黑龙江新立屯晚三叠世侵入岩地球化学特征及构造环境

Rock Geochemical Characteristics and Tectonic Environment of Late Triassic Intrusive Rocks in Xinlitun of Heilongjiang

新立屯地区位于黑龙江省呼玛县南部宽河中上游,大地构造位置处于西伯利亚板块南缘,兴蒙造山带东段,隶属于大兴安岭中段华力西、燕山期铁、钨、银、金、钼、铜成矿带二十四号桥成矿亚带上。晚三叠世侵入岩由36个岩体组成,由早到晚依次可划分为白云母花岗闪长岩(T_3γδ^(Mu))、白云母二长花岗岩(T_3ηγ^(Mu))、花岗闪长岩(T_3γδ)、似斑状二长花岗岩(T_3ηγ~1)和二长花岗岩(T_3ηγ~2)4个侵入序次,总体展布方向近东西向。岩石化学分析表明,晚三叠世侵入岩形成于板块碰撞前→碰撞后的抬升→同碰撞一个连续的构造过程,与岛弧岩浆作用及陆—陆碰撞有关,岩石成因类型为具有交代成因的I型花岗岩。晚三叠世侵入岩第三、四序次花岗闪长岩和似斑状二长花岗岩与成矿关系密切,在其内接触带容易形成以高温矿化为主的矿体,在其外接触带具有形成多金属矿床的巨大潜力。

Xinli Village is located in the middle and upper reaches of the south of the river in the south of Huma County of Heilongjiang. Its tectonic site is in the southern margin of the Siberian plate and the eastern part of Xingmeng orogenic belt. It belongs to the middle section of Greater Xing＇ an Mountains, Molybdenum, copper metallogenic belt on the 14th bridge metallogenic sub - zone. The intrusive rocks of Late Triassic are composed of 36 rock masses, which can be divided into muscovite granodiorite （T3γδ^Mu）, muscovite long granite （T3ηγ^Mu） , granodiorite （T3γδ） from morning to night （T3ηγ^1）, including the two- long granite （T3ηγ^2）. The general distribution direction is near east- west. The petrological analysis shows that the Late Triassic intrusive rocks are formed before the collision of the plate and the eollision with the collision. A continuous tectonic process is related to the island arc magma and the continental - continental collision. The type of the rock is the epigenetic I type granite. Late Triassic intrusive rocks, the third and fourth order granodiorites and plagioclase - like granites are closely related to mineralization. In the inner contact zone, it is easy to form ore bodies dominated by high temperature mineralization. The belt has the potential to form a polymetallie deposit.