| 摘要: |
| 以青岛八仙墩碎屑岩样品中微量元素测试结果为基础, 结合碎屑岩沉积构造等方面的证据, 选用对沉积环境反映比较敏感的Sr、Ba、Th、U、V、Ni 等微量元素指标, 分析地层中微量元素含量及微量元素之间比值与沉积环境之间的对应关系, 探讨了八仙墩碎屑岩的沉积环境。水平层理、冲洗交错层理、丘状交错层理和洼状交错层理等沉积构造以及浊积岩的鲍马序列都指示八仙墩碎屑岩为海相成因。八仙墩碎屑岩中的Sr/Ba(0.42～4.16, 平均值为0.78) , Th/U (3.82～6.78, 平均值为4.88),V/(V+Ni)(0.75～0.95, 平均值为0.82)和弱的Ce 负异常表明八仙墩碎屑岩是在还原环境条件下形成的海相碎屑岩。被崂山花岗岩侵入, 以及本套地层底部、来自苏鲁高压-超高压变质带的花岗片麻岩砾石, 说明八仙墩碎屑岩形成于中生代, 是一套中生代的海相地层。本套碎屑岩指示南黄海盆地深部应有相应的海相浊积岩地层, 是良好的油气储层, 对南黄海海相地层油气勘探具有重要的指示意义。 |
| 关键词: 青岛八仙墩 微量元素 沉积环境 海相碎屑岩 中生代 |
| DOI：10.11759/hykx20121121001 |
| 分类号: |
| 基金项目:国家自然科学基金(41206051) |
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| Trace element geochemical characteristics of the marine clastic rocks in Qingdao and their sedimentary environments implications |
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| Abstract: |
| The sedimentary environment of the clastic rocks from Baxiandun, Qingdao was studied through identifying the corresponding relationships between trace element compositions and sedimentary environments. The results showed that some special trace elements such as Sr, Ba, Th, U, V and Ni, were very sensitive to the sedimentary environment. Horizontal bedding, swash bedding, hummocky cross bedding and swaley cross bedding and Boume Sequences in the clastic rocks from Baxiandun indicated that it formed in marine environment. Sr/Ba values (0.42～4.16, average 0.78), Th/U values (3.82～6.78, average 4.88) and V/(V + Ni) values (0.75～0.95, average 0.82) and the weak negative Ce anomalies in the Baxiandun clastic rocks showed that the clastic rocks formed in marine environment which was under the reducing conditions. Intruded by Laoshan Granite and the granitic gneiss gravels at the bottom of this stratum, which came from the Sulu UHP metamorphic belt, it is illustrated that the Baxiandun clastic rocks formed in the Mesozoic. The clastic rocks indicated possible existence of corresponding beds with potential oil-gas reservoir beneath the South Yellow Sea. |
| Key words: Baxiandun, Qingdao trace element sedimentary environment marine clastic rock Mesozoic |
