Open AccessLATERAL ZONALITY OF THE ANYUI SEGMENT OF THE CHUKCHI PLUTONIC BELT (WESTERN CHUKOTKA)
Author(s) -
В. Е. Стриха
Publication year - 2021
Publication title -
vestnik amurskogo gosudarstvennogo universiteta. seriâ "estestvennye i èkonomičeskie nauki"
Language(s) - English
Resource type - Journals
ISSN - 2073-0268
DOI - 10.22250/jasu.93.25
Subject(s) - leucogranite , quartz monzonite , geology , gabbro , geochemistry , pluton , batholith , cretaceous , plutonism , subduction , continental margin , igneous rock , paleontology , tectonics
Early Cretaceous granitoids of the Anyui segment of the Chukchi plutonic belt are represented by associations: gabbro-granite, monzodiorite-granite and granite-leucogranite. For the rocks of gabbro-granite and monzonite-granite associations with respect to the primitive mantle, enrichment of Cs, Rb, K was established, with depletion of Nb, Hf, Ti. Granitoids of the granite-leucogranite association are characterized by the most contrasting ratios of enriched and depleted elements, with deep lows of Ba, Nb, Sr, P, Ti against the background of high Cs, Rb, K, Th, U, as well as the absence of a minimum of Hf. Along with the presence of lateral zonality in the placement of granitoids in relation to the southwestern border of the Anyuy Terrain, these data suggest the subductive nature of the formation of gold-bearing gabbro-granite and monzonite-granite associations in the conditions of an active continental margin that arose in the southwestern part of the Chukchi Terrain in Early Cretaceous time due to subduction.