текст]. / E. Ellis, D. Green // Contributions to Mineralogy and Petrology. – 1979. – № 71. – С. 13-22.
Powell R. Regression diagnostic and robust regression in geothermometer/geobarometer calibration: the garnet-clinopyroxene geothermometer revisited [Текст] / R. Powell // Journal of Metamorphic Geology. – 1985. – № 3. – С. 231-243.
Holland T. J. B. Experimental determination of the activities in disordered and short-range ordered jadeitic pyroxenes [Текст] / T.J.B. Holland // Contributions to Mineralogy and Petrology. – 1983. – № 82. – С. 214-220
