现代地质
現代地質
현대지질
GEOSCIENCE-JOURNAL OF GRADUATE SCHOOL CHINA UNIVERSITY OF GEOSCIENCES
2015年
2期
291-298
,共8页
杨慧君%王永%迟振卿%姚培毅%董进%田明中%刘瑾
楊慧君%王永%遲振卿%姚培毅%董進%田明中%劉瑾
양혜군%왕영%지진경%요배의%동진%전명중%류근
粒度特征%磁化率%环境演变%白洋淀%河北省
粒度特徵%磁化率%環境縯變%白洋澱%河北省
립도특정%자화솔%배경연변%백양정%하북성
grain size characteristic%magnetic susceptibility%environmental evolution%Baiyangdian%Hebei Province
基于河北省白洋淀地区老河头剖面沉积物的粒度组成与磁化率特征,结合6个AMS 14 C测年结果,重建了该地区25.5 cal ka BP以来的气候环境变化历史。结果显示,25.5 cal ka BP以来可以划分为7个较大的气候阶段:25.5~20.9 cal ka BP (610~515 cm),沉积环境以微弱的流水沉积和风力沉积为主;20.9~10.7 cal ka BP (515~388 cm),该区河流作用减弱,风力堆积加强;10.7~8.6 cal ka BP (388~335 cm),该区降水增加,白洋淀湖泊面积扩大,水位升高;8.6~7.2 cal ka BP (335~299 cm),风力作用加强,以风力堆积为主;7.2~3.2 cal ka BP(299~200 cm),沉积环境以稳定的湖相沉积为主,后期流水作用增强;3.2~1.3 cal ka BP(200~110 cm),该区流水作用显著,有泛滥性的洪水在此期间出现;1.3 cal ka BP至今(110~0 cm)降水减少,但流水作用仍然明显。
基于河北省白洋澱地區老河頭剖麵沉積物的粒度組成與磁化率特徵,結閤6箇AMS 14 C測年結果,重建瞭該地區25.5 cal ka BP以來的氣候環境變化歷史。結果顯示,25.5 cal ka BP以來可以劃分為7箇較大的氣候階段:25.5~20.9 cal ka BP (610~515 cm),沉積環境以微弱的流水沉積和風力沉積為主;20.9~10.7 cal ka BP (515~388 cm),該區河流作用減弱,風力堆積加彊;10.7~8.6 cal ka BP (388~335 cm),該區降水增加,白洋澱湖泊麵積擴大,水位升高;8.6~7.2 cal ka BP (335~299 cm),風力作用加彊,以風力堆積為主;7.2~3.2 cal ka BP(299~200 cm),沉積環境以穩定的湖相沉積為主,後期流水作用增彊;3.2~1.3 cal ka BP(200~110 cm),該區流水作用顯著,有汎濫性的洪水在此期間齣現;1.3 cal ka BP至今(110~0 cm)降水減少,但流水作用仍然明顯。
기우하북성백양정지구로하두부면침적물적립도조성여자화솔특정,결합6개AMS 14 C측년결과,중건료해지구25.5 cal ka BP이래적기후배경변화역사。결과현시,25.5 cal ka BP이래가이화분위7개교대적기후계단:25.5~20.9 cal ka BP (610~515 cm),침적배경이미약적류수침적화풍력침적위주;20.9~10.7 cal ka BP (515~388 cm),해구하류작용감약,풍력퇴적가강;10.7~8.6 cal ka BP (388~335 cm),해구강수증가,백양정호박면적확대,수위승고;8.6~7.2 cal ka BP (335~299 cm),풍력작용가강,이풍력퇴적위주;7.2~3.2 cal ka BP(299~200 cm),침적배경이은정적호상침적위주,후기류수작용증강;3.2~1.3 cal ka BP(200~110 cm),해구류수작용현저,유범람성적홍수재차기간출현;1.3 cal ka BP지금(110~0 cm)강수감소,단류수작용잉연명현。
Laohetou profile is located in the west of Baiyangdian depression.A 610 centimeter-deep sediment profile was studied in this paper.The AMS 14 C measured data revealed that the sediment profile deposited since 25.5 cal ka BP.Combined with chronological data,grain size characteristics,susceptibility and sedimentary characteristics,the evolutionary process and environment features during the past 25.5 cal ka BP were recon-structed.Results showed that there were seven stages as following.25.5 -20.9 cal ka BP(610-515 cm)is a fluvial facies and wind accumulation period;in 20.9-10.7 cal ka BP (5 15 -388 cm),fluvial action is weak-ened,and wind accumulation may be strengthened;in 10.7-8.6 cal ka BP (388-335 cm),precipitation in-creases and water accumulates,lakes expanding during this stage;8.6 -7.2 cal ka BP (335 -299 cm)is a wind accumulation period;7.2-3.2 cal ka BP(299-200 cm)is a lacustrine facies period;3.2-1.3 cal ka BP(200-1 10 cm)is a fluvial facies period;from 1.3 cal ka BP to now(1 10-0 cm),the precipitation decrea-ses,but fluvial function is still obvious.