地球学报
地毬學報
지구학보
ACTA GEOSCIENTIA SINICA
2013年
1期
87-94
,共8页
边彦明%余佳%邵兆刚%韩建恩%贺承广
邊彥明%餘佳%邵兆剛%韓建恩%賀承廣
변언명%여가%소조강%한건은%하승엄
佩枯错%晚更新世以来%湖相沉积%环境变化
珮枯錯%晚更新世以來%湖相沉積%環境變化
패고착%만경신세이래%호상침적%배경변화
Paiku Co%late Pleistocene%lacustrine deposit%environmental change
西藏佩枯错盆地晚更新世以来河湖相沉积剖面的孢粉分析显示,该地区在晚更新世早期的127—72 ka B.P.时期,气候温和湿润,植被以针阔叶混交林为主;至66—56 ka B.P.时期,气候转变为温凉略干,植被转为疏林草原;在56—49 ka B.P.时期,气候温凉潮湿,植被又转为针阔叶混交林为主的森林草原;而在49—46 ka B.P.时期,气候温和偏干,植被转为疏林草原;在46—31 ka B.P.时期,气候寒凉湿润,植被表现为温度进一步下降的疏林草原;在31—15 ka B.P.时期,环境向寒冷方向发展,植被转为高寒草原;自11 ka B.P.(全新世初期)开始,气候由温暖偏干转变为温凉偏湿,植被由灌丛草原转变为森林灌丛草原.这表明自晚更新世以来,该区气候环境是在逐渐变干的总趋势上,经历了多次明显的冷暖与干湿波动.
西藏珮枯錯盆地晚更新世以來河湖相沉積剖麵的孢粉分析顯示,該地區在晚更新世早期的127—72 ka B.P.時期,氣候溫和濕潤,植被以針闊葉混交林為主;至66—56 ka B.P.時期,氣候轉變為溫涼略榦,植被轉為疏林草原;在56—49 ka B.P.時期,氣候溫涼潮濕,植被又轉為針闊葉混交林為主的森林草原;而在49—46 ka B.P.時期,氣候溫和偏榦,植被轉為疏林草原;在46—31 ka B.P.時期,氣候寒涼濕潤,植被錶現為溫度進一步下降的疏林草原;在31—15 ka B.P.時期,環境嚮寒冷方嚮髮展,植被轉為高寒草原;自11 ka B.P.(全新世初期)開始,氣候由溫暖偏榦轉變為溫涼偏濕,植被由灌叢草原轉變為森林灌叢草原.這錶明自晚更新世以來,該區氣候環境是在逐漸變榦的總趨勢上,經歷瞭多次明顯的冷暖與榦濕波動.
서장패고착분지만경신세이래하호상침적부면적포분분석현시,해지구재만경신세조기적127—72 ka B.P.시기,기후온화습윤,식피이침활협혼교림위주;지66—56 ka B.P.시기,기후전변위온량략간,식피전위소림초원;재56—49 ka B.P.시기,기후온량조습,식피우전위침활협혼교림위주적삼림초원;이재49—46 ka B.P.시기,기후온화편간,식피전위소림초원;재46—31 ka B.P.시기,기후한량습윤,식피표현위온도진일보하강적소림초원;재31—15 ka B.P.시기,배경향한랭방향발전,식피전위고한초원;자11 ka B.P.(전신세초기)개시,기후유온난편간전변위온량편습,식피유관총초원전변위삼림관총초원.저표명자만경신세이래,해구기후배경시재축점변간적총추세상,경력료다차명현적랭난여간습파동.
Based on an analysis of Sporopollen assemblages of fluvial-lacustrine sediments in Paiku Co basin of Tibet since late Pleistocene, the authors divided the climate evolution into seven stages as follows: During 127–72 ka B.P, the climate was warm and humid, and broad-leaved and coniferous mixed forests constituted the main vegetation here. Between 66 ka B.P and 56 ka B.P., the climate turned into warm and dry, and the vegetation changed into wood grassland. During 56–49 ka B.P., the climate was characterized again by wetness and warmness and broad-leaved and coniferous mixed forest-dominated forest steppe. From 49 to 46 ka B.P., the climate was temperate and dry, and the vegetation turned into wood grassland. Between 46 and 31 ka B.P, the basin had a cool and wet climate, and the wood grassland here was in a lower temperature environment. During 31–15 ka B.P., the climate turned into cold, and the vegetation displayed alpine grassland. Since 11 ka B.P, the climate here has turned from warm and dry to cool and wet, and the vegetation has changed from bushveld into forest bushveld. It is thus concluded that the climate and environment in this region have experienced several evident cold-warm and dry-humid fluctuations in the general trend of gradually becoming arid.