网络出版日期: 2014-08-15
基金资助
国家自然科学基金项目“致密砂岩气藏形成的流体动力学机制”(编号:41102085)和国家重点基础研究发展计划(973)项目“中国 西部叠合盆地深部油气复合成藏机制与富集规律”(编号:2011CB201100)联合资助
Carbon and oxygen isotope analysis method for dolomite formation mechanism: A case study from Proterozoic dolomite in Yanshan area
Online published: 2014-08-15
北京燕山地区元古界高于庄组—雾迷山组发育了大量的白云岩,但有关其成因机理仍认识不清。选择十三陵地区白云岩较为发育的高于庄组、杨庄组和雾迷山组进行取样研究,并采用碳氧同位素分析测试方法,对所取样品进行古盐度和古温度的恢复分析,得到如下结果:高于庄组δ13C 值平均为 -1.13‰, δ18O 值平均为 -7.87‰,Z值平均为 122.188 5,平均成岩温度为 51.85 ℃;杨庄组δ13C 值平均为 -0.93‰, δ18O 值平均为 -6.11‰,Z值平均为 122.434 8,平均成岩温度为 47.82 ℃;雾迷山组δ13C 值平均为 0.13‰, δ18O 值平均为 -4.60‰,Z值平均为 125.370 7,平均成岩温度为 39.48 ℃。 对上述结果分析表明,该区雾迷山组白云岩主要为准同生白云石化作用所形成,杨庄组白云岩为混合白云石化作用所形成,高于庄组白云岩成因较为复杂,既有回流渗透白云石化作用,也有混合白云石化作用。
张水山 , 张三元 , 周红艳 , 易小芹 . 白云岩成因碳氧同位素分析方法初探———以北京燕山地区元古界白云岩为例[J]. 岩性油气藏, 2014 , 26(4) : 117 -122 . DOI: 10.3969/j.issn.1673-8926.2014.04.017
Dolomites are well developed in Gaoyuzhuang Formation to Wumishan Formation in Yanshan area, Beijing. However, the understanding of dolomite genesis in this area is still unclear. This paper used carbon and oxygen isotope analysis to carry out reconstruction of ancient salinity and ancient temperature of the dolomite samples selected from Gaoyuzhuang Formation, Yangzhuang Formation and Wumishan Formation in the Ming Tombs area. The result shows that in Gaoyuzhuang Formation, the mean of δ13C is -1.13‰, the mean of δ18O is -7.87‰ , the mean of Z is 122.188 5, and the average diagenetic temperature is 51.85 ℃; in the Yangzhuang Formation, the mean of δ13C is -0.93‰, the mean of δ18O is -6.11‰ , the mean of Z is 122.434 8, and the average diagenetic temperature is 47.82 ℃; in Wumishan Formation, the mean of δ13C is 0.13‰, the mean of δ18O is -4.60‰ , the mean of Z is 125.370 7, and the average diagenetic temperature is 39.48 ℃. According to the analysis of the above results, we concluded that most dolomites of Wumishan Formation were mainly resulted from penecontemporaneous dolomitization, and dolomites of Yangzhuang Formation were resulted from dorag dolomitization. The dolomite genesis of Gaoyuzhuang Formation is more complicated, which includes not only seepage reflux dolomitization but also dorag dolomitization.
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