冀北崇礼—赤城大断裂的多相逆冲——兼论内蒙地轴隆升的构造制约因素

阐述了内蒙地轴南缘崇礼—赤城东西向大断裂的多变形变质相构造岩带特征,确定并阐明了五台—吕梁期的角闪岩相韧性逆冲、海西晚期的绿片岩相脆—韧性逆冲及燕山早期的表层次脆性逆冲的多次逆冲运动。根据各期构造岩的变质温压条件,对北盘内蒙地轴在几次逆冲期的抬升幅度进行了分析,提出内蒙地轴是水平挤压体制控制下的隆起带。

MULTIPHASE THRUSTING OF THE CHONGLI - CHICHENG REGIONAL FRACTURE OF NORTH HEBEI PROVINCE AND TECTONIC FACTORS OF INNER MONGOLIAN AXIS UPWARPING

The Chongli-Chicheng regional fracture , which is located at the south margin of Inner Mongolian axis , is a E -W trend complex tectonite-magmatite zone . It suffered the thrusting movements in four periods , i. e. later Wutai period , later Luliang period , later Variscan period and early Yanshanian period . Their thrusting directions all are towards south from north . Wutai period shows amphibolite fades ductile thrusting , and so does Luliang period which makes Inner Mongolian axis upwarping rough twelve kilometers . Later Variscan period thrusting is greenschist fades brittle-ductile deformation and makes Inner Mongolian axis upwarping rough two kilometers . Early Yanshanian period shows brittle low -angle thrusting . Inner Mongolian axis is a upwarping belt which is controlled by horizontal compressional movements .