Climate and Human impact synergies in Mediterranean Mountains: The - PowerPoint PPT Presentation

Climate and Human impact synergies in Mediterranean Mountains: The Late Holocene records of the Iberian Range karstic lakes (NE Spain) F. Barreiro-Lostres * Pyrenean Institute of Ecology-CSIC, Spain A. Moreno Pyrenean Institute of Ecology-CSIC, Spain S. Giralt Earth Sciences Jaume Almera Institute-CSIC, Spain P. Mata Spanish Geological Survey (IGME), Spain B. Valero-Garcés Pyrenean Institute of Ecology, CSIC, Spain * ferbalos@ipe.csic.es

Introduction Climatic variability on the Iberian Peninsula  In the context of the IP, the IRHP, the MCA and the LIA are the main Holocene rapid environmental changes during the last millennnia and they had a strong impact on the hydrological cycle  These oscillations specially control the water availability in Mediterranean areas. Instituto Pirenaico de Ecología (IPE) CSIC

Introduction  The IRHP (2600-1600 yr BP) is the most humid period in the last 3500 yr (Zoñar lake).  The MCA (IX- XV centuries) has been detected as a relatively arid period (Estanya, Zoñar lakes).  The LIA (1300-1850 yr AD) is characterized by a significant increase in aquifer recharge, indicated by several records from karstic lakes (La Cruz, Taravilla and Zoñar lakes). Instituto Pirenaico de Ecología (IPE) CSIC

Introduction  during these periods seems to be significant latitudinal variability...  we need to integrate studies from different areas (lakes) at different latitudes Instituto Pirenaico de Ecología (IPE) CSIC

We are studying several lakes on the Iberian Range, at the East of the IP. Introduction Location and Geological settings 1) Taravilla 2) El Tobar 3) La Parra 4) El Tejo, La Cruz Instituto Pirenaico de Ecología (IPE) CSIC

On the Iberian Range Introduction Location and  Large carbonate areas afected by endo- Geological and exokarstic processes develop settings … travertine-damned lakes … circular funnel-shaped depressions  If these depressions intercept the regional aquifer, relative deep lakes occur. Instituto Pirenaico de Ecología (IPE) CSIC KARST LAKE SEDIMENTS IMPERMEABLE

Introduction Location and  These systems are very sensitive to Geological settings regional hydrological balances.  In response to climatic changes, they present large variations on water properties (water table levels, chemistry, biota, etc.)  So, climatic, environmental changes and the possible human impact are recorded in the sediments Instituto Pirenaico de Ecología (IPE) CSIC

La Parra lake Introduction  Doline Location and system near Geological Cuenca settings La Parra  1000 m asl.  1 ha area  17 m depth  Holomictic Inputs: Mainly groundwater and runoff water.  Outputs: Irrigation wells Instituto Pirenaico de Ecología (IPE) CSIC  500 mm av. precipitation

La Parra lake Introduction Location and Geological settings La Parra Instituto Pirenaico de Ecología (IPE) CSIC

La Parra lake Introduction 11 sedimentary facies (3 main Units) Location and Geological settings A) Detrital B) Laminated La Parra 1) Silts Facies A Facies B Facies C Facies D Facies E 2) Sands 3) Gravels Instituto Pirenaico de Ecología (IPE) CSIC Facies F Facies G Facies H Facies I Facies J

 Unit III: 1 st lacustrine deposits → Increase of water table Introduction - Laminated facies changing Location and to coarser silts: Geological settings - Rapid water table levels changes; La Parra - Littoral and shallower environment deposit . Instituto Pirenaico de Ecología (IPE) CSIC

Unit II: Detrital fine facies Introduction  Increase of fine siliciclastic Location and inputs Geological settings  Implies: La Parra - Higher lake levels - Higher local anthropogenic impacts (erosion). Instituto Pirenaico de Ecología (IPE) CSIC

Bottom Unit I: Coarser facies deposition Introduction  Coarser facies at the Location and center of the lake: Geological settings  Implies shallower levels and an increase on La Parra proximal detrital inputs 1 1 Instituto Pirenaico de Ecología (IPE) CSIC

Medium Unit I: Fine and Laminated facies Introduction  Higher lake levels. Location and Geological  Laminated facies: as settings trends to anoxia at lake bottom La Parra (similar pattern than nearby La Cruz lake) 2 2 Instituto Pirenaico de Ecología (IPE) CSIC

Top Unit I: Dominancy of fine massive silts Introduction  Laminated facies Location and disappear Geological settings 3 3  Relative drop of lake levels during recent times La Parra Instituto Pirenaico de Ecología (IPE) CSIC

Age Model Introduction Location and Geological settings La Parra Instituto Pirenaico de Ecología (IPE) CSIC

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 1 . 6 4 Sr/Ti 1 . 2 0 . 8 0 5 0 0 0 0 0 0 0 . 4 0 Ca 2 5 0 0 0 0 0 1 0 0 0 0 Mn 0 5 0 0 0 4 0 0 0 0 0 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 Several geochemical proxies used to reconstruct the history of the lake. (Detrital inputs, Organic productivity, REDOX stages)

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 1 . 6 4 Sr/Ti 1 . 2 0 . 8 0 5 0 0 0 0 0 0 0 . 4 0 Ca 2 5 0 0 0 0 0 1 0 0 0 0 Mn 0 5 0 0 0 4 0 0 0 0 0 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 During the late IRHP (300-500 AD), occurs the onset of lacustrine sedimentation, with a rapid change on detrital input (Ti, Si fast rise & drop of water table around 425 AD)

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 1 . 6 4 Sr/Ti 1 . 2 0 . 8 0 5 0 0 0 0 0 0 0 . 4 0 Ca 2 5 0 0 0 0 0 1 0 0 0 0 Mn 0 5 0 0 0 4 0 0 0 0 0 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 The DA (550-900 AD) start with high clastic inputs (Ti, Si) towards the lake and coarser facies occurs (lower lake levels), that change to fine facies (higher lake levels)

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 1 . 6 4 Sr/Ti 1 . 2 0 . 8 0 5 0 0 0 0 0 0 0 . 4 0 Ca 2 5 0 0 0 0 0 1 0 0 0 0 Mn 0 5 0 0 0 4 0 0 0 0 0 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 - During the onset of the MCA (900 AD) Ti content is low and coarser carbonate facies with detrital OM are deposited. - High values of Sr/Ti, Ca/Ti and TOC suggest a shallower palustrine environment.

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 1 . 6 4 Sr/Ti 1 . 2 0 . 8 0 5 0 0 0 0 0 0 0 . 4 0 Ca 2 5 0 0 0 0 0 1 0 0 0 0 Mn 0 5 0 0 0 4 0 0 0 0 0 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 During the LIA (1300-1850), laminated anoxic facies occur. Sr/Ti, Ca/Ti and TIC have high values around 1500 AD → Higher lake levels (similar pattern La Cruz lake).

200 1000 2000 Age 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 (cal yr AD) 8 Introduction 6 TOC 4 0 0 4 Location and 3 0 0 2 Geological Ca/Ti 2 0 0 0 settings 1 2 1 0 0 0 8 La Parra TIC 2 S E 1 . 6 4 M Sr/Ti 1 . 2 I 0 . 8 T 0 5 0 0 0 0 0 0 0 . 4 T 0 Ca N 2 5 0 0 0 0 0 E 1 0 0 0 0 C Mn E 0 5 0 0 0 4 0 0 0 0 0 R 0 Si 2 0 0 0 0 0 8 0 0 0 0 Ti 0 4 0 0 0 0 Instituto Pirenaico de Ecología (IPE) CSIC 0 LIA RP DA MCA 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 On recent times, detrital input proxies decrease and Ca/Ti increase slowly (as well as TOC and TIC) → Relative drop of lake levels