胶东招远—平度断裂活动性质及活动时代

Active properties and age of Zhaoyuan-Pingdu fracture zone

胶东地区的招远—平度断裂是一条重要的控矿断裂,经过了多阶段的演化历史。前粉子山期,招平断裂以韧性剪切为主,燕山期招平断裂主要以脆性变形为主,这样形成了韧性变形、脆性变形在同一空间的叠加。招平断裂至少经历了3次以上的活动,相对运动规律是:左旋—右旋—左旋,力学性质则呈现出扭性—扭张性—扭性—压扭性的变化。招平断裂构造片岩的40 Ar/39Ar坪年龄为(134.26±0.34)Ma,40 Ar/36Ar—39Ar/36Ar等时线年龄为(134.50±1.46)Ma。

Zhaoyuan-Pingdu fracture zone in Jiaodong district is one of the most important ore control fracture belts, belonging to Tan-Lu fracture system. Its formation experienced a long evolutional history. Priority to Fenzishan stage, Zhaoyuan-Pingdu fracture zone showed a ductile deformation, with the upgrowth mylonitized belt formed and uplift of Jiaodong geoblack followed. In Yenshan stage, Zhaoyuan-Pingdu fracture zone rejuvenated under the effect of the Mesozoic stress field, and brittle deformation took place as a principal event, thus brittle and ductile deformations were superimposited in the same space.From south to north, the morphotropism ranged from ductile into brittle deformation, companied with the intensive thermal event. At least three times the relative movement took place in Zhaoyuan-Pingdu fracture zone, and the directions changed as follows: left lateral slip, right lateral slip, and then left lateral slip, and the mechanical properties: torsion, torsion tension torsion, and compresso shear. The 40 ?Ar/ 39 Ar isotope dating of muscovite from tectonic schist is(134.26±0.34)Ma, and the isochron of 40 ?Ar/ 36 Ar 39 Ar / 36 Ar (134.50±1.46)Ma.