A multi-proxy approach to determine Antarctic terrestrial palaeoclimate during the Late Cretaceous and Early Tertiary
A multi-proxy approach to determine Antarctic terrestrial palaeoclimate during the Late Cretaceous and Early Tertiary
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DOI：
10.1016/j.palaeo.2005.03.011
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发表时间：
2005-06
期刊：
影响因子：
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通讯作者：
I. Poole;D. Cantrill;T. Utescher
中科院分区：
文献类型：
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作者：
I. Poole;D. Cantrill;T. Utescher
南极半岛北部地区的白垩纪和第三纪序列中都有丰富的木化石。木材化石代表了曾经在南纬 59-62° 的南部高古纬度地区生长的植被遗迹，经历了从白垩纪晚期全球变暖到冰川作用开始前的始新世中期凉爽时期气候普遍衰退的过程。这项研究利用了有史以来最大的南极针叶树和被子植物数据集，以便更清楚地了解古气候。记录的参数包括年平均气温、年平均温差、冷月平均、暖月平均、年平均降水量。利用解剖学（地貌）特征对化石木材组合进行了分析，以确定从科尼亚阶-坎帕阶到始新世中期的古气候变量。这些结果与来自化石植物群（由叶子、木材和孢粉形态组成）共存分析的数据以及基于叶子面貌特征的已发表数据进行了比较。这些研究表明，白垩纪晚期相对温暖和湿润，在古新世早期变得更加干燥和凉爽，随后在古新世晚期恢复到温暖和湿润的条件。在始新世期间，气候再次变得相对凉爽和干燥。在周围海洋温度波动和全球气候变化模式的背景下，讨论了这两种方法得出的差异以及其他已发表的数据。
Fossil wood is abundant throughout the Cretaceous and Tertiary sequences of the northern Antarctic Peninsula region. The fossil wood represents the remains of the vegetation that once grew at the southern high palaeolatitudes at 59–62°S through the general decline in climate, from the Late Cretaceous global warmth through to the mid-Eocene cool period prior to the onset of glaciation. This study draws on the largest dataset ever compiled of Antarctic conifer and angiosperm woods in order to derive clearer insights into the palaeoclimate. Parameters including mean annual temperature, mean annual range in temperature, cold month mean, warm month mean, mean annual precipitation are recorded. The fossil wood assemblages have been analysed using anatomical (physiognomic) characteristics to determine the palaeoclimate variables from the Coniacian–Campanian to the middle Eocene. These results are compared with data derived from Coexistence Analysis of the fossil floras (composed of leaves, wood and palynomorphs) and published data based on leaf physiognomic characters. These studies indicate a relatively warm and wet Late Cretaceous that becomes drier and cooler in the Early Paleocene and subsequently returns to warmer, wetter conditions by the latest Early Paleocene. During the Eocene the climate becomes relatively cool and dry once again. The discrepancies obtained from these two methods coupled with other published data are discussed in the context of the fluctuations in the temperatures of the surrounding oceans and global patterns of climate change.