准噶尔盆地东缘晚石炭世花岗岩岩石地球化学特征及铀成矿潜力分析

Analysis on lithogeochemical features of Late Carboniferous granite and uranium ore-forming potential at the eastern margin of Junggar Basin

准噶尔盆地东缘将军庙北部花岗岩岩石地球化学特征、稀土元素、微量元素及Sr-Nd-Pb同位素特征显示,该花岗岩形成于碰撞后期板内裂谷环境,其源区主要为软流圈地幔,同时有上地壳物质的混染。初步判定准噶尔盆地东部将军庙地区晚古生代构造环境为成熟岛弧环境,略高于准噶尔盆地平均水平。该地区不同构造单元的古生代大地构造背景及其地壳成熟度存在较大的差异,地壳成熟度整体较低,在一定程度上制约了该区砂岩型铀成矿作用的发育规模。

Characteristics of lithogeochemistry,REE,trace elements and Nd-Sr-Pb isotope of Late Carboniferous granite at the eastern margin of Junggar Basin indicate that granite falls into alkali type which originated from the asthenospheric mantle with upper crust involvement and formed under the setting related to postorogenic setting and a general extension setting in a rift.Although Late Paleozoic crustal maturity of Jiangjunmiao area is higher than the average of whole Junggar Basin,the nonuniformity in tectonic setting and crustal maturity of eastern Junggar Basin has restrained the potential for the sandstone-type uranium mineralization to a certain degree.