DATE2016-05-30 10:44:08
IDABSTRACT20160530104408-1036
CONTACTzanchetta@dst.unipi.it
PRESENTATIONPOSTER
INVITED0
IDSESSION3
TITLEHOLOCENE CLIMATE VARIABILITY FROM RIO MARTINO CAVE (WESTERN ALPS, NORTHERN ITALY)
AUTHORSEleonora Regattieri (1,6), Giovanni Zanchetta (2,6), Ilaria Isola (3), Russell Neil Drysdale (4), Zanella Elena (5), Hellstrom John (4), Boschi Chiara (6), Luca Lanci (7), Federico Magri (8)
AFFILIATIONS
  1. Igag-cnr Rome (Italy)
  2. University Of Pisa Pisa (Italy)
  3. Ingv Pisa (Italy)
  4. The University Of Melbourne Melbourne (Australia)
  5. University Of Turin Turin (Italy)
  6. Igg-cnr Pisa (Italy)
  7. University Of Urbino Urbino (Italy)
  8. Associazione Gruppi Speleologici Piemontesi Torino (Italy)
ABSTRACTThe Alpine region currently experiences complex climatic conditions and presumably it was the case for the Holocene. For depicting the climatic evolution of the western sector of the Alps, several flowstone cores were retrieved from Rio Martino Cave (Piemonte, Northern Italy, ca. 1530 m a.s.l.) in the upper Po Valley, where the climate is dominated by North Atlantic synoptic systems. U/Th dating of flowstones indicates a phase of deposition starting at the beginning of the Holocene. Two cores were intensively studied using a multi-proxy approach (stable isotopes and rock magnetism). The oxygen isotope record spans from ca. 10 ka to 0.5 ka and shows substantial variability, which is interpreted as changes in rainfall isotopic composition recharging the cave catchment. Variations in carbon isotopes instead are interpreted as reflecting the degree of soil development. A long-term trend in oxygen isotope ratio is apparent, with relatively low values persisting from the commencement of deposition until ca. 6 ka. From 6 to 3 ka the oxygen isotope ratio increases gradually before decreasing again from 3 ka onward. Carbon isotope ratio shows a good degree of correlation with oxygen. Superimposed on this trend are numerous centennial-scale oscillations which may reflect alternating periods of drier and wetter conditions. Both stable isotope records and magnetic susceptibility and remanence intensity, which mainly depend on the detrital content inside the speleothem, show an interesting similarity with increases in the frequency of floods as recorded by recent compilations of lake records
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