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综合近期垂直形变、部分地区水平形变以及跨断裂的测量资料,说明北京及其晋冀交界地区区域应力场以北西—北北西为主张应力和北东—北东东为主压应力方向,并有深部构造的上拱作用,在几种力的联合作用下,燕山折断带山区继续抬升,断陷盆地和北京平原相对下降,区内大部分北东向断裂表现为张扭性,北西向具有反扭特征。短基线资料表明近期水平形变大于垂直形变,张应变大于压应变。上述地区大致位于北纬39°40′—40°50′、东经176°50′—113°10′,包括北京及其西北部分的一系列盆地,直至晋冀交界地区。这个地区从1969年以来,被有些单位列为可能发生强震的危险区,其中地壳形变手段即是划分该危险区的依据之一。
Based on the recent vertical deformation, horizontal deformation in some areas and measurement data of cross-fault, it is shown that the regional stress field at the junction of Beijing and its Jin-Ji area is dominated by Northwest-North-North-West stress and North-East-East-East pressure. Under the combined action of several forces, the Yanshan uplift belt continues to rise up, and the fault basins and the Beijing Plain decline relatively. Most of the northeastern faults in the region show torsional shear and the northwest direction has anti Twisted features. Short baseline data show that the recent horizontal deformation is greater than the vertical deformation, tensile strain greater than the compressive strain. These areas are generally located at 39 ° 40’-40 ° 50 ’north latitude and 176 ° 50’-113 ° 10 ° east longitude, including a series of basins in Beijing and its northwestern part up to the junction of the Jin-Ji area. Since 1969, this area has been classified by some units as a danger zone where strong earthquakes may occur. Among them, crustal deformation means is the basis for the division of the danger zone.