松辽盆地南部红岗油田青山口组片钠铝石的结晶特征及成因探讨

松辽盆地南部红岗油田青山口组发育大量含片钠铝石砂岩。含片钠铝石砂岩的岩石类型为长石岩屑砂岩和岩屑长石砂岩，砂岩中的胶结物主要为次生加大石英、方解石、片钠铝石、铁白云石和粘土矿物，成岩共生序列为粘土包壳-方解石-石英次生加大-片钠铝石-铁白云石-沥青。其中，片钠铝石多以放射状、栉状、板状等集合体充填孔隙，少量以杂乱状和板状交代长石和岩屑，且交代的碱性长石多于斜长石；此外，孔隙中的放射状片钠铝石开始生长时多呈团簇状，随埋深的增大，放射状及栉状片钠铝石的晶体平均粒度变大，板状片钠铝石的含量也增加;而片钠铝石的总含量则先增加后减少，片钠铝石的结晶特征及其含量与成岩流体的温度的高低、pH值的大小以及CO₂分压的高低等密切相关。

Crystal Characteristics and Genesis of Dawsonite of the Qingshankou Formation in the Honggang Oilfield in the Southern Songliao Basin

The Qingshankou Formation in the Honggang oilfield in the southern Songliao basin contains abundant dawsonite-bearing sandstones.The results show that these sandstones are arkoses and lithic arkoses.The dominant cements are secondary quartz overgrowths,calcite,dawsonite,ankerite and clay minerals.Dawsonite,either as cements,filling inter-grain pores as radial,comb and platy collectives,or as replacement of feldspar and lithic grains with intricately trichoid and platy shapes,and alkaline feldspar replaced b...