长直链烷基苯的异常分布及其成因探讨

ANOMALOUS DISTRIBUTION OF LONG-STRAIGHT CHAIN ALKYLBENZENES AND THEIR ORIGIN

来自楚雄盆地三叠系地层的三个沥青样品长直链烷基苯在C16～C20范围内具强烈的偶碳优势。正构烷烃和烷基环己烷与烷基苯分布的差异表明:偶碳数烷基苯不可能来自直链脂肪酸,也不可能来自一些细菌和某些藻类生物体中的环己基脂肪酸,它可能是成岩作用阶段,在矿物催化作用下偶数碳醇与生物体中简单的芳烃化合物进行烷基化反应抑或是在深成作用早期,长链偶碳数伯醇通过自由基反应与存在于干酪根中苯进行烷基化作用而形成。烷基苯这一分布特征与热演化没有相关关系。

The longstraight alkylbenzenes in three bitumen samples from the Triassic of the Chuxiong Basin show a strong even to odd preference The distribution differences between nalkane, alkylcyclohexane and alkylbenzene revealed that alkylbenzene with even carbon number is derived neither from straightchain fatty acid nor from cyclohexyl fatty acid It may have resulted from the reaction of primary alcohol of even carbon number with the simple aromatic compounds, which were found in many organisms during the diagenetic stage with the help of catalyst, or from the reaction of free radicals between the longstraight primary alcohol of even carbon number and the benzene coated on kerogen during the early stage of catagenesis There is no relationship of the specific distribution of alkylbenzenes with thermal evolution