Preliminary paleoclimate reconstruction based on a 12,500 year old speleothem from Vancouver Island,Canada: stable isotopes and U–Th disequilibrium dating |
| |
| Authors: | Daniel Marshall Bassam Ghaleb Robert Countess Janet Gabities |
| |
| Institution: | 1. Department of Geology, University of Oviedo, Oviedo 33005, Spain;2. Instituto Pirenaico de Ecología (IPE)-CSIC, Avda. Montañana 1005, 50059 Zaragoza, Spain;3. Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA;4. Institute of Global Environmental Change, Xian Jiaotong University, Xian 710049, China;1. MIPT Life Science Center, Institutsky pereulok 9, Dolgoprudny, Moscow Region 141700, Russia;2. iCeMS Research Building, Yoshida Honmachi, Sakyo-ku, Kyoto 606-8501, Japan;1. U.S. Geological Survey Geosciences and Environmental Change Science Center, Denver, CO, USA;2. University of Illinois-Chicago, Department of Earth and Environmental Science, Chicago, IL, USA;3. U.S. Geological Survey Volcano Science Center, Menlo Park, CA, USA;4. University of Minnesota-Duluth, Department of Earth and Environmental Sciences and Large Lakes Observatory, Duluth, MN, USA;5. Idaho State University, Departments of Biological Sciences and Geosciences, Pocatello, ID, USA;6. University of Pittsburgh, Department of Geology and Environmental Science, Pittsburgh, PA, USA |
| |
| Abstract: | A combination of δ13C and δ18O analyses with U–Th disequilibrium dating on a stalagmite and groundwater from the deep and extensive Arch Cave network on northeastern Vancouver Island has produced a preliminary 12,200 y paleoclimatic profile. Speleothem depositional rates vary from 6 to 41 mm/ka and are consistent with the “Hendy” test for speleothem deposition under high-humidity equilibrium conditions. Relative to present day conditions, warmer periods are indicated at the end of the Younger Dryas, during the Holocene maximum, a possible Medieval Warming event, with the warmest period represented by a narrow peak at 8000 y BP. Relatively cooler periods are recorded at 3500, 8200, 9300 and 11,500 y BP with indications of minor cooling during the Little Ice Age and indications of relatively dry conditions during the earlier part of the Younger Dryas followed by warmer wetter conditions. The profile shows excellent agreement with other paleoclimatic indicators locally, most notably some partial speleothem records from Vancouver Island and Oregon, and some high-resolution global records such as the Greenland ice cores and speleothems from the Hulu Cave, China. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
