Aeolian construction and alluvial dismantling of a fault‐bounded intracontinental aeolian dune field (Teruel Basin, Spain); a continental perspective on Late Pliocene climate change and variability

Abstract

An aeolian dune field migrating to the east encroached on the toes of alluvial fans in the Teruel Basin (eastern Spain) during a short interval in the Late Pliocene (ca 2·9 to 2·6 Ma), when Northern Hemisphere glaciation and strong glacial–interglacial cycles began. Preservation of the dune field was controlled by syn‐sedimentary activity of a normal fault. Ephemeral water discharge eroded aeolian sands and formed V‐shaped channels in which aeolian sandstone blocks accumulated. The incorporation of loose aeolian sand in wadi waters modified the sediment/water ratio, changing the physical properties of the flows as they penetrated the aeolian dune field. The erosion and cover of aeolian dune foresets by sheetflood deposits suggest that dune‐damming caused the intermittent ponding of water behind the dunes and its flashy release. The arid climate in the Late Pliocene western Mediterranean realm favoured the transport of windblown sediments from northern Africa and western Mediterranean land masses into the Mediterranean. The formation of the studied aeolian dune field (2·9 to 2·6 Ma) and possibly others (for example, the Atacama, Namib and Sahara deserts) correlates with a strong increase of the influence of obliquity, which can be attributed to the combination of a regional expression related to the reduced effect of precession due to a minimum in the long‐period (2·3 Ma) eccentricity cycle and a remote expression of the onset of the Northern Hemisphere glaciation.

Climatic versus halokinetic control on sedimentation in a dryland fluvial succession

“…A possible variation on this mechanism for the generation of these elements could have arisen where locally active fluvial systems encroached onto the flanks of a pre‐existing topographic high, resulting in localized erosion, entrainment, transport and deposition through incision (c.f. Rodríguez‐López et al ., ), and collapse at the outer bank of the channel (Gomez‐Gras & Alonso‐Zarza, ). In places, F3 elements can be shown to be associated with locations proximal to topographic features on the alluvial plain, including topography generated by salt‐wall uplift (discussed later).…”

Archean to Recent aeolian sand systems and their sedimentary record: Current understanding and future prospects

“…In central Spain, the Middle to Upper Pliocene Escorihuela Formation records the accumulation and preservation of an aeolian dunefield related to synsedimentary activity of normal faults in a syn‐rift environment. This system is dominated by the interaction between constructive and destructive episodes related to high‐frequency climatic changes (Rodríguez‐López et al ., ). Accumulation during the Middle to Upper Pliocene is also recorded in the northern Apennines of Italy (Fig.…”