干旱区湖滨沉积物中不同粒度石英矿物等效剂量对比

The equivalent dose comparison of different grain size quartz from lakeshore sediments in the arid region

采用双单片再生法在4个湖滨沉积物中测量了不同粒径石英的等效剂量值。实验结果出现两种不同情况,一种是在63–400μm粒度区间,石英的De值基本一致,并随粒度增加略微减小;另一种是在125–300μm粒度区间,石英的De值比较接近,而63–90μm、甚至90–125μm石英的De明显偏小约50%。第一种现象与文献[18]的报道是一致的,后一种现象难以用已有的研究成果进行解释。

To investigate the feasibility of OSL dating of lakeshore sediments, equivalent dose （De） values of quartz fractions in different grain-size were measured using the ＂Double-SAR＂ protocol of optical dating in four lakeshore sediments. There are two obvious different relations between De values and grain sizes. The first situation is that the De values are accordant with eath other for fractions between 63um and 400um with a slightly decreasing tread ofDe values as increasing of grain-size. The second situation is that the De values are accordant to each other for fractions between 125um and 300um, while the De values of the 63-90um and even the 90-125um fraction are obviously smaller than others. The first is consistent with those reported elsewhere, while the second can＇t be understood by the previous theory.