摘要
贵州瓮安水银山的下寒武统底部的磷块岩的生物标志物以及单体烃碳同位素分析表明,正构烷烃以nC17和nC27为优势,无奇偶优势;Pr/Ph为0.95,显示弱的植烷优势;萜烷丰度顺序为五环三萜烷>三环萜烷>四环萜烷;规则甾烷呈不对称的"V"字形分布,表现为C29>C27>C28的分布特征。正构烷烃的单体碳同位素值随碳数增加的曲线变化略显平缓,变化范围较窄(-31.13‰～-33.14‰)。这些生物标志物和单体烃碳同位素的特征表明,贵州瓮安水银山磷块岩中生物母源主要是低等的水生藻类的输入,高含量伽玛蜡烷和三环萜烷以及Ts/(Ts+Tm)比值为0.37(<0.5)的特征表明深部温盐流上涌是形成这套磷块岩的主要原因。
By means of GC-MS,a lot of biomarkers of n-alkanes,isoprenoid,teranes and terpanes were detected from phosphorite occurred in the bottom of the 1 Niutitang Formation of Early Cambrian,in the Weng＇an area of Guizhou Province. The n-alkanes of phosphorite showed carbon molecular components with highest peaks of nC17 and nC27,without odd-even carbon dominance. The ratio of pristine/phytane of 0.95 indicated that the sample possessed phytane dominance. Terpanes distribution patterns of samples were pentayclic terpanes〉tricyclic terpanes〉tetracyclic terpanes. Regular steranes consist mainly of C27-steranes,C28-steranes and C29-steranes and its pattern showed asymmetric ＂V＂ distribution. According to abundance,C29-steranes〉C27-steranes〉C28-steranes were identified. The carbon isotope of individual hydrocarbons in phosphorite showed narrow bound （--31.13‰--33.14‰）. The biomarkers and carbon isotope of individual hydrocarbons analyses indicated that organic matter was originated from heterotrophic bacteria. 1 and phototrophic algae. High content of gammacerane and tricyclic terpanes and the ratio of Ts/ （Ts＋Tm） （0.37） demonstrated that the phosphorite in the bottom of Niutitang Formation of Early Cambrian was mainly resulted from the upwelling of warm, saline and deep seawater.
出处
《矿物岩石》
CAS
CSCD
北大核心
2010年第1期93-98,共6页
Mineralogy and Petrology
基金
国家自然科学基金(40472013,40743016)
教育部“高等学校博士学科点专项科研基金”(20070616014)
贵州瓮福大信北斗山磷矿项目
中国石油化工海相油气勘探前瞻性项目(G0800-06-ZS-319)
关键词
生物标志物
单体烃碳同位素
上升流
早寒武世牛蹄塘组
贵州瓮安
biomarkers
carbon isotope of individual hydrocarbons
upwelling
Early Cambrian Niutitang Formation
Weng＇an in Guizhou Province
