The influence of volcanism on paleoclimate in the northeast of China: Insights from Jinchuan peat, Jilin Province, China
Just like contemporary sediments, peat itself is a good repository of information about climate change, the effects of volcanic activity on climate change have been truly recorded in peat, since it is a major archive of volcanic eruption incidents. A section of sand was identified as tephra from the Jinchuan peat, Jilin Province, China, for the grains look like slag with surface bubbles and pits, characterized by high porosity, and loose structure with irregular edges and corners. According to the peat characteristics of uniform deposition, the tephra was dated at 2002-1976 a B.P. by way of linear interpolation, so the time of volcanic eruption was 15 B.C.-26 A.D. (the calibrated age). While the geochemical characteristics of tephra in this study are quite the same as those of tephra from the Jinlongdingzi volcano at Longgang and from alkaline basaltic magma, with the contents of SiO2<55%, and the similar contents to Al2O3 and Fe, but the contents of Na2O>K2O. We speculated that the tephra in this study came from the Longgang volcano group. Compared with 11 recorded volcanic eruption events as shown on the carbon and oxygen isotope curves of the Jinchuan peat cellulose, it is obviously seen that adjacent or large-scale volcanic eruptions are precisely corresponding to the minimum temperature and humidity. It seems that these volcanic eruptions indeed affected the local climate, leading to the drop of regional temperature and humidity. As a result, there was prevailing a cold and dry climate there, and all these changes can be well recorded in peat. So the comparison of volcanic eruption events with information about climate change developed from peat, can provide strong evidence for the impact of volcanism on climate change.
作 者： MAO Xumei CHENG Shenggao HONG Yetang ZHU Yongxuan WANG Fenglin 作者单位： MAO Xumei,CHENG Shenggao,WANG Fenglin(School of Environmental Studies, China University of Geosciences, Wuhan 430074, China)HONG Yetang,ZHU Yongxuan(The State Key Laboratory of Environment Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China)
刊 名： 中国地球化学学报（英文版） 英文刊名： CHINESE JOURNAL OF GEOCHEMISTRY 年，卷(期)： 2009 28(2) 分类号： P59 关键词： tephra peat 14C age volcanic eruption climate change