摘要:
大兴安岭火山岩带北段呼中火山岩区,在中-晚侏罗世时期,最大主压应力轴方向为NW266°~316°,早白垩世最大主压应力轴为NE12°~50°,显示侏罗纪与白垩纪应力场的应力状态是截然不同的,但都处于拉张环境下。中-晚侏罗世由于NNE-SSW向的拉伸应力场的作用,在本区北部发生构造岩浆活动,形成了上黑龙江断陷盆地如NWW向展布的劲涛-蒙克山中基性火山喷发带,派生的NEE向张扭性应力使前中生代基底构造重新活动,形成大面积火山喷发。而早白垩世在NE-SW向拉伸应力场作用下,"额尔古纳地块"东部形成拗陷带,火山基底构造为NE-NNE向。
Abstract:
In the volcanic rock area of Huzzhong in the northern part of Dahiinganling volcanic Zone, the maximum principal compressive strress of Middle-Late Juraassic were mainly oriented the direction of NW266°~316°;but one of Early Cretaceous of the direction NE12°~50°.It shows that Mesozoic stress fields were different in Jurassic and Cretaceous, but these fields are all in tensile environment. In Middle-Late Jurassic, the tectonic magma activity resulting from NNE-SSW tensile stress field in the northern part of this area formed upper Heilongjiang fault basin and NWW trending Jintao-Mengkeshan intermediate-basic volcanic belt, its induced NEE trending tenso-shear stress field made the Premesozoic basement tectonics rejuvenate and formed volcanic eruption of big area. But under the control of NE-SW tensile stress field of Early Cretaceous, in the eastern part of "Ergun Block" sag belt was formed and the basement tectonics is NE-NNE direction.
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