Quaternary to recent drainage evolution of the Rambla de Lucainena, SE Spain

The study is focused on the small drainage catchment of the Rambla de Lucainena, situated between the Carboneras and Sorbas basins of the Almeria Province in SE Spain. Previous research has shown that this river has developed due to aggressive headcutting during the Plio/Pleistocene, which has been strongly influenced by the unique climate and active tectonics of this semi-arid area. Fluvial incision during the Quaternary has left a series of terrace fragments from which four important terrace groups have been identified. This study has taken a unique approach by integrating the analysis of contemporary process data and incorporating it into the interpretations of the Quaternary landforms. This approach has emphasised the differences between fluvial processes in semi-arid areas and temperate regions, a factor which is frequently ignored in reconstructing drainage within semi-arid fluvial studies. This is one of the first studies of drainage reconstruction to adopt this approach and it is hoped that it will highlight the need for the integration of contemporary and past data to develop a fuller understanding of fluvial history. Of the four terrace levels identified here, two are of particular palaeoenvironmental importance. The oldest of these episodes is documented by the presence of fractured clast pairs within one of these terrace levels, interpreted as the product of frost weathering. This implies a period of periglacial conditions during the Quaternary. The second event of significance is recorded by a 20 m thick deposit of aggradational fines which indicates a period of increased precipitation and a much wetter climate regime. These observations conflict with the simple view of Quaternary palaeoclimate, that of increasing aridity during glacial periods which is widely followed in the Quaternary literature on SE Spain. The observations here suggest, as one might expect, that the palaeoclimatic record is more complex and requires further investigation. Of particular importance is establishing some form of dating control for these events, the absence of which generally limits the wider significance of the observations reported here. This work, however, demonstrates for the first time the palaeoclimatic significance of the Quaternary sediments and landforms of SE Spain, an aspect which has frequently been neglected, since they are commonly used to interpret the tectonic evolution of the area.

Level dc:type.qualificationlevel

mphil

Grantor dc:publisher.institution

University of Greenwich

Year dc:date.issued

1997

Author dc:creator

• Rosso, Joanne Louise

Advisors dc:contributor.advisor

• Bennett, Matthew
• Doyle, Peter

• QE Geology

Language dc:language

en