Organic matter analysis of surface sediment in Buha Estuary region and its comparative sedimentology significance
Organic matter analysis of surface sediment in Buha Estuary region and its comparative sedimentology significance
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DOI：
10.18307/2017.0524
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
W. Yaqiong;Wang Chang-yong;Meng Xianghao;Liu Wenwu;Zhou Yi;Chang Hailiang
中科院分区：
文献类型：
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作者：
W. Yaqiong;Wang Chang-yong;Meng Xianghao;Liu Wenwu;Zhou Yi;Chang Hailiang
青海湖布哈口晚三叠世古地理特征和水环境与鄂尔多斯盆地和四川盆地相似。研究布哈河口表层沉积物有机质类型及其丰度，对比较沉积学具有重要意义。对布哈河口地区河流、前三角洲、湖滨、浅湖和半深湖沉积物进行了全岩组成分析、总有机碳（TOC）分析和干酪根检测。结果表明，沉积物中主要存在II2型干酪根，少量存在II1型干酪根。沉积物中TOC含量不超过4.29%，半深湖样品TOC含量普遍较高，有机质质量优于其他地方。沉积物中粘土矿物含量、有机质生产力和水深是影响布哈河口沉积物TOC含量的主要因素。半深湖是一种生产力高、有机质条件好的沉积环境，是最有利的烃源地。同时，根据前三角洲、浅湖和半深湖沉积物中TOC含量与水深之间的良好相关性，建立了TOC含量重建水深的公式。
The paleogeography characteristics and water environment of Buha Estuary in Lake Qinghai are similar with those in Or⁃ dos Basin and Sichuan Basin in the Late Triassic. The study on the types of organic matter and its abundance in the surface sedi⁃ ment from Buha Estuary is significant to comparative sedimentology. The sediments were collected from river, prodelta, lakeshore, shallow lake and semi⁃deep lake in Buha Estuary region and were analyzed in aspects of whole⁃rock composition analysis, total or⁃ ganic carbon (TOC) and examination of the kerogen. The results demonstrate that II2 kerogen is the major organic matter type in sediments and only a few II1 kerogen exist. TOC content in the sediments is no more than 4.29% , and the samples collected from semi⁃deep lake generally have high TOC content while the quality of organic matter is better than that of the other places. The clay minerals content in sediments, organic matter productivity and water depth are the major factors that affect the TOC content in the sediments of Buha Estuary. The semi⁃deep lake is a sedimentary environment which was the most favorable hydrocarbon source place because of its high productivity and good condition for organic matter. At the same time, according to the good correlation be⁃ tween the water depth and TOC contents in sediments gathering from prodelta, shallow lake and semi⁃deep lake, the formula using the TOC contents has been established for reconstructing water depth.