【摘要】 饱和烃气相色谱-质谱联用仪（GC-MS）分析结果显示,黔北坳陷东皇剖面、玉京山剖面下志留统龙马溪组（S1l）烃源岩和黔南坳陷羊跳寨剖面下寒武统牛蹄塘组（?1n）烃源岩中存在C_0–4单金刚烷系列、C_0–3双金刚烷系列、C_0–2三金刚烷系列、C0–1四金刚烷系列和C0–1五金刚烷系列的复杂组合,而在中等成熟的地质样品（镜质组反射率Ro=0.9%～1.4%）中一般仅出现烷基单金刚烷系列或烷基单金刚烷系列与烷基双金刚烷系列的简单组合,表明不同金刚烷类化合物的组合特征是衡量其经历热演化作用强度的定性指标。但黔北坳陷B1井?1n烃源岩和六井剖面上震旦统陡山沱组（Z2ds）烃源岩中缺失此类化合物,这可能与这些老地层经历的热演化作用强度（类镜质组反射率介于4.0%～5.5%之间）超出了金刚烷类化合物的热稳定性极限,并使它们遭到了分解破坏有关。研究区高演化海相烃源岩中金刚烷类化合物的浓度和相关异构体比值均明显高于中等成熟湖相烃源岩,结合类镜质组反射率的实测值判断,表明它们是衡量地质样品中有机质成熟度的有效指标。玉京山剖面S1l烃源岩中高金刚烷类化合物浓度和较低的相关异构体比值,表明此时金刚烷类化合物正大量生成;羊跳寨剖面?1n烃源岩中低的金刚烷类化合物浓度和高的相关异构体比值,说明此时金刚烷类化合物已遭到分解破坏;东皇剖面S1l烃源岩在金刚烷类化合物浓度和相关异构体比值上均介于两者之间,表明此时金刚烷类化合物开始发生明显分解破坏。因此,金刚烷类化合物的组合特征、浓度和相关异构体比值均是反映高演化地区烃源岩有机质成熟度的有效指标。更多还原

【Abstract】 Based on the analytical data of saturated hydrocarbon fractions by gas chromatography-mass spectrometer, a complicated assemblage of C_0–4 adamantanes, C_0–3 diamantanes, C_0–2 triamantanes, C_0–1 tetramantanes, and C_0–1 pentamantanes can be observed in S1 l source rocks from Donghuang and Yujingshan sections in the North Guizhou depression and ?1 n source rocks from Yangtiaozhao section in the South Guizhou Depression. However, there is a simple assemblage of alkyl adamantanes or alkyl adamantanes and alkyl diamantanes in geological samples exhibiting intermediate maturity（Ro=0.9%–1.4%）, suggesting that the assemblage of different diamondoid hydrocarbons is a usefully qualitative indicator to evaluate their maturity. Notably, these diamondoid hydrocarbons are absent in older ?1 n source rocks from B1 well and Z2 ds source rocks from Liujing section in the North Guizhou depression; this is possibly related to their abnormally high maturity（vitrinite-like reflectance values about 4.0%–5.5%）, which results in the decomposition of diamondoid hydrocarbons. Moreover, combined with the reflectance values of vitrinites, concentrations and some isomer ratios of diamondoid hydrocarbons in extracts of highly mature source rocks in the study area are significantly greater than those in source rocks with intermediate maturity, thereby demonstrating that they are a useful indicator to evaluate the maturity of organic matter in geological samples. In S1 l source rocks from Yujingshan section in the North Guizhou Depression, concentrations of various diamondoid hydrocarbons are highest. However, various ratios of different alkyl adamantane and alkyl diamantane isomers are relatively low; this suggests that those rocks are in a thermal evolution stage, which generates significant amount of diamondoid hydrocarbons. In ?1 n source rocks from Yangtiaozhai section in the South Guizhou Depression, concentrations of diamondoid hydrocarbons are lowest. However, the related isomer ratios are highest in the three sections; this implies that diamondoid hydrocarbons have been significantly decomposed in those source rocks. The concentrations of diamondoid hydrocarbons and the related isomer ratios in S1 l source rocks from Donghuang section in the North Guizhou Depression are between those of the two sections mentioned above, suggesting that diamondoid hydrocarbons have begun to decompose in those source rocks. Therefore, assemblages, concentrations, and different isomer ratios of diamondoid hydrocarbons are useful maturity indicators for highly thermal source rocks.更多还原