中文摘要：

为了探讨海南岛东北部侏罗纪以来水平主压应力的方向及其演化,对海南岛东北部二叠纪与侏罗纪花岗岩中大量节理的产状进行了野外实测与室内计算分析.节理特征表明,研究区二叠纪与侏罗纪花岗岩均有三组共轭剪节理.这三组共轭剪节理的错动关系及室内计算分析表明,研究区的水平主压应力方向由北北东—南南西（35.8°～215.8°）,依次演化为南南东—北北西（143.1°～323.1°）、南东东—北西西（94.4°～ 274.4°）.区域构造活动期、岩浆作用期、成矿期的对比研究结合节理所在花岗岩的时代、所处的空间位置表明,侏罗纪以来太平洋板块运动事件对本区产生的挤压作用,较好的解释了研究区侏罗纪以来的水平主压应力方向及其演化.南东东—北西西（94.4°～274.4°）的水平主压应力方向及其在本区最为发育,可能是喜山期哀牢山-红河韧性剪切带大规模左行走滑从而产生南东东—北西西向的水平主压应力.之后的板块运动亦可能对研究区的应力场产生影响.

英文摘要：

In order to reveal the evolution of horizontaI principal compressive stresses in the northeastern Hainan Island of China,this paper conducts a survey on joints and fractures developed in the Permian and Jurassic granites.The character of joints,shows there are three groups of conjugate joints in the granites.The dislocation and calculation of above three groups of conjugate joints,indicate that the horizontal principal compressive stress in the northeastern Hainan island had undergone direction from NNE-SSW（35.8° ～215.8°）,through SSE-NNW （143.1 ° ～ 323.1 °）,and finally to SEE-NWW （94.4° ～274.4°）.A comparative study on magmatic activities,structural events and mineralizations,with conferring to the period and place of granites in which the joints occurred,we put forward that the compressive force of the Pacific plate motion can explain the direction and evolution of the horizontal principal compressive stresses in the study area since the Jurassic.The principal horizontal compressive stresses of SEE-NWW（94.4° ～274.4°） and its dominance in the study area may derive from the long-range effects of the left-lateral strike-slip of the Ailao Shan-Red River metamorphic belt in the Himalaya orogeny.The movement of plates after that may also have affected the stress field of the study area.