發(fā)布時間：2018-07-21 13:35

【摘要】：漸新世全球氣候總體上發(fā)生了降溫,代表著地球新生代早期的一個"冰室"。植物對氣候變化反應敏感,作為地質(zhì)時期的產(chǎn)物,植物化石能夠反映當時陸地氣候的變遷。本文利用共存分析法(Coexistence Approach,CA)對中國5個漸新世植物群的年均溫進行了恢復,并利用葉緣分析法(Leaf Margin Analysis,LMA)對其中木本雙子葉植物不少于15種的4個植物群年均溫進行了分析。兩類方法的推測值整體表現(xiàn)為CA的年均溫相對高于LMA值,其中葉緣分析法東亞模型得出的年均溫高于中國模型值。通過對能影響兩類方法結果的因素分析,推測CA恢復的值能更好地代表化石點當時的年均溫,咸水河組下段植物群為13.3~15.6℃,楊連屯組大橋段植物群為12.1~19.4℃,三合植物群為14.3~16.8℃,景谷植物群為19.7~23.7℃,寧明組植物群為22.0~23.6℃。由于CA恢復的年均溫都高于當?shù)噩F(xiàn)在的年均溫,推測漸新世時,雖然全球溫度自始新世以來整體相對降低,但還是比現(xiàn)在溫暖。
[Abstract]:The global climate of Oligocene generally cooled, representing an ice chamber in the early Cenozoic. Plants are sensitive to climate change. As a product of geological period, plant fossils can reflect the changes of terrestrial climate at that time. The annual mean temperature of five Oligocene flora in China was recovered by means of coexisting Approacha and leaf margin analysis (LMA) was used to analyze the annual mean temperature of 4 species of woody dicotyledonous plants. The predicted values of the two methods are as a whole that the average annual temperature of CA is relatively higher than that of LMA, and the average annual temperature of the East Asian model of leaf margin analysis is higher than that of the Chinese model. Based on the analysis of the factors that affect the results of the two methods, it is inferred that the CA recovery value can better represent the average annual temperature of the fossil point at that time. The flora of the lower section of the Xianshuihe formation is 13.315.6 鈩，

本文編號：2135693