甘青藏地区现代土壤中有机质类异戊二烯烃来源及地质意义

发布时间：2018-05-07 09:39

  本文选题：甘青藏地区 + 地表土壤　； 参考：《地质论评》2017年01期

【摘要】：本文通过对海拔高度在2500~4500 m的甘肃南部和祁连山、青海东部、西藏东部林中表土、林间表土、森林上限表土、森林下限表土、森林上限高山草甸土,以及青海玉树冬给错纳地区亚高山荒漠—草甸土中可溶有机质正构烷烃分析,利用检测出的类异戊二烯烃的分布特征,对Pr(姥鲛烷)、Ph(植烷)的成因特征进行研究。结果表明,在不同地理环境土壤中均有明显的Pr、Ph存在,Pr/Ph(姥植比)主要为0.6~1.4,平均0.95;Pr/n-C17值主要为0.2-1.2,平均0.64;Ph/n-C18值主要为0.4~1.4,平均0.85。Pr和Ph不仅在水体中生成,在土壤环境中也可以形成。Pr/Ph值与不同生态环境土壤之间没有明确的相关性,但与不同地理区域有一定的联系。在较为温湿的土壤中Pr优势,可能与微生物活动强烈,采用有氧呼吸方式降解有机质有关;干旱、寒冷土壤中Ph优势,可能主要与厌氧发酵有关。由于生成Pr、Ph有机母质及演化途径的差异,以及热演化、成岩过程中的转变,其比值很大程度上影响对沉积盆地原始介质环境信息的判断。
[Abstract]:This paper deals with the forest topsoil, interstand topsoil, upper forest topsoil, forest lower limit topsoil, forest upper limit alpine meadow soil of southern Gansu and Qilian Mountains, eastern Qinghai and eastern Tibet, which have an altitude of 25000 ~ 4500 m above sea level, and the forest upper limit topsoil, the forest lower limit topsoil, the forest upper limit alpine meadow soil. Based on the analysis of normal alkanes of soluble organic matter in subalpine desert meadow soil of Yushu, Qinghai Province, the genetic characteristics of Pr-phane were studied by using the distribution characteristics of isoprene hydrocarbons detected. The results showed that there was a significant presence of Pr-Ph in the soils of different geographical environments. The Pr-pPhratio of Pr-Ph was 0.6 ~ 1.4, the average value of 0.95 Pr-n-C17 was 0.2-1.2, and the average value of 0.64 Ph-n-C18 was 0.40.4.The average 0.85.Pr and Ph were generated not only in the water, but also in the soil. In the soil environment, the value of. Pr- / Ph was not correlated with the soil of different ecological environment, but it was related to different geographical regions. The predominance of pr in warm and wet soils may be related to the strong microbial activity and aerobic respiration to degrade organic matter, while the predominance of Ph in arid and cold soils may be mainly related to anaerobic fermentation. Due to the difference of the organic parent material and the evolution path of Pr-Ph, as well as the thermal evolution and the transformation during diagenesis, the ratio of the organic parent material to Pr-Ph greatly influences the judgement of the environmental information of the original medium in the sedimentary basin.
【作者单位】： 兰州大学地质科学与矿产资源学院(西部矿产资源重点实验室);
【基金】：国家自然科学基金资助项目(编号:NSFC 41571177,41601187,41501209) 中央高校基本科研业务费专项资金(编号:lzujbky-2015-254)的成果~~
【分类号】：S153
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本文编号：1856411