A study on fracture orientation and characteristic of remnant paleomagnetization of deep-burial volcanic rocks, north of the Songliao Basin
松辽盆地北部深层火山岩剩磁特征与裂缝定向研究

Systematic analysis on isothermal remnant magnetization and thermal demagnetization displays that the deep-burial early Cretaceous volcanic rocks in the north of the Songliao Basin have two groups of stable remnant magnetization components comprising characteristic remnant magnetization and viscous remnant magnetization, with magnetite as the mineral carrying remanence. The direction of corrected characteristic remnant magnetization and its paleomagnetic pole are overlapping with those of synchronous Eurasia in the 95% confidence range, which supports that it is reliable to apply viscous remnant magnetization in core orientation. The result of fracture orientation in volcanic rocks shows that there are four main groups of fracture in volcanic rocks with their trending in northeast, northwest, nearly north-south and nearly east-west. The former two groups are dominant. Orientation results resolved by the paleomagnetic method are confirmed by borehole image logging.