Aeolian influx and related environmental conditions on Gran Canaria during the early Pleistocene

Abstract

The island of Gran Canaria is regularly affected by dust falls due to its proximity to the Saharan desert. Climatic oscillations may affect the Saharan dust input to the island. Geochemical, mineralogical, and textural analysis was performed on a well-developed and representative early Pleistocene paleosol to examine Saharan dust contribution to Gran Canaria. Significant and variable Saharan dust content was identified in addition to weathering products such as iron oxides and clay minerals. Variations in quartz and iron oxide concentrations in the paleosol likely reflect different Saharan dust input in more/less-contrasted rhexistasic/biostatic climatic conditions. Linking the quartz content in Canarian soils, the Ingenio paleosol, and two Canarian loess-like deposits to different ages from the Quaternary, we hypothesized that the dust input should be lower (about 33–38%) throughout the early to middle Pleistocene than during the late Quaternary. The Saharan dust input to the Gran Canaria profile in the Pleistocene persisted in spite of climatic variations.

The antiquity of the Sahara Desert: New evidence from the mineralogy and geochemistry of Pliocene paleosols on the Canary Islands, Spain

“…These investigators also note times of increased aridification, based on higher dust flux, at 4.3 Ma, 4.0 Ma, 3.6 Ma, 2.1 Ma, and 0.8 Ma. The data from paleosols in our study and that of Menéndez et al (2019) indicate several periods of African dust delivery to the Canary Islands between~4.8 and 2.8 Ma,~3.0-2.9 Ma, 2.3-1.46 Ma, and at~0.4 Ma. Thus, the Canary Islands record at least 9 periods of paleosol formation, characterized by dust inputs from Africa, between~4.8 Ma and~0.4 Ma, consistent with the ODP Site 659 record.…”

“…Nevertheless, given its proximity to the Canary Islands, Africa is the simplest choice for the source of such sediments. This interpretation is supported by the abundant evidence for African dust inputs to Canarian soils and paleosols during the Holocene and Pleistocene (Muhs et al, 2010;Huerta et al, 2015;Menéndez et al, 2019;Roettig et al, 2019).…”

“…1a). African dust is reported as a component of modern soils on the Canary Islands (Muhs et al, 2010) and is also found in paleosols of Pleistocene age (Huerta et al, 2015;Muhs et al, 2016;Menéndez et al, 2019;Roettig et al, 2019). These studies have demonstrated the presence of an African dust component by identification of minerals exotic to the Canary Islands.…”

“…The volcanic flows (and by inclusion, the intercalated paleosol) at El Mármol on Gran Canaria are dated to between 3.0 Ma and 2.9 Ma (Guillou et al, 2004b) and the section at Punta de Arucas is dated tõ 0.4 Ma (Meco et al, 2002). Menéndez et al (2019) recently studied a paleosol that formed between~2.3 Ma and~1.46 Ma near Ingenio on Gran Canaria (Fig. 3) and also documented an African dust component.…”

Long-term African dust delivery to the eastern Atlantic Ocean from the Sahara and Sahel regions: Evidence from Quaternary paleosols on the Canary Islands, Spain

“…Another issue is the considerable debate about the most important sources of dust in Africa. Many workers have simply ascribed dust inputs in Canarian soils and paleosols to sources in the "Sahara" without much more specificity (Damnati et al, 1996;Williamson et al, 2004;Von Suchodoletz et al, 2008, 2009a, 2009bMenéndez et al, 2009Menéndez et al, , 2019Criado et al, 2012;Faust et al, 2015;Varga and Roettig, 2018;Roettig et al, 2019). This is consistent with a number of studies that have emphasized the importance of the year-round trade wind dust pathway from northwestern Africa, described above (Coudé-Gaussen et al, 1987;Grousset et al, 1992Grousset et al, , 1998Rognon et al, 1996), implying northern, Saharan-derived sources.…”