摘要
Based on lithology,mineralogy and geochemistry,the generation environment and source for carbonate cements in sandstone reservoirs in the lower position of the Paleogene Lower Ganchaigou Formation in the north of the Mahai Uplift which located in the northern margin of the Qaidam Basin were studied systematically.Two types of calcite cements were found,including xenomorphic micrite and hypidiotopic microcrystalline.The generation of carbonate cements in sandstone reservoirs in the study area might be related to the decarboxylation of organic matters during the early diagenetic stage.