A new > 400 ka paleoenvironmental and paleoclimate record from Tenerife Island (Canary Archipelago)

Abstract

Detailed reconstructions of Quaternary paleoclimate and paleoenviromental evolution of the Canary Islands have been hampered by the scarcity of long terrestrial records. In this study, we present the results of a multiproxy approach based on sedimentological, geochemical, and magnetic susceptibility measurements in a > 40 m long new sediment cores retrieved from a paleolake located within the Vega Lagunera valley on La Laguna, Tenerife Island (Canary Archipelago). Vega Lagunera is a NE-SW oriented valley formed by fluvial erosion of the Miocene basalts of the Anaga massif and blocked by Late Pliocene and Pleistocene lavas emitted from the NE Dorsal Ridge. The 40 m long sequence represents the longest Quaternary terrestrial record in the Canary Islands. Preliminary sedimentation rates based on OSL dates in previous cores suggest a basal date of > 400 ka and a 9 m long Holocene record. The geochemical and magnetic susceptibility signatures identified a shallow lake with clastic alluvial influences during the Pleistocene, a rapid Holocene onset and dominant shallow lacustrine sedimentation since mid Holocene till drainage of the remnant lake in mid 19th century. The interplay of alluvial and lacustrine facies throughout the Holocene period and the geochemical evolution characterized the sedimentological processes linking lake and catchment dynamics, organic productivity, nutrient supply, and runoff. Age models are in progress to identify the glacial / interglacial evolution of these oceanic islands and the relative role of subtropical and mid latitude atmospheric and oceanic patterns.