摘要：
海拉尔盆地乌尔逊凹陷南屯组与松辽盆地孤店CO2气田泉头组发育大量含片钠铝石砂岩。通过偏光显微镜、扫描电镜、茜素红-S染色、X射线衍射、电子探针与INCA能谱分析等，对含片钠铝石砂岩的骨架碎屑组分、胶结物与自生矿物、成岩共生序列等岩石学特征进行了系统研究。研究表明，含片钠铝石砂岩的岩石类型为长石砂岩和岩屑长石砂岩，粒度以细粒、细—中粒为主，分选差—中等。砂岩中胶结物主要为次生加大石英、自生石英、片钠铝石、铁白云石和粘土矿物。其中，片钠铝石最高可达砂岩总体积的22％在砂岩中或以放射状、束状、菊花状、杂乱毛发状、毛球状、板状等集合体充填孔隙，或呈束状和板状交代长石和岩屑。电子探针与INCA能谱综合分析表明，片钠铝石主要由Na、Al、O、C等组成。在含片钠铝石砂岩中，成岩共生序列依次为粘土矿物包壳—次生加大石英、自生石英、自生高岭石—油气充注—CO2充注—片钠铝石—铁白云石。其中，CO2注入前形成的自生矿物组合主要为次生加大石英、自生石英和自生高岭石，CO2注入后形成的自生矿物组合主要为片钠铝石和铁白云石。
Abstract:
Both the Nantun Formation in the Wuerxun Sag of the Hailaer Basin and the Quantou Formation in the Gudian CO2 Gasfield in the southern Songliao Basin contain abundant dawsonitebearing sandstones. The petrologic characteristics of these sandstones including the framework clastic composition，cements and authigenic minerals and diagenetic paragenesis succession are investigated through polarizering microscope，scanning electron microscope，alizarin redstaining，Xray diffraction，electron probe and INCA energy spectrum analysis etc. The results show that these sandstones are finegrained or finetomediumgrained，poorly to moderately sorted arkoses and lithic arkoses. The dominant cements are secondary quartz overgrowths，authigenic quartz，dawsonite，ankerite and clay minerals. The amount of dawsonite is higher(up to 22％ of the total volume of the sandstones)，either as cements，filling intergrain pores as radial，bunchy，rosette，intricately trichoid，spheric and platy collectives，or as replacement of feldspar and lithic grains with bunchy and platy shapes. Dawsonite is mainly composed of elements such as Na，Al，O，and C according to electron probe and INCA energy spectrum analyses. The paragenetic sequence includes(1)clay mineral coatings;(2)secondary quartz overgrowths，authigenic quartz，authigenic kaolinite;(3)petroleum charging;(4)CO2 charging;(5)dawsonite;and (6)ankerite. The authigenic minerals formed before CO2 charging include secondary quartz overgrowths，authigenic quartz and authigenic kaolinite，while the main cements formed after CO2 charging are dawsonite and ankerite.
高玉巧 刘 立曲希玉刘 娜. 海拉尔盆地乌尔逊凹陷与松辽盆地孤店CO2气田含片钠铝石砂岩的岩石学特征[J]. 古地理学报, 2008, 10(2): 111-123.
Gao Yuqiao Liu Li Qu Xiyu Liu Na. Petrologic characteristics of dawsonitebearing sandstones in Wuerxun Sag of Hailaer Basin and Gudian CO2 Gasfield in Songliao Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2008, 10(2): 111-123.