辽西拗陷凌源地区洪水庄组烃源岩生物标志化合物特征及意义

应用气相色谱、气相色谱-质谱技术，分析烃源岩的有机质来源、沉积环境、热演化程度等信息.研究表明：洪水庄组烃源岩样品的正构烷烃分布图（m/z85）以"前峰型"的单峰态分布为主，主峰碳多为nC18，表明有机质来源以低等生物为主.三环萜烷呈C20或C23为主峰的正态分布，C24四环二萜/C26三环萜烷比值分布于0.35~1.38，平均值为0.65，表明洪水庄组为低等生物输入.洪水庄组烃源岩甾烷呈现C27甾烷占优势的"L"型，表明生烃母质来源为低等水生生物.Pr/Ph比值为0.16~0.85，植烷优势较明显，指示为强还原环境，少部分为还原环境.伽马蜡烷指数（Ga/C30H）为0.06~0.66，平均值0.21，反映洪水庄组烃源岩形成于半咸水环境.甾烷C29-αββ/（αββ+ααα）值介于0.26~0.46，平均为0.42，表明洪水庄组烃源岩多数处于成熟阶段.

CHARACTERISTICS AND SIGNIFICANCE OF BIOMARKER COMPOUNDS IN SOURCE ROCKS OF HONGSHUIZHUANG FORMATION IN LINGYUAN AREA,WESTERN LIAONING DEPRESSION

Gas chromatography(GC) and gas chromatography-mass spectrometry(GC-MS) are used to analyze the organic matter sources, sedimentary environment and thermal evolution degree of source rocks. The results show that the distribution of n-alkanes(m/z85) of source rocks from Hongshuizhuang Formation is dominated by front peak type unimodel. The main peak carbon is mostly nC18, indicating the organic source is mainly lower organism. The tricyclic terpenes show a normal distribution with C20 or C23 as the main peak, and the ratio of C24-tetracyclic diterpenes/C26 tricyclic terpenes is 0.35-1.38, averagely 0.65, indicating that there is input of lower organism in Hongshuizhuang Formation. The steranes show the dominant C27 sterane L-shape distribution, suggesting that the source of hydrocarbon generation material be lower aquatic organism. The Pr/Ph ratio is 0.16-0.85, with obvious phytane predominance, indicating a strong reducing environment and partially reducing environment. The gammacerane index(Ga/C30H) is 0.06-0.66, averagely 0.21, reflecting the source rocks were formed in brackish water environment. The Sterane C29-αββ/(αββ+ααα) is 0.26-0.46, averagely 0.42, showing the source rocks are mostly in the mature stage.