Holocene Profile Sediment Of Tianhushan In Fujian And Its Paleoclimate Significance

Holocene is the most recent period in the geological history,also the period which human society emergence and development,so choosing the suitable area and index to study the Holocene climate change process is of great significance for predicting the future climate change.Fujian Province is located in southeastern China,is the key area to invest the evolution history of Asian Monsoon.However,the dynamical processes that govern its complex spatiotemporal variability are not sufficiently understood to predict its behaviour,during the Holocene.Here,a peat record in intermountain basin of Fujian Province was used to discussed,with the analysis of sedimentary stratum,TOC,sediment color,carbon isotope(?13C).?nitrogen isotope(?15N),combined with AMS14C dating,the Holocene climate change of study area was divided into three phases:(1)The depth of the section is about 217-173 cm,10.6 cal kaBP-10 cal kaBP,for the early holocene cold wet period,with positive ?13C and ?15N values,low values of TOC,and the high values of L*,indicates that the regional climate have a gradual warming trend.(2)The depth of the section is about 173-125 cm,10 cal kaBP-3.3 cal kaBP,this stage have the negative ?13C and ?15N values,high values of TOC and the sedimentary types is clay layer,shows that this term is a warm period,this stage is typical limnetic facies,instruct that the Asian monsoon is strong with abundant rainfall.(3)Section depth of about 125-0 cm,3.3 cal kaBP to present.With Asian monsoon recession in Late Holocene,the climate changed from warm wet to dry quickly.This stage can be divided into three small stages:(I)3.3 cal.kaBP-2.8 cal.kaBP,this stage have the positive ?13C and ?15N values,TOC values fluctuation decreased,indicating less precipitation on the previous stage.(II)2.8 cal.kaBP-0.7 cal.kaBP,it is a short warm period,this stage have the negative ?13C and ?15N values,higher TOC values,and the L*values decreased.(?)0.7 cal.kaBP to now,this stage have the positive ?13C and ?15N values,TOC values gradually reduce,L*increased,The ?18O at Dongge cave is heavier,Indicate that the regional climate continues the cool and dry period.Tianhushan peat profile reveals the climate change in northern intermountain areas since Holocene,Fujian proprovince.In a nutshell:The characters from typical peat deposits at bottom shallow deposition at top,is consistent with gradually weakened trend of monsoon since Holocene in east Asia.The environmental evolution information recorded by Tianhushan sediment,could provide the basis for future trend forecast regional precipitation.