EGU2020-4028, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-4028
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Stalagmite geochemical proxy-inferred precipitation records over the past 800 years in northern Italy

C.-C. (River) Shen1,2, Hsun-Ming Hu1,2, Véronique Michel3,4, Patricia Valensi5, Horng-Sheng Mii6, Christoph Spötl7, Elisabetta Starnini8, Marta Zunino9, Takaaki Watanabe10, Tsuyoshi Watanabe10, Hsien-Chen Tsai1,2, Wen-Hui Sung1,2, and Wei-Yi Chien1,2
C.-C. (River) Shen et al.
  • 1High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC), Department of Geosciences, National Taiwan University, Taipei, Taiwan (river@ntu.edu.tw)
  • 2Research Center for Future Earth, National Taiwan University, Taipei, Taiwan
  • 3Université Côte d’Azur, CNRS, CEPAM, Nice, France
  • 4Université Côte d’Azur, CNRS, OCA, IRD, Géoazur, Valbonne, France
  • 5Sorbonne Universités, MNHN, CNRS, UPMC, UPVD, Paris, France; Musée de Préhistoire, Tourrette-Levens, France
  • 6Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
  • 7Institute of Geology, University of Innsbruck, Innsbruck, Austria
  • 8Archaeological Superintendency of Liguria, Via Balbi 10, Genova, Italy
  • 9Toirano Cave, Piazzale D. Maineri 1, Toirano, Italy
  • 10Department of Natural History Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan

We here present new 230Th-dated stalagmite multi-proxy records from Toirano cave (44˚ N, 8˚E), northern Italy, characterized by a semi-arid Mediterranean climate with humid winters and dry summers. Eleven U-Th ages was used to build the regional hydroclimate evolution over the past 800 years. Sr/Ca and Ba/Ca records show a similar pattern with an increasing trend at the end of Medieval Warm Period (MWP; 950-1250 C.E.) and a decreasing trend at the inception of Little Ice Age (LIA; 1300 to 1800 C.E). The temperature effect on the Sr partition coefficient in calcite is negligible and no significant influence of deposition rate on Sr/Ca and Ba/Ca is observed. The high degree of co-variation between the two records (r = 0.91; n = 212) suggest the variation should be mainly governed by prior calcite precipitation (PCP). Dry conditions lead to a longer water residence time in the epikarst, enhanced CO2 degassing and decreasing drip rate, resulting in high Sr/Ca and Ba/Ca ratios due to the preferential removal of Ca during PCP. Our results suggest a dry period during the transition of MCA and LIA in our region.

How to cite: Shen, C.-C. (., Hu, H.-M., Michel, V., Valensi, P., Mii, H.-S., Spötl, C., Starnini, E., Zunino, M., Watanabe, T., Watanabe, T., Tsai, H.-C., Sung, W.-H., and Chien, W.-Y.: Stalagmite geochemical proxy-inferred precipitation records over the past 800 years in northern Italy, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4028, https://doi.org/10.5194/egusphere-egu2020-4028, 2020