辉绿岩侵位对半固结砂岩的改造作用--以松辽盆地东南部下白垩统为例

在偏光显微镜和扫描电镜下，发现辉绿岩．砂岩接触带附近半固结的长石砂岩中石英颗粒边部、颗粒间孔隙内及颗粒内裂隙中微晶石英发育．不论是纵向上还是横向上，距接触带较近的样品中，微晶石英多而细长．随着远离接触带，石英微晶逐渐减少，形状逐渐变的粗短．研究表明，这些微晶石英是辉绿岩侵位对围岩砂岩中碎屑石英的压溶或重结晶等作用形成的．

ALTERATION TO SEMI-CONCRETED SANDSTONE BY DIABASE INTRUSION--TAKING AN EXAMPLE FROM THE CRETACEOUS IN THE SOUTHEAST OF SONGLIAO BASIN

By means of microscope and SEM, microcrystalline quartz is abundantly found at the brim of detrital quartz, in the hole among grains or inner fracture of grains in the semi-concreted feldspathic sandstone near the intrusion belt between diabate and sandstone. In the samples near the intrusion belt, microcrystalline quartz is abundant and slender not only vertically but also horizontally. With the increasing distance from the intrusion belt, the number of microcrystalline is reduced gradually and the shape becomes wider and shorter. It is showed that diabase intrusion can lead to pressolution of adjacent rock, so fracture, wider microcrystalline and overgrowth of quartz formed. On the other thing, diabase intrusion can quicken quartz dissolution, so the slender microcrystalline quartz came into being near intrusion belt where solution converged and crystallized with high speed. It is indicated that magma intrusion betters greatly properties of deep reservoir according to the exploration of petroliferous basins in the east of China.