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为探究微观磁组构特征与宏观沉积构造、长形生物化石特点等指标在恢复古水流向问题上的关联性,对塔里木盆地塔南地区的257块古地磁定向样品进行了磁组构特征研究。发现全剖面样品的磁化率最大轴赤平投影为南北方向,由于旱地冲积扇水动力较强,导致流水动力方向与磁化率最大轴方向垂直,指示古水流方向为东西向;而化石层围岩样品的磁化率主轴主要集中在90°方向,鉴于化石集中埋藏地区水动力急剧转弱,磁化率最大轴方向与古流向一致,这与长形骨骼展布方位的统计结果 70°~115°相吻合,均显示自东向西,微观磁组构与宏观长形骨骼展布所指示的方向相一致。证实了在宏观条件不可见时,对沉积物进行大样品数量的磁组构分析可以便捷地承担该地区的沉积动力学辨识工作,并为进一步拓展化石埋藏学统计研究提供了可靠的依据和手段。
In order to explore the correlation between micro-magnetic fabric features and macro-sedimentary structures and characteristics of long-shaped biological fossils in restoring ancient water flow, the magnetic fabrications of 257 paleomagnetic samples in Tanan area of Tarim Basin were studied . It is found that the maximum axial azimuth projection of the whole-sectioned sample is north-south direction. Because of the strong hydrodynamic force of the alluvial fan in the dryland, the hydrodynamic direction is perpendicular to the direction of the maximum axis of magnetic susceptibility, indicating that the paleocurrent direction is east-west; The major axis of the magnetic susceptibility is mainly in the direction of 90 °. In view of the sharp weakening of hydrodynamic force in the area where the fossils are buried, the direction of the maximum magnetic susceptibility coincides with that of the paleocurrent, which agrees with the statistic result of the longitude skeleton distribution orientation of 70 ° ~ 115 ° , Are shown from east to west, the micro-magnetic structure consistent with the direction of macro-long skeletal distribution. It is confirmed that when the macroscopic conditions are not visible, the magnetic structure analysis of large sample quantities of sediments can easily undertake the sedimentation kinetic identification of the area and provide a reliable basis and means for further expanding the statistical study of fossil burial. .