RELATIVE PLASTICITY OF ROCKS AS A CONTROLLING FACTOR IN ORE-DEPOSITION

Akba-i-Dzhurnon intrusion possesses a great many of the common primary fractures, planar and linear flow structures, schlieren-arch fabric features of many of the medium to coarse grained to porphyritic textured Precambrian plutons of the world. The following features are most important with regard to this pluton: 1) a sequential triple emplacement of granite-adamellite magma occurred, 2) the Main phase emplacement lowered magma level in magma chamber and resulted in subsidence of the core of Archannaydansk anticline under the dense sheeted-arch structure of the Tangisaysk thrust and the space created was occupied by magma; 3) subphase granites were injected along same fault systems as main phase pulses but were between the earlier injections and intervals between injections of different phases were short; 4), the pluton is post-tectonic; 5) porphyritic textures were developed in a combined pneumatolytic-magmatic crystallization stage; 6) trachytic structure formed during crystallization of orthoclase, and 7) conditions of alternating roof load and lateral pressure acting roughly perpendicular to the long axis of the pluton prevailed during its emplacement. — R. M. Hutchinson.