A new occurrence of sapphirine-spinel-corundum-bearing granulite from NE of Jagtiyal, Eastern Dharwar Craton, Andhra Pradesh

作者：Prakash D^*; Chandra Singh P; Hokada T

来源：Journal of the Geological Society of India, 2013, 82(1): 5-8.

DOI：10.1007/s12594-013-0115-6

We report a new occurrence of sapphirine-spinel-corundum bearing granulites enclosed in granitic gneisses near Jagtiyal in the Eastern Dharwar Craton (EDC). These granulites are very important in deciphering the prehistory of the thermal peak of metamorphism due to the presence of refractory phases. The appearance of sapphirine is related to the following reactions: (a) Spl(1) + Crd(1) = Spr(1 (2:2:1)) (b) Phl (in Bt(1)) + Crn(1) = East (in Bt(2)) + Spr(2 (7:9:3)) + Crd(2) (c) Bt(2) + Crd(1) + Crn(1) = Spr(2 (7:9:3)) + Kfs + H2O (d) Crd(1) + Spl(1) + Crn(1) = Spr(2 (7:9:3)). The P-T evolution of these sapphirine granulites has been constrained through the use of THERMOCALC program. Temperature of formation of sapphirine-spinel assemblages is high, around 800 A degrees C, and pressure ranges from 5-7 kbars, suggesting that sapphirine formation took place during decompression stage.

• 出版日期2013-7
• 单位中国极地研究中心