High-pressure melanocratic rocks of Anrakhai sialic massif (Southern Kazakhstan): the features of mineral, chemical compositions and metamorphism paths

• Main Authors: A. V. Pilitsyna, A. A. Tretyakov, K. E. Degtyarev, E. V. Kovalchuk
• Format: Article
• Language: Russian
• Published: Sergo Ordzhonikidze Russian State University for Geological Prospecting 2015-12-01
• Series: Известия высших учебных заведений: Геология и разведка
• Subjects: high-pressure metamoiphism; eclogites; garnet clinopiroxenites; southern kazakhstan
• Online Access: https://geology.mgri-rggru.ru/jour/article/view/86
• ISSN: 0016-7762; 2618-8708

In the structure of Anrakhai massif of Chu-Ili region (Southern Kazakhstan) metamoiphic formations of high-pressure conditions derivation (under eclogite facies field) were identified; the rocks are represented by eclogites and garnet clinopiroxenites. Investigation of mineral and chemical compositions of melanocratic high-pressure varieties as well as detailed petrographic and geological studies allowed characterizing P-T parameters of the metamorphic rocks formation (P 1,6-2,1 GPa; Г750-840°C), determining presumed protolith composition for them, that represented evidently the fragment of differentiated complex of mafic-ultramafic compositions, located within the continental crust prior metamorphism.