Response of the Pedernales River of Central Texas to Late Holocene Climatic Change

Abstract

Abstract Geomorphological investigations of modern fluvial systems are based on the premise that stream channels develop an equilibrium morphology that represents an accommodation to the relationship between the independent variables of discharge and sediment supply. Long-term changes in this relationship, often due to climatic change, result in morphological and sedimentary adjustments by the fluvial system that are commonly recorded in alluvial sedimentary sequences. The Pedernales River is a bedload-dominated stream that drains the eastern margins of the Edwards Plateau in Central Texas. In the upper third of the valley, there is a complex alluvial sequence that offers considerable insight into the long-term evolution of this largely erosional landscape. This paper is concerned with the detailed and temporally well-defined late Holocene record, and provides an example of widespread morphological and sedimentary adjustments to subtle changes in climate. Through much of the late Holocene, from ca. 4500 t...