衡水地区咸水层沉积物粒度及氘氧同位素的古气候指示
Paleoclimate Instruction of Sediment Grain Size and Deuterium Oxygen Isotope in Saline Stratum of Hengshui

衡水地区的咸水层特征一直备受关注.为了探讨咸水层分布区的沉积环境与咸水形成期的古气候特征，利用钻孔(深度130m)采集了衡水地区咸水层沉积物，进行了沉积物粒度和粘性土孔隙水氘氧同位素测试.沉积物粒度标准偏差显示，剖面上由深至浅，沉积时期水动力呈由弱到强再到弱的变化趋势，其中水动力强段为90~65m,为厚层砂砾层.孔隙水TDS和δ18O特征显示在6m以上受到大气降水和人类活动的影响，并且主要是以淡水灌溉影响为主.剖面上粘性土孔隙水的δ18O在130~90m平均值为-11.5‰，65~29m平均值为-12.1‰，23~0m为-10.6‰，而下部淡水含水层地下水δ18O为-9.8‰，上部咸水含水层地下水δ18O为-8.2‰，粘性土孔隙水δ18O明显偏负于含水层的地下水，反映保存记录了古气候信息.130~90m，δ18O先增大后减小反映温度先升高后降低；65~29m,δ18O反映温度偏低的气候特征；23~0m，δ18O相对比较稳定，总体偏正，反映了全新世为一个相对较为稳定但较高的温度.
The characteristics of saline stratum in Hengshui have always been concerned. In order to discuss the paleoenvironment and the paleoclimate in Hengshui area, grain size and pore water stable isotope (δD,δ18O) of clay collected from Hengshui saline stratum(thickness of 130m) by drilling were analyzed. The standard deviation of sediment grain size shows that the hydrodynamic strength changed from weak to strong and then to weak, there is a deep gravel layer in 90-65m, which reflects a strong hydrodynamic strength and a humid clime. The TDS and δ18O reflect the affect of atmospheric precipitation and human irrigation above 6m, specially for the human irrigation. The mean value of δ18O at depth of 130-90m is -11.5‰, and it is -12.1‰ and -10.6‰ at depth of 65-29m and 23-0m. The δ18O of aquifer at 90-65m is -9.8‰, and -8.2‰ of 29-23m. The δ18O of clay pore water is negative compared with the aquifer groundwater, reflecting that the clay pore water saves paleoenvironment information. The δ18O at depth of 65-29m firstly increases and then decreases reflecting the temperature firstly increases and than decreases; the δ18O at depth of 65-29m reflects a low temperature; the δ18O at depth of 23-0m is relatively stable, but is positive overall, indicating a warm climate in Holocene