Quaternary tectonics and the evolution of the riverine plain near Echuca, Victoria
Titel:
Quaternary tectonics and the evolution of the riverine plain near Echuca, Victoria
Auteur:
Bowler, J. M. Harford, L. B.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 13 (1966) nr. 2 pagina's 339-354
Jaar:
1966
Inhoud:
Important Late Quaternary tectonic movements near Echuca initiated drainage diversions and modifications from which a detailed geomorphic sequence is established. In this sequence, the development of faults, lakes, lunettes and stream cycles may be placed in correct order and some inferences made about the conditions that caused them. A series of lakes formed in the down-faulted regions in the north and south of the area studied. Three stages of successively lower strand lines are recognized, each with an associated lunette on the northeastern margin. Near Echuca, two of these periods of lake-lunette formation are separated by a riverine phase during which depositional streams crossed the dry lake floor. After final drying of the lakes by draining or evaporation, two further periods of ancestral stream development are described, separated by a period of marginal sand hill development. A final phase of stream incision corresponds to the present Goulburn and Murray river development. The first depositional event after movements on the Cadell Fault occurred nearly 7,000 years ago, indicating an early Holocene age for the period of tectonic activity. Since then, a complex sequence including prior stream deposition, lake-lunette formation, and ancestral river activity has occurred, some of which were due to climatic changes the exact nature of which are not yet clear.
Tijdschrift beschrijving