Formation, infill, and dissection of a latest-Pleistocene landslide-dammed reservoir (Betic Cordillera, Southern Spain): Upstream and downstream geomorphological and sedimentological evidence.

Fernando García García, F. Sánchez Gómez, Vicente Navarro, Sila Pla Pueyo

Research output: Contribution to journalArticlepeer-review


A slope collapse in a narrow, mountainous valley led to the formation of a latest-Pleistocene (14,500 cal.
BP) lake dammed behind this mass-movement deposit in the Betic Cordillera (SE Spain). The lithostructural
conditions of the carbonate bedrock, a warm and more humid period at the end of the last
glaciation (Bølling interstadial), and its location very close to a seismic mountain front provide the ideal
context for the destabilization and failure of bedrock and the subsequent formation of this ephemeral
mountain basin. It was filled in 260 years. Estimated specific sediment yield (SSY) is at least two orders
lower than SSY nowadays in SE Spain. The calculated value of 81 t/km2/y is similar to calculated values
from artificial reservoirs in more humid and temperate drainage areas, such as in Central Europe.
Geomorphological and sedimentological features of the siltation of the landslide-dammed reservoir
have been preserved close to the Betic Cordillera mountain front. The reservoir fill consists of over 30 m
of lacustrine and alluvial deposits. The lake created upstream of the landslide dam was silted by mainly
terrigenous (Gilbert-type delta gravels and turbiditic sands) and mixed terrigenousebioclastic sedimentation
(horizontally laminated carbonate mudstones). After the lake was silted, a meandering river
caused linear erosion over the natural dam and deeply dissected the lacustrine deposits above the
river’s pre-landslide profile. This process has allowed the study of the well-preserved internal structure
of the natural reservoir and identification of the stages in the construction and degradation of a semiclosed
basin. The stages involved in the evolution of the landslide-dammed reservoir may provide
insights into studying the development of other closed or semi-closed basins such as mountain basins
or artificial dams.
Original languageEnglish
Pages (from-to)61-71
Number of pages10
JournalQuaternary International
Issue number1
Publication statusPublished - 2011

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