华北板块南缘壳内拆离及对大别山北麓逆冲断层系形成的影响

INTRACRUSTAL DETACHMENT IN THESOUTHERN MARGIN OF THE NORTH CHINA PLATE AND ITS INFLUENCE OVER THE FORMATION OF OVERTHRUST SYSTEM IN NORTHRN DABIESHAN

宋子堂

Song Zitang

华北石油地质局地质研究大队 郑州450006

North China Bureau of Petroleum Geology, MGMR

大地电磁测深资料表明,华北板块南缘3～15km深处存在一个高导电世的滑移面,大别山隆起区糜梭岩构造指向、大型褶皱轴面产状及飞来峰、钧遗留的椎覆方向等均表明,自海西晚期以来,华北板块南缘上部地壳(而非整个板块)长期沿此构造面向来做大规格拆离运动。至燕山期,这种运动因大别山强烈隆起而受阻,从而派生出向北边冲的大别山北麓逆冲断层系。

Data of telluric electromagnetic sounding illustrate that there is a sliding plane with highly electric conductivity developed at the depth of 3～5km in the southern margin of the north China plate,In accordance with the directional structures of mylonites,the occurrence of major fold axis plane and sense of tectonic windows and napping emplacement in the Dabie uplifting area,it is suggested a large-scale of southward detachment should have developed along the upper crust of southern margin of the north China plate since the late Hercynian period.Till Yanshan period, this movement was blocked by severe uplifting of the Dabieshan,resulted in the development of northward Dabieshan overthrust system.

https://doi.org/10.11781/sysydz199403250