摘要:The present Carpathian valley network is the result of a long and complex process synchronous to the evolution of the Carpathian orographic system during the Cretaceous – Quaternary period. Among other issues, this study focuses on the genesis of the great defiles shaped by the rivers that cut across (partially or totally) the mountains (the Danube, Olt, Jiu, Prahova, Crişul Repede, Bistriţa, Trotuş, Buzău, Mureş, Someş, etc.), also explaining lowerorder valleys, of limited length (the Bistricioara, Ilva, Tazlău, Teleajen, Cuejd, Strei, etc.). The specialist literature contains a diversity of opinions on two evolutionary concepts – antecedence and stream piracy, but the conclusions have not always been accepted. In establishing the formation stages of different generations of Carpathian valley systems, some general conditions have been taken into consideration (formation of the mountain system by tectonic movements; the evolution of marginal base levels, significantly influencing the intensity of linear and headward erosion; the orographic structure – a relatively ring-like mountain system built of groups of massifs and tectonic basins; the evolution of morpho-climatic systems). At the same time, some regional conditions (partial or total transversal corridors, erosion levels and terraces along the valleys, piedmont glacis, etc.) have been taken into account. The analysis of these elements allowed us to highlight two main evolution stages: Miocene – Middle Pontian (preserving the traces of the oldest valleys) and Dacian – Holocene (when many different generations of valleys were formed, preserving the most numerous morphological evidence), revealing the formation by antecedence and superposition of defiles and gorges, of the four generations of the valley system, and their varied local structure determined by tectonics, volcanism, geological patterns and changing role of the base levels.
关键词:landform evolution; stream piracy; antecedence; palaeogeography; superposition; drainage system