Инд. авторы:	Safonova I.Y., Simonov V.A., Kurganskaya E.V., Obut O.T., Romer R.L., Seltmann R.
Заглавие:	Late Paleozoic oceanic basalts hosted by the Char suture-shear zone, East Kazakhstan: Geological position, geochemistry, petrogenesis and tectonic setting
Библ. ссылка:	Safonova I.Y., Simonov V.A., Kurganskaya E.V., Obut O.T., Romer R.L., Seltmann R. Late Paleozoic oceanic basalts hosted by the Char suture-shear zone, East Kazakhstan: Geological position, geochemistry, petrogenesis and tectonic setting // Journal of Asian Earth Sciences. - 2012. - Vol.49. - P.20-39. - ISSN 1367-9120. - EISSN 1878-5786.
Внешние системы:	DOI: 10.1016/j.jseaes.2011.11.015; SCOPUS: 2-s2.0-84859077562;
Реферат:	eng: The paper presents the first data on geochemistry (major and trace elements, isotopes) of the Late Devonian-Early Carboniferous basalts of the Char suture-shear zone in East Kazakhstan, and includes detailed analysis of their geological relations and petrogenesis (fractional crystallization/melting modeling). Three groups of oceanic basalts coexist in the Char zone. Group 1 basalts are associated with oceanic siliceous sediments and have medium TiO 2, relatively flat REE patterns (La/Sm n=0.7, Gd/Yb n=1.3), Zr/Nb av.=42 and εNd av.=6.3. They formed at high degrees of melting of a depleted mantle source and were erupted in a mid-oceanic ridge setting. Group 2 basalts are associated with both chert and carbonate and have higher TiO 2, Hf, Y, Zr and P 2O 5 than the rocks of Group 1. They are similarly characterized by low Nb (Nb/La pm<1) and flat REE patterns (La/Sm n=0.6, Gd/Yb n=1.1), εNd av.=8.3, and Zr/Nb=44. Group 2 basalts originated under lower degrees of melting than Group 1 basalts from a depleted mantle source, and possibly formed in a subducting oceanic plateau setting. Group 3 basalts are enriched in incompatible elements, i.e. have high LREE (La/Sm n=1.8), differentiated HREE (Gd/Yb n=2.3), Nb positive anomalies in the multi-element diagrams (Nb/Th pm=1.5, Nb/La pm=1.1), low Zr/Nb ratio (∼9) and lower εNd av.=4.6. They formed at lower degrees of melting, compared to Groups 1 and 2, from a heterogeneous mantle source in the spinel (Gd/Yb n<2) and garnet (Gd/Yb n>2) stability fields. They possibly represent fragments of oceanic islands/seamounts formed in relation to mantle plume. © 2011 Elsevier Ltd.
Ключевые слова:	water-rock interaction; trace element; tectonic setting; suture zone; stratigraphy; shear zone; petrogenesis; Paleozoic; orogenic belt; mid-ocean ridge basalt; mantle source; mantle plume; igneous geochemistry; Kazakhstan; chert; basalt; accretion; Water-rock interaction; OIB; Oceanic plateau; Oceanic Plate Stratigraphy; MORB; Major and trace elements; Isotopes; Central Asian Orogenic Belt; Accretion; garnet;
Издано:	2012
Физ. характеристика:	с.20-39