Discovery of Xiaogulihe perpotassic basic and ultrabasic volcanic rock in the north-west Heilongjiang province, China
A suite of basic to urtrabasic per-potassic volcanic rocks in the north part of Wudalianchi rift belt, Heilongjiang province are reported in this paper. On the basin of detailed field investigation, eruption sequence of the volcanic rocks has been identified and was confirmed that they are evolved from basic to urtrabasic with the contant of K_2O and TiO_2 progressively. Such observation leads to a preliminary conclusion about the origin of the ultrabasic- per-potassic rocks, i. e. instead of the resuslt of crystal fractionation of a parental magma, they are produced in an independent typhonic magmatic events against a tectonic background of rift evolution. The Xiaogulihe urtrabasic-perpotassic volcanic rocks were compared with famous potassic volcanic rocks in world as Uganda and Italy etc.