黄河中游河流阶地的形成与水系演化

本文据黄河中游各流域大量地质地貌实测资料，以连通各河流全线的各级阶地中,沉积物与古土壤的层位关系为主线，用年代学和古土壤断代法确定了阶地年代，阐述了四期九亚期水系演化史，并指出黄河中游及其主要支流诞生于更新世早中期167－145万年之间，之后发育了六级阶地和两级河漫滩。

THE FORMATION OF RIVER TERRACES AND EVOLUTIONOF DRAINAGE SYSTEM IN THE MIDDLE YELLOW RIVER

: In the past many scientists had, from distinct data, estimated the birthday of the Yellow River at the Pliocene, the Early Pleistocene, the Middle Pleistocene, or the Late Pleistocene. In this article the author is the first to propose a new position: the Yellow River and its main tributaries were formed in 1670-1450 ka B. P., i.e. early-middle Pleistocene, and after that 6 terraces and 2 valley flays have developed. The ages (ka B. P.) are as follows: TG, 1670--850, T5, 850-470, T4, 470-100, T3,100-10, T2, 10-0.7, T1, 0.7-0.3, high valley flay 0.3-0.15, lower valley flay 0.15-0. The periods of hydrographic evolution may be di- vided into 4 main stages and 9 substages since the Pliocene. These new conclusions are obtairied on the basis of a host of field investigations along the Yellow River and its tributaries, and according to the principle of "paleosol-dating method" suggested by the author.