鲁西隆起重磁异常特征及其构造活动性分析  

Gravity-magnetic anomalies and tectonic activities in Luxi uplift

作　　者：于磊 张健 高玲举 董淼 

机构地区：[1]山东省水土保持与环境保育重点实验室,中国山东临沂276000 [2]临沂大学资源环境学院,中国山东临沂276000 [3]中国科学院大学地球科学学院,中国北京100049

出　　处：《地震学报》2017年第5期694-707,共14页Acta Seismologica Sinica

基　　金：国家自然科学基金(41601555);山东省自然科学基金(6011701512);临沂大学博士启动专项基金(LYDX2016BS035)共同资助

摘　　要：通过对鲁西隆起区重磁资料的分析和反演计算,研究了沂沭断裂带、齐河—广饶断裂带、聊城—兰考断裂带、丰沛断裂带以及地块内部断裂的重磁异常、莫霍面和居里面深度特征,并讨论了鲁西隆起的地质构造特征和构造活动性.结果显示:鲁西隆起基底广泛出露,沉积层主要分布在由断裂下降盘控制的凹陷内,区内断裂深度达20km以上,其中蒙山断裂深入至上地幔,控制了蒙山金伯利岩型金刚石矿的产出;鲁西隆起区莫霍面深度为30—35km,整体呈向西开口的箕形,地块中部地壳厚度较厚,除西侧地壳呈阶梯状增厚外隆起地块四周地壳逐渐减薄;居里面深度介于20—33km之间,中部地区较深,为整体稳定的地块,断裂带分布位置对应于居里面梯度带;地震活动主要集中于断裂带与莫霍面梯度带交会区以及断裂带上的居里面突变区.Luxi uplift has complex geological conditions and well-developed faults.By analyzing and calculating the gravity and magnetic data in this area,we studied the characteristic of gravity-magnetic anomalies,Moho discontinuity and Curie isothermal surface on the Yishu fault zone,Qihe-Guangrao fault zone,Liaocheng-Lankao fault zone,Fengpei fault zone and the uplift block,as well as the geological tectonic features and tectonic activity of this area.The results show that basement of Luxi uplift is widely exposed,and sediments are mainly distributed in the sags which are controlled by the down-thrown side of faults.Faults depth of this area can reach up to more than 20 km,and one of them is a regional upper mantle deep structure named Mengshan fault.Mengshan fault controls output of the kimberlite-type diamond.The depth of Moho discontinuity in this area varies from 30 km to 35 km,and it features a dustpan shape which is open to the west.The central block is thick and the surrounding areas are gradually thinning except for the west part which is stepped thickening.The Curie isothermal surface depth ranges from 20 km to 33 km with an average of 26 km.The Curie depth of the central area is deeper than its surrounding areas,and it is a stable block.The fault zones correspond to the Curie surface gradient zones.The earthquake activities mainly focus on the areas where the fault zones meet with Moho discontinuity gradient zones,as well as the fault zone where Curie surface changes abruptly.

关 键 词：鲁西隆起 重磁反演 构造活动性 地壳结构 莫霍面 居里面 

分 类 号：P315.2[天文地球—地震学]