On peculiarities of U and Th migration in the Dzhamanshur granodioritic intrusion and the Teshiktash extrusive dome the (South-Eastern Pamirs)

The North-East part of the Jamanshurinsk Lower Cretaceous intrusive is an apical part of granitoid massif. It is composed of granodiorites of the second (main) phase of the alichursk complex instilled into Triassic shales. The Teshiktash Lower Cretaceous extrusive dome is incorporated into the Aksuysky volcano-plutonic massif located in a large brakhisyncline of mountain limestone. The massif is composed largely of monconites, latites and their lavobreccias of the first (kyzylrabad) phase. Variation diagrams of isotope distribution across vertical sections have been constructed. In the Jamanshurinsk intrusive which is a closed physicochemical system the uranium and thorium concentration decreases in the upper direction from 3 to 1 g/ton and 2 to 1 g/ton, respectively. In Teshiktash dome which is a semiopen physicochemical system the content of both elements grows in the same direction from 1.5 to 2.5 g/ton. Accordingly, 3 zones of high concentration, moderate migration and intensive migration were identified in the vertical section. These zones in the Jamanshurinsk intrusive correspond to, respectively, deep, main and apical facies. In the Teshiktash dome the same zones correspond to apical, middle and deep facies, respectively