Climate dynamics during the last 3000 years forced environmental and sedimentation changes in southern Spain: The Laguna Grande de Archidona record

A geochemical, mineralogical, and sedimentological analysis of the sedimentary record from Laguna Grande de Archidona (LGA), a lake in southern Spain, produced a high-resolution climate and human activity record for the southwestern Mediterranean over the past three millennia. Lake level changes, organic matter, and gypsum intervals were primarily driven by precipitation and hydrological shifts. From 3300 to 2600 cal yr BP, dry conditions prevailed, particularly from 3050 to 2600 cal yr BP, coinciding with a regional drought tied to a positive North Atlantic Oscillation (NAO). The wettest period, from 2600 to 1400 cal yr BP during the Iberian Roman Humid Period (IRHP), was marked by increased groundwater and lake stratification due to negative NAO, which generated the precipitation of gypsum and manganese oxides. However, this relatively wetter period was interrupted by two arid events between 2300–2200 and 2150–2050 cal yr BP. A dry phase spanned the Dark Ages through the Medieval Climate Anomaly (MCA; 1400–700 cal yr BP), while the Little Ice Age (LIA) showed varied but generally wetter conditions, followed by an arid period from ∼1600–1850 CE. The Industrial Epoch (1850–1957 CE) also saw dryness, with late 20th-century changes attributed to modern climate impacts and irrigation practices.