GEOCHEMICAL CHARACTERISTICS OF JADEITE QUARTZITE IN THE DABIE MOUNTAIN, ANHUI PROVINCE AND THEIR GEOLOGICAL IMPLICATIONS
WU Zheng;LI Shuang-ying;School of Resource and Environmental Engineering, Hefei University of Technology;
Jadeite quartzite is an important member of the ultrahigh pressure metamorphic belt of the Dabie Mountain. The average contents of main elements in jadeite quartzite are 72.73% for SiO_2, 11.77% Al_2O_3, 1.61%MgO, 5.00% Fe_2O_3, 5.45% Na_2 O, 0.22% K_2 O and 0.59% TiO_2, showing remarkable Si-Fe-Na-rich features.Average contents of characteristic trace elements are 10.12 x10~(-6) for Th, 1.94 x10~(-6) U, 10.91 x10~(-6) Hf, 7.68 x10~(-6) Sc, 437.05 x10~(-6) Zr, 15.81 x10~(-6) Nb, 45.36 x10~(-6) Y, 141.88 x10~(-6) Ba, 30.07 x10~(-6) Sr; 5.18 Th/U, 1.56 Th/Sc, 9.50 La/Sc;the average content of ΣREE is 223.07 x10~(-6),(La/Yb)N 7.01, Eu=0.61, distinct negative anomaly of Eu. Protolith reconstruction result is sodium-rich graywacke, which possibly formed in the Paleoproterozoic active continental margin of the Yangtze continental plate, and suffered ultra-high pressure metamorphism during the process of collision with North China Plate in Mesozoic Triassic.
【CateGory Index】： P588.3