滇西昌宁更戛乡下泥盆统向阳寺组硅质岩地球化学特征及构造环境探讨
发布时间：2018-10-15 12:07
【摘要】：滇西昌宁更戛乡下泥盆统向阳寺组位于冈瓦纳大陆与泛华夏大陆间昌宁—孟连结合带北段西侧。文章首次发现向阳寺组中存在硅质岩,并对其硅质岩的地球化学特征等进行了深入研究。硅质岩中发育海百合茎、放射虫及硅藻。地球化学分析表明,向阳寺组硅质岩Si O2质量分数为85.43%~93.50%,Al/(Al+Fe+Mn)平均值为0.77,处于生物成因范畴;硅质岩稀土元素分析结果为其REE总量平均值为53.208×10-6,稀土元素北美页岩标准化配分曲线相对平坦,δCe平均值为1.02,δEu平均值为1.01,LaN/CeN平均值为0.99,LaN/YbN平均值为0.84,表明硅质岩形成于近大陆边缘的深海沉积环境。随着早泥盆世昌宁—孟连洋的快速扩张,保山地块边缘区域性同沉积断裂发育,造成了更戛乡向阳寺组大面积的硅质岩沉积。结合硅质岩地球化学特征的分析与古生物研究,认为更戛乡向阳寺组硅质岩属冈瓦纳大陆保山地块边缘亲昌宁—孟连古特提斯洋的深海沉积的产物。
[Abstract]:The Xiangyangsi formation of Lower Devonian system is located on the west side of Changning-Menglian combination belt between Gondwana continent and pan-China continent. In this paper, siliceous rocks are found in Xiangyangsi formation for the first time, and the geochemical characteristics of siliceous rocks are studied. The stem of sea lily, radiolaria and diatom are developed in siliceous rock. Geochemical analysis shows that the mass fraction of Si O 2 in siliceous rocks of Xiangyangsi formation is 85.43% and 93.50% Al / (Al Fe Mn) average is 0.77, which is within the scope of biogenesis. The results of REE analysis of siliceous rocks show that the average value of total REE is 53.208 脳 10-6, the normalized partition curve of REE North American shale is relatively flat, 未 Ce average is 1.02and 未 Eu average is 1.01L LaN / CeN mean value is 0.84, indicating that siliceous rocks were formed in near. The deep-sea sedimentary environment on the continental margin. With the rapid expansion of the early Devonian Shichang Ning- Menglian Ocean, the regional synsedimentary faults on the margin of Baoshan block developed, resulting in a large area of siliceous deposits in Xiangyangsi formation in the town of Gansa. Based on the analysis of geochemical characteristics of siliceous rocks and paleontological study, it is considered that the siliceous rocks of Xiangyangsi formation in Gangwang are the product of deep-sea deposits in the margin of the Baoshan block in Gondwana continent, from the Pro-Changning and Menglian paleoTethys oceans.
【作者单位】： 成都理工大学地球科学学院;四川省地矿局区域地质调查队;
【基金】：四川省教育厅项目(80303-KZY006) 中国地质调查局地质调查工作项目(12120113048700) 成都理工大学国土资源部构造成矿成藏重点实验室及成都理工大学矿物学、岩石学、矿床学国家重点(培育)学科联合资助~~
【分类号】：P588.244
[Abstract]:The Xiangyangsi formation of Lower Devonian system is located on the west side of Changning-Menglian combination belt between Gondwana continent and pan-China continent. In this paper, siliceous rocks are found in Xiangyangsi formation for the first time, and the geochemical characteristics of siliceous rocks are studied. The stem of sea lily, radiolaria and diatom are developed in siliceous rock. Geochemical analysis shows that the mass fraction of Si O 2 in siliceous rocks of Xiangyangsi formation is 85.43% and 93.50% Al / (Al Fe Mn) average is 0.77, which is within the scope of biogenesis. The results of REE analysis of siliceous rocks show that the average value of total REE is 53.208 脳 10-6, the normalized partition curve of REE North American shale is relatively flat, 未 Ce average is 1.02and 未 Eu average is 1.01L LaN / CeN mean value is 0.84, indicating that siliceous rocks were formed in near. The deep-sea sedimentary environment on the continental margin. With the rapid expansion of the early Devonian Shichang Ning- Menglian Ocean, the regional synsedimentary faults on the margin of Baoshan block developed, resulting in a large area of siliceous deposits in Xiangyangsi formation in the town of Gansa. Based on the analysis of geochemical characteristics of siliceous rocks and paleontological study, it is considered that the siliceous rocks of Xiangyangsi formation in Gangwang are the product of deep-sea deposits in the margin of the Baoshan block in Gondwana continent, from the Pro-Changning and Menglian paleoTethys oceans.
【作者单位】： 成都理工大学地球科学学院;四川省地矿局区域地质调查队;
【基金】：四川省教育厅项目(80303-KZY006) 中国地质调查局地质调查工作项目(12120113048700) 成都理工大学国土资源部构造成矿成藏重点实验室及成都理工大学矿物学、岩石学、矿床学国家重点(培育)学科联合资助~~
【分类号】：P588.244
【相似文献】
相关期刊论文 前10条
1 钱存超，，黄俊;安徽大别山地区首次发现硅质岩[J];中国区域地质;1995年03期
2 谢桂青,胡瑞忠,方维萱,漆亮;云南墨江金矿床硅质岩的地质地球化学特征及其意义[J];矿物学报;2001年01期
3 杨志军,周永章,张澄博,付伟,杨海生;硅质岩组构信息研究及其意义[J];矿物岩石地球化学通报;2003年03期
4 王卓卓;陈代钊;汪建国;;广西南宁地区泥盆系硅质岩地球化学特征及沉积环境[J];沉积学报;2007年02期
5 任国选;孟祥化;葛铭;王德海;郭峰;;蓟县地区雾迷山组风暴硅质岩沉积序列[J];地质科技情报;2007年05期
6 李晓彪;罗远良;罗泰义;周明忠;;重庆城口地区早前寒武系黑色岩系研究:(2)早寒武世硅质岩的沉积环境研究[J];矿物学报;2007年Z1期
7 闫臻;李继亮;雍拥;肖文交;王宗起;向永生;;北祁连石灰沟奥陶纪碳酸盐岩—硅质岩形成的构造环境[J];岩石学报;2008年10期
8 徐跃通;浙江西裘晚元古代层状硅质岩热水沉积地球化学标志及其沉积环境意义[J];地球化学;1996年06期
9 颜泽p
本文编号：2272507
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2272507.html
