The Quaternary deposits in Lanzarote and Fuerteventura (Eastern Canary Islands, Spain): an overview

Abstract

The main Quaternary formations observed in Fuerteventura and Langarote (Canary Islands) are aeolian deposits marine terraces and lavaflows. The sand from of all l dunes derive from marine deposits containing final Miocene and early Pliocene fauna. The successive regression left the marine bioclastic sand esposed to aeolian erosion. The dunes contain interbedded levels of land snail shells and insect brood cells. Part of the dunes were covered by Pliocene lavaflows. A thick calcareous crust developed at their tops. In some areas the sand erodedfrom those ancient formations built new dunes, anew buried by Upper Pleistocene lavaflows. Several layers oflittle-evolved palaeosols are intercalated into the aeolian sediments. The Molluscafauna was radiocarbon (c.42 ha; 28-2 7 ha; 23 Ka; c. 15 and 13.8 ha; 9.8-9 ha) and U/Th dated (c.95 ha; c. 138 ha; c. 183 ha; c. 235 ha and >350 ha). Pleistocene fossiliferous marine terraces correspond to isotopic stage 5e and 1. The stage 5e tenaces are located at + 5m above msl. Their faunal assemblage (Strombus bubonius) indicates water temperatures much higher than at present and was UITh and ESR dated at c. 125 ha. Holocene terraces are located at elevations slightly higher than modem beaches and approximately 1 m lower than the Pleistocene tewaces. The fauna has been radiocarbon dated c. 4 and 2 ha