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Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record

Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record. Moreno (1,2), H. Stoll (3), I. Cacho (4), Montserrat Jiménez-Sánchez (3), Carlos Sancho (5), Ánchel Belmonte (5), R. L. Edwards (1), E. Ito (1), B. L. Valero-Garcés (2)

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Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record

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  1. Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record • Moreno (1,2), H. Stoll (3), I. Cacho (4), Montserrat Jiménez-Sánchez (3), Carlos Sancho (5), Ánchel Belmonte (5), R. L. Edwards (1), E. Ito (1), B. L. Valero-Garcés (2) • (1) Limnological Research Center, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 (USA) • (2) Pyrenean Institute of Ecology - CSIC, Apdo. 202, 50080 Zaragoza, (Spain), • (3) Departamento de Geologia, Universidad de Oviedo, C/ Arias de Velasco, s/n 33005 Oviedo (Spain), • (4) University of Barcelona, C/ Marti i Franquès s/nº, 28080 Barcelona (Spain), • (5) Departamento de Ciencias de la Tierra, Facultad de Ciencias. Universidad de Zaragoza (Spain),

  2. Outline • Speleothems as exceptional paleoclimate archives • Study sites in the north of the Iberian Peninsula • Main questions • Some preliminary results… • Orbital scale • Last deglaciation main trends • Early Holocene abrupt changes • Conclusions A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  3. Speleothems as exceptional paleoclimate archives • Advantages • - Absolute dating by using the U-Th desintegration series (0-500 kyrs) • High precipitation rate (banding) –abrupt/rapid climate changes • - Good records of temperature and precipitation (stable isotopes, trace metals, growth rates…) • Disadvantages • - Only in karstic systems • System monitoring is required (lot of time and money….) • Presence of hiatus in dry or cold climates A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  4. Speleothems as exceptional paleoclimate archives Fairchild et al., 2006 A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  5. Speleothems as exceptional paleoclimate archives 2 initial assumptions: - Closed system to U and Th - Initial 230Th = 0 (“pure” samples, with low detrital) Some sources of errors: - Low U content (depends on the type of limestone) - High 232Th (high 230Th initial) - Post-precipitation effects A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  6. Air temperature variations 0.34‰/ºC Variability in the precipitation sources NAO; glacial vs interglacial Amount of precipitation d13C values of the carbonate bedrock (fixed values) d13C Soil processes and residence time d13C values of the soil CO2 Type of vegetation overlying the cave (C3 vs C4) Vegetation cover overlying the cave Marine aerosols – distance to the coast Mg/Ca, Sr/Ca, Ba/Ca Prior calcite precipitation (link to dry/wet climates) Speleothems as exceptional paleoclimate archives Diagenetic processes (evaluated by petrography to discard re-crystallization) Non-equilibrium fractionation (evaluated by d13C vs d18O correlation, replication or Hendy test) Other fractionation (eg. evaporation of water in the soil or vadose zone) d18O Cave Tª (seasonally stable, long-term variations can modulate the signal) d18O of rainfall A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  7. Cueva 5 de Agosto Cueva de las Güixas Sima de Estebán Felipe Cueva de Molinos El Pindal and Calabrez caves Study sites in the north of the Iberian Peninsula Zonas calcáreas CAVECAL-CICYT: Cambios climáticos rápidos en la Península Ibérica basados en calibración de indicadores, series instrumentales largas y análisis de alta resolución de registros en espeleotemas. DGA-LaCaixa: Formaciones de espeleotemas en Aragón: una innovadora aproximación a la reconstrucción del clima de los últimos milenios. A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  8. R2 = 0.85 Pathway Old fluvial channel - + non-dolomitic limestones of the Carboniferous Barcaliente Formation EL PINDAL Fluviokarstic and gravity features Speleothems Dripstone Block accumulations Flowstone Mud deposits Complex Old alluvial deposits Gours Jiménez-Sánchez et al., 2002 A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  9. 5 de Agosto • First stalagmites dated from the Spanish Pyrenees. • High altitude cave (1664 m) • Monitoring in progress (temperature, rainfall, dripwaters) A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  10. Main questions 1) Temporal and spatial reconstruction of main abrupt changes in the Northern Iberian Peninsula during the Pleistocene and Holocene 2) Interpretation of main mechanisms of abrupt climate change in the past, including phenomena affecting the most recent millennia (NAO, solar variability…) 3) Response of terrestrial ecosystems (hydrology, vegetation) to abrupt climate changes at different timescales (orbital, millennial, decadal) A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  11. Espeleothems from 5 de Agosto Cave (Central Pyrenees) only growth during short periods associated to interglacials: OIS 1, OIS 7, OIS 9, OIS 11. Surprisingly, there is no sample (after dating 16 stalagmites) growing during OIS 5 At an orbital-scale A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  12. At an orbital-scale Isotopes: d18O values very similar in the three interglacials; d13C has higher variability (particularly, OIS 7) • Identify the growth periods as the warmer and wetter intervals • Compare duration and characteristics of the last interglacials • Look for an “analogous” for the Holocene (OIS 5??, OIS 11?) A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  13. During last deglaciation CAN sample covers from 25 to 8 kyrs ago with an interruption during the Mystery Interval (Denton, 2005), a particular time period characterized by an increase in sea level but colder temperatures in Greenland and North Atlantic than during the LGM. CANDELA We would expect a very cold, and probably dry, scenario for southern Europe. A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  14. GI-1 HOLOCENE GS-1 Gi-2 GS-2a GS-2b GS-2C YD LGM HE2 H1 OD IACP PB Wetter NAO - 7.4 9.2 10.3 8.2 HIATUS Mystery interval HIATUS Drier NAO + During last deglaciation Age (years BP) d18O (‰) NGRIP (GCC05) (Rassmussen et al. QSR 2008) d13C (‰) d18O (‰) CANDELA MARIA A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  15. YD LGM HE2 H1 OD IACP PB During last deglaciation GI-1 HOLOCENE GS-1 Gi-2 GS-2a GS-2b GS-2C Wetter 7.4 9.2 10.3 8.2 d18O (‰) NGRIP (GCC05) (Rassmussen et al. QSR 2008) Ba/Ca d13C (‰) Drier CANDELA MARIA A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  16. COLD 11.2 7.4 8.3 9.4 10.2 WARM WET DRY During the Early Holocene Bond et al., 2001 HSG (detrended) d13C (‰) d18O (‰) A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  17. 9.1 9.3 10 10.4 10.9 PB 9.2 9.9 10 9.4 9.6 10.3 During the Early Holocene NGRIP Dongge Cave (Dykoski et al., 2005) d18O (‰) d18O (‰) MARÍA (this study) Dongshiya Cave (Cai et al., 2008) d18O (‰) d18O (‰) A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

  18. Conclusions • Speleothem records from Northern Spain are excellent paleoclimate records of past hydrological variability that need to be studied with further detail • Growing periods in the Central Pyrenees are related to some interglacials pointing to the most humid and the warmest intervals for the last 400 kyrs. • The driest period for the last 25 kyrs is the “mystery interval” as indicated by the hiatus • Paleohydrological and vegetational response to the abrupt changes duringdeglaciation (HE1, B/A, oldest and older Dryas, IACP) and Early Holoceneabrupt changes • NAO-type mechanism behind abrupt climate changes recorded in the Iberian Peninsula? A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

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