汾河流域地貌发育对构造运动和气候变化的响应

自中更新世中晚期以来，由于构造运动及气候变化，在汾河流域系列盆地中无论是地貌还是沉积都出现了相应的变化。根据对系列盆地中普遍发育的三级冲湖积台地的成因分析，发现发生于0.76MaBP,0.55MaBP及0.13MaBP的3次大幅度区域构造抬升是导致古湖盆湖退，三级台地形成的根源，根据对太原盆地东南边缘的一台地-洪山台地湖积层的分析，发现在相邻两次构造抬升之间的构造相对稳定期，气候变化完全控制着湖盆的演化，由第四纪气候的干湿变化对象太原盆地这样大的湖盆，一般只引起不大于4.5m的湖面升降，与构造抬升引起的湖面变动相差甚大，作为影响河湖地貌发育的2个主导因素，构造运动是主要的，气候变化只是在构造稳定期才突出地显示其影响。

Response of Landform Development to the Tectonic Movement and the Climate Changes in Fenhe Drainage Basin

Based on analysis of the characteristics of the terraces in patterns and sediment ofthe Fenhe drainage basin, we find it was the three tectonic uplifts that caused the formation ofthree-level terraces. These uplifts took place at 0.76 Ma BP, 0.55 Ma BP and 0.l3 Ma BPrespectively and resulted in the three low-level stages of the paleolake in consistent with thedevelopment of S8, S5, S1, in time. Compared with the neotectonic movements in the upperreaches of the Yellow River, the three tectonic uplifts in this region are in correspondence withthem, and this may imply that the neotectonic uplifts of the Qinghai-Tibet Plateau strongycontrolled the tectonic movements in the Fenhe drainage basin. According to the features oflaustrine sediment deposited from the time when S5, ended its formation to the time when S1,began to develop, we also find the changes in paleoclimate from dry to wet influenced thedevelopment of the paleolakes. The lake levels rose when it was wet and dropped when it wasdry, but the extent of this change of the lake levels was no more than 4.5 m, and much smallerthan that caused by tectonic moveme.