【摘要】：單甲基烷烴是湖相烴源巖飽和烴中常見的支鏈烷烴,其母質(zhì)來源的研究一直存在爭議。對鄂爾多斯盆地上三疊統(tǒng)延長組烴源巖樣品進行了TOC測定、巖石熱解、飽和烴GC-MS和單體碳同位素等分析,并在飽和烴中檢出了豐富的單甲基烷烴化合物。地化分析表明,該區(qū)長7-長10烴源巖的有機質(zhì)類型為Ⅱ-Ⅲ型,C_(29)≥C_(27)規(guī)則甾烷,高等植物的貢獻略微大于低等水生藻類或細菌;單甲基烷烴碳數(shù)分布為C_(12)-C_(32),甲基取代位置以C_2和C_3為主。飽和烴單體碳同位素組成數(shù)據(jù)顯示,姥鮫烷和植烷的δ~(13)C比同碳數(shù)正構(gòu)烷烴重1‰~2‰;同碳數(shù)2-和3-甲基烷烴具有相近的碳同位素組成,表明兩類化合物具有相同物源;單甲基烷烴比正構(gòu)烷烴更富集~(13)C,表現(xiàn)出更大的δ~(13)C值。結(jié)合古環(huán)境等信息表明,鄂爾多斯盆地檢出的單甲基烷烴可能來自于浮游植物或者異養(yǎng)細菌,單甲基烷烴可以作為一種指示生油母質(zhì)的生物標(biāo)志化合物。
[Abstract]:Monomethyl alkanes are common branched alkanes in saturated lacustrine source rocks. The source rock samples of the Upper Triassic Yanchang formation in Ordos Basin were determined by TOC, pyrolysis of rocks, GC-MS of saturated hydrocarbons and single carbon isotopes, and abundant monomethyl alkanes were detected in saturated hydrocarbons. Geochemical analysis shows that the organic matter type of Chang7-Chang10 source rock is type 鈪，

本文編號：2301898