Holocene climate variability based on two lacustrine sediment sequences from Cádiz, southern Spain

• Main Author: Hoff, Jasmijn van ´t
• Format: Doctoral or Postdoctoral Thesis
• Language: German; English
• Published: 2017
• Subjects: ddc:550; Medina; North Atlantic
• Online Access: https://kups.ub.uni-koeln.de/8120/; https://kups.ub.uni-koeln.de/8120/1/Dissertation_Jasmijn.pdf

Iberia, and especially southern Spain, has been the focus of only limited palaeoclimatological research. The scarcity of palaeoclimate archives has led to an interpolation of archives from distant sites. The palaeoclimate reconstruction of southern Spain is therefore mainly based on the interpolation of marine records from the Alboran Sea, the Gulf of Cádiz and the North Atlantic Ocean. The understanding of the impact and effects of Holocene changes is relatively poor. The execution of palaeoclimatological research in southern Spain has been hampered by the lack of suitable sites. This thesis contributes to the understanding of the Holocene climate change in southern Spain with two new cores drilled in shallow saline lakes. The arid southern Spain is a region without deep natural lakes, these ´salinas´ represent a promising alternative for palaeoclimate research. In this thesis, the methods and results of sedimentary and palaeoclimatological analyses of the modern lake sediment and soil catchment samples of Laguna de Medina, and the sediment sequences of Laguna de Medina and Laguna Salada are presented. The methods include XRF scanning, MSCL logging, particle-size analysis, total (in)organic carbonate analysis, determination of total sulphur, and total nitrogen, and XRD analysis, reinforced with the statistical method principal component analysis. The results are used to characterize the sediments and to interpret the changing climatological and environmental settings during the Holocene. The modern sediments of Laguna de Medina were studied with the same methods, to obtain a modern analogue for the long record. The primary objective of this thesis was to disentangle the Holocene climate of southern Spain, based on the lacustrine archives Laguna de Medina and Laguna Salada using 25.65 and 12 m long cores, respectively. Shifts in sedimentary deposition and geochemical proxies identify that southern Spain is highly vulnerable and responsive to climate change. Sedimentological, geochemical, mineralogical and ...