基于微量元素比值分析方法研究川东南地区小河坝组沉积环境和古气候环境

发布时间：2018-06-15 22:44

本文选题：微量元素 + 小河坝组　；参考：《岩矿测试》2017年03期

【摘要】：川东南地区下志留统小河坝组砂岩具有较好的生储盖组合条件,油气地质条件优越,但对其沉积环境为陆相还是海相沉积三角洲的厘定尚不明确。本文针对川东南地区小河坝组亟需解决的沉积环境问题,系统采集了该地区9条典型剖面的74个样品,通过微量元素比值分析方法分析其元素组成,并结合沉积构造特征分析其沉积环境及古气候环境。利用X射线荧光光谱法测试了能判别海陆相沉积环境的Sr、Ba、Mn、Cu等微量元素。结果显示,Sr/Ba平均值为0.2790,最大值为2.31,Mn/Fe值为0.0093~0.0778,Sr/Ca值为0.0005~0.0414,表现为三角洲淡水沉积特征;Sr/Ba平均值小于1,Sr/Cu平均值为4.8758,8.1%样品的Sr/Cu值大于10,总体上反映了小河坝组沉积环境为温润潮湿的古气候环境。
[Abstract]:The sandstones of Xiaoheba formation of Lower Silurian in southeast Sichuan have good assemblage conditions and favorable oil and gas geological conditions, but it is not clear whether the sedimentary environment is continental or marine sedimentary delta. In order to solve the problem of sedimentary environment in Xiaoheba formation in southeast Sichuan, 74 samples of 9 typical sections in this area were collected systematically, and their elemental compositions were analyzed by the method of trace element ratio analysis. The sedimentary environment and paleoclimate environment are analyzed in combination with sedimentary structural characteristics. Some trace elements, such as SrPa-BaMnMn-Cu, which can distinguish the marine and continental sedimentary environment, were measured by X-ray fluorescence spectrometry (XRF). The results show that the average value of Sr- / Ba is 0.2790, and the maximum value is 2.31 Mn-Fe = 0.00933-0.0778nr-Ca = 0.0005- 0.0414, which shows that the average value of Sr- / Ba is less than 1.87588.1wt% of the samples, which reflects that the sedimentary environment of Xiaoheba formation is warm and moist. A moist paleoclimate.
【作者单位】：成都理工大学能源学院;成都理工大学油气藏地质及开发工程国家重点实验室;
【基金】：国家自然科学基金资助项目(41204091)
【分类号】：P532;P618.13

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