Petrography of the Bathonian Quartz Dioritic and Syenite-Dioritic Dike and Stock Intrusions of the Dizi Series

Author: Irakli Javakhishvili
Keywords: Dizi, Dizi Series, Diorite, Re, REE, Geochemistry
Annotation:

Dike and stock intrusives of the Dizi series (Southern slope of the Greater Caucasus, Upper Svaneti) connected with the Bathonian orogeny and known as Dizi intrusion (environs of the village of Dizi) are the object of study. K-Ar age of the intrusion is within the limits of 176-165 Ma. The intrusions are represented by 7 bodies (maximum thickness about one km). The following outcrops of intrusions are mapped: 1 – diorites and quartz-bearing syenite-diorites near the Svermildashi spring; 2 – quartz diorites and quartz-bearing syenite-diorites on the East of the Svermildashi; 3 – quartz-bearing syenite-diorites south of the Khvabishi cave; 4 – quartz-bearing syenite-diorites, diorites and gabbro in the environs of the village of Dizi; 5 – diorites and quartz diorites to the north of the village of Dizi; 6 – quartz-bearing syenite-diorites near the confluence of the rivers Enguri and Khumpreri (left tributary of the Enguri river); 7 – quartz-bearing syenite-diorites in the Lukhra river-gorge. Rock-forming minerals of diorites are represented by plagioclase, biotite, rarely hornblende; accessory minerals are represented by apatite, zircon, sphene and sagenite. Quartz diorites are of two types: biotite- and hornblende-bearing. Their rock-forming minerals are plagioclase, biotite, hornblende, quartz; accessory minerals – apatite and zircon. Quartz-bearing syenite-diorites are represented by K-feldspar, plagioclase, quartz, hornblende and biotite. Re and REE (Ti, P, Ba, Cl, Sr, Zr, Rb, Cs, Cu, V, Zn, Nd, Th, Pb, Y, Cr, Sn, Ga, Nb, Co, Ce, U, La, Ta, Ni, Hg, Sb, W, Hf, Tl, Bi, As, Mo, Se, Br) content in the intrusions of outcrops of the village of Dizi and the rivers Khumpreri and Lukhra first is analyzed by us. Pertochemical and geochemical data ((Na2O+K2O/Si2O; AFM; Al-(K+Na+2Ca/Fe+Mg+Ti; Rb-Sr/SiO2) established that the studied bodies are low and high aluminous sub-alkali rocks of calc-alkali series belonging to upper and lower crustal formations.

Lecture files:

დიზის სერიის ბათური ასაკის კვარციან-დიორიტული და სიენიტ-დიორიტული დაიკური და შტოკური ინტრუზივების პეტროგრაფია [ka]
Petrography of the Bathonian Quartz Dioritic and Syenite-Dioritic Dike and Stock Intrusions of the Dizi Series [en]