A cool temperate climate on the Antarctic Peninsula through the latest Cretaceous to early Paleogene
A cool temperate climate on the Antarctic Peninsula through the latest Cretaceous to early Paleogene
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DOI：
10.1130/g35512.1
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发表时间：
2014-07
期刊：
影响因子：
5.8
通讯作者：
D. Kemp;S. Robinson;J. Crame;J. Francis;J. Ineson;R. Whittle;V. Bowman;C. O’Brien
中科院分区：
文献类型：
--
作者：
D. Kemp;S. Robinson;J. Crame;J. Francis;J. Ineson;R. Whittle;V. Bowman;C. O’Brien
限制过去全球气温的波动对于我们理解地球气候演变至关重要。海洋代理主导了过去温度重建的记录，而我们对大陆气候的了解相对较差，特别是在南极洲等高纬度地区。最近开发的MBT/CBT（支链四醚的甲基化指数/支链四醚的环化率）古温度计提供了以陆地宏观口头代理通常无法提供的时间分辨率量化古代大陆气候的机会。在这里，我们将 MBT/CBT 代理的应用扩展到白垩纪，通过从南极洲西摩岛扩展的沉积序列呈现古温度，跨越最新的马斯特里赫特阶和古新世。我们的数据表明，跨越白垩纪-古近纪边界的南极半岛存在相对稳定、持续的凉爽温带气候。这些新数据有助于阐明在古近纪晚期主要冰盖发育之前，南极洲在白垩纪-古近纪边界上地球上最明显的生物重组之一的气候演变。我们的工作强调了古近纪早期南部高纬度地区气候可能存在时间和/或空间异质性。
Constraining past fl uctuations in global temperatures is central to our understanding of the Earth’s climatic evolution. Marine proxies dominate records of past temperature reconstructions, whereas our understanding of continental climate is relatively poor, particularly in high-latitude areas such as Antarctica. The recently developed MBT/CBT (methylation index of branched tetraethers/ cyclization ratio of branched tetraethers) paleothermometer offers an opportunity to quantify ancient continental climates at temporal resolutions typically not afforded by terrestrial macrofl oral proxies. Here, we have extended the application of the MBT/CBT proxy into the Cretaceous by presenting paleotemperatures through an expanded sedimentary succession from Seymour Island, Antarctica, spanning the latest Maastrichtian and Paleocene. Our data indicate the existence of a relatively stable, persistently cool temperate climate on the Antarctic Peninsula across the Cretaceous-Paleogene boundary. These new data help elucidate the climatic evolution of Antarctica across one of the Earth’s most pronounced biotic reorganizations at the Cretaceous-Paleogene boundary, prior to major icesheet development in the late Paleogene. Our work emphasizes the likely existence of temporal and/or spatial heterogeneities in climate of the southern high latitudes during the early Paleogene.