[关键词]
[摘要]
本文利用德国Wissel公司生产的新型穆斯堡尔谱仪(Bench-MB500)对山东龙口常庄子村北黄县弧形断裂断层剖面上的多种断层泥样品进行了穆斯堡尔谱测试分析,讨论了该断层剖面上铁元素地球化学分布特征及其地震地质意义。结果显示,该断裂中央部分比较年轻的断层泥相对富集para-Fe2+,而两侧较老的断层泥基本由para-Fe3+组成;剖面断层泥样品中铁元素的地球化学特征与断层的活动演化历史密切相关,显示了断裂带内存在复杂的水岩相互作用。
[Key word]
[Abstract]
Fault gouge has potential implications in the study of fault actions because such tectonic materials are normally produced with fault activity. The distribution of para-Fe2+ and para-Fe3+ in the fault gouge produced by the fault activity of different times reflects different Oxidation and reduction environment,which provides the possibility to study the activity of the fault. Various gouge samples were collected from a naturally outcropped profile of the Huangxian Arc-type Fault at the Changzhuzi Beicun of Huangxian Country,Shandong Province,and analyzed for iron species using a Bench-MB500 Wissel M ssbauer Spectroscopy. Based on the general tectonic properties and activity identification of the fault,and fault materials for active times,the characteristics of iron speciation of the fault materials and their significance to seismic geology were discussed in this paper. All evidence revealed that the central part of the relatively younger fault gouge was rich in high-spin paramagnetic ferrous iron(para-Fe2+)whereas the relatively older gouge on two sides were mainly composed of low-spin paramagnetic ferric iron(para-Fe3+). All geochemical properties of iron in the fault gouge samples showed close relationship to the evolution and activity history of the fault,indicating some complexed water-rock interactions occurred within the fault zone. Those results will supply a new method for the analysis of newly-old orders of faults and their active processes by using the elemental geochemical properties of iron in fault materials,and also showing valuable distribution and implications.
[中图分类号]
P315
[基金项目]
“十二五”国家科技支撑计划项目-郯庐地震断裂带中段地震活动规律及地震危险区判定研究专题(2012BAK19B04-01)和国家自然科学基金课题-陇南地区大型滑坡滑带土形成与聚集的地球化学研究(41572352)