2026-10-15T21:46:55Z https://data.mendeley.com/oai

oai:data.mendeley.com/ynwykbwcrj.1 2020-03-31T14:16:06Z

Khromykh, Sergey Data for: Syncollisional Gabbro in the Irtysh Shear Zone, Eastern Kazakhstan: Compositions, Geochronology, and Geodynamic Implications Mendeley Data Petrographical, mineralogical, geochemical, and geochronological studies reveal three mineralogically and chemically different types of gabbro intrusions in the Irtysh shear zone in Eastern Kazakhstan: (1) gabbrodolerite and dolerite, (2) enriched biotite-bearing gabbro, and (3) layered peridotite-gabbro (largest intrusion). The rocks formed by fractional crystallization from two types of parent magmas, with their compositions (a) similar to tholeiitic subalkaline basalt (gabbro of types 1 and 2) and (b) intermediate between tholeiitic and calc-alkaline series being relatively depleted and more magnesian (type 3 gabbro). Geochemical and isotopic data indicate a sublithospheric subduction-related mantle source for the two types of primary magmas, which were produced, respectively, by low- and high-degree partial melting of depleted mantle material (spinel lherzolite). The obtained U-Pb and Ar-Ar ages of the gabbro samples (317-313 Ma) fall within the time of a collisional orogenic event. As predicted by geodynamic models, ascending mafic melts from a mantle wedge may intrude through windows in the sublithospheric mantle in the presence of slab discontinuity at the transform boundary of colliding plates along the Irtysh shear zone. Asian Geology Dataset doi:10.17632/ynwykbwcrj.1 oai:data.mendeley.com/ynwykbwcrj.1 Public Domain Dedication http://creativecommons.org/publicdomain/zero/1.0/ https://data.mendeley.com/datasets/ynwykbwcrj 2020-03-31T14:16:06Z