Holocene coastal palaeoenvironments in Las Canteras beach, Gran Canaria (Canary Islands, Spain)

Abstract

Las Canteras beach outcrops correspond to vestiges of Holocene palaeoenvironments that represent changes in the sea-level and climate conditions. Under detailed stratigraphic, sedimentological, mineralogical, petrographic, geochemical and dating studies it has been possible to identify and characterise a variety of facies from Las Canteras palaeoenvironments. The basal level is a beachrock (several calcarenite layers, dipping 8 to 15 degrees seawards and with isopaque LMC cement around sand grains of marine origin) formed through a rising sea level during the Present Interglacial stage (lower Holocene >6.6 ka). Afterwards, during middle Holocene (about 6.6 ka, 14C dating), coastal progradation phase or lower sea level (or both) could lead land emersion and formation of soil, with well-developed weathering and accumulation horizons and the presence of abundant terrestrial gastropods. Overhead, but only observed in the Central Arc of the beach, eolianite facies from cemented palaeocoastal dunes were identified (calcarenite levels, dipping around 20 degrees landward, and with phreatic LMC and vadose aragonite cement) formed in the upper Holocene (<6.6 ka). This eolian deposit represents the highest coast progradation or the end of low-stand sea level, with a more recent time than the palaeosol, whereas its cementation can be interpreted as the beginning of the sea level rise towards the current highstand sea level situation.