论文部分内容阅读
昆特依盐湖是柴达木盆地盐湖演化和古气候研究的重要对象。前人对昆特依盐湖钻孔的年代学和地球化学组成特征开展过一些研究,但由于采样间距大,限制了对成盐演化过程的深入理解。目前关于昆特依盐湖磁化率特征的研究尚未见报道。对昆特依盐湖ZK1402钻孔(35 m深)的14C年代和磁化率进行了初步研究。结果表明:1)钻孔由含盐碎屑层和盐层的互层所组成。盐层的低频磁化率值低,含盐碎屑层的低频磁化率值高。低频磁化率清晰地记录到古盐湖经历了4次显著的成盐期。钻孔的低频磁化率和高频磁化率的变化极为相似。2)低频磁化率和频率磁化率(百分比形式)呈负相关关系。3)钻孔9.6 m深处的加速器质谱(AMS)14C校正年代为23 333±255 cal a BP,24.8 m深处的年代为31 780±442 cal a BP,33.0 m深处的年代(19 259±207 cal a BP)出现倒转。钻孔24.8 m和33.0 m深处的14C年龄可能被低估。
Kuanti Salt Lake is an important target for the study of the evolution and paleoclimate of the salt lake in the Qaidam Basin. Some previous studies on the chronology and geochemical composition of the Quetzal-based salt boreholes have limited the understanding of the evolution of salt formation due to the large sampling distances. At present, there is no report about the magnetic susceptibility characteristics of Quetzal-lakeshore. The 14C age and magnetic susceptibility of the Quetzal-based salt lake ZK1402 borehole (35 m deep) were studied. The results show that: 1) The borehole consists of an interbedded layer of salt-bearing detritus and salt. The low frequency magnetic susceptibility of salt layer is low and the low frequency magnetic susceptibility of salt-bearing clastic layer is high. Low-frequency magnetic susceptibility clearly recorded that the ancient salt lake experienced four significant salinization periods. The variation of low frequency magnetic susceptibility and high frequency magnetic susceptibility of the borehole is very similar. 2) There is a negative correlation between low frequency magnetic susceptibility and frequency magnetic susceptibility (percentage form). 3) Drill the accelerator MS at 9.6 m depth (AMS) The 14C correction was 23 333 ± 255 cal a BP, with a depth of 24.8 m at 31 780 ± 442 cal a BP, an age at 33.0 m (19 259 ± 207 cal a BP). The 14C ages at 24.8 m and 33.0 m for drilling holes may be underestimated.