Travertine deposited around the Niangziguan karst springs was used as a new type of paleoclimate record in this study. Five stages of climate change in northern China from 200± ka to 36± ka before the presen...Travertine deposited around the Niangziguan karst springs was used as a new type of paleoclimate record in this study. Five stages of climate change in northern China from 200± ka to 36± ka before the present (B. P.) were reconstructed using the 18O and 13C isotope record of the travertine. Tendency of the change was towards a more arid climate. Coupling the temporal-spatial evolution of the springs with climate change, the hydrogeological evolution could be divided into four major periods since middle Pleistocene: (1)No spring period; (2)The initial period of spring outcropping as the predominant way of discharge; (3)The culmination period of spring development; and (4)The spring discharge attenuation period. The attenuation is partly related to the decrease of recharge as a result of the dry climate after 90±kaBP.展开更多
基金The research work was financially supported by the National Natural Science Foundation of China (Grant No. 49832005) the Ministry of Science and Technology of China (95-pre-39).
文摘Travertine deposited around the Niangziguan karst springs was used as a new type of paleoclimate record in this study. Five stages of climate change in northern China from 200± ka to 36± ka before the present (B. P.) were reconstructed using the 18O and 13C isotope record of the travertine. Tendency of the change was towards a more arid climate. Coupling the temporal-spatial evolution of the springs with climate change, the hydrogeological evolution could be divided into four major periods since middle Pleistocene: (1)No spring period; (2)The initial period of spring outcropping as the predominant way of discharge; (3)The culmination period of spring development; and (4)The spring discharge attenuation period. The attenuation is partly related to the decrease of recharge as a result of the dry climate after 90±kaBP.