A latest Cretaceous to earliest Paleogene dinoflagellate cyst zonation from Antarctica, and implications for phytoprovincialism in the high southern latitudes
A latest Cretaceous to earliest Paleogene dinoflagellate cyst zonation from Antarctica, and implications for phytoprovincialism in the high southern latitudes
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DOI：
10.1016/j.revpalbo.2011.11.004
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发表时间：
2012-02-01
影响因子：
1.9
通讯作者：
Haywood, Alan M.
中科院分区：
文献类型：
--
作者：
Bowman, Vanessa C.;Francis, Jane E.;Haywood, Alan M.
南极半岛詹姆斯罗斯盆地西摩岛南部（南纬65度）出露了世界上最厚的白垩纪最上部至古近纪最下部（马斯特里赫特阶至达尼阶）沉积序列。这一含油气的浅海层序跨越古近系-古近系界线，可以对保存完好的海相孢粉进行高分辨率分析。以往南极地区古近纪-古近纪海洋孢粉组合的相关性依赖于新西兰和澳大利亚南部的甲藻孢囊生物带。西摩岛南部继承的年龄模型进行了改进，并放置在地层背景下的中期到高南部palaeolatitudes。对西摩岛南部一个新的1102 m连续地层剖面进行了定量孢粉分析，该剖面包括最上部的Snow Hill Island组和洛佩斯de Bertodano组（Marambio群）。我们提出了第一个正式的晚马斯特里赫特早期Danian甲藻孢囊分带计划南极基于这种特殊的继承。新划分了两个新的晚马斯特里赫特带（包括三个亚带）和一个新的早丹尼期带。最古老的地层与新西兰的马斯特里赫特晚期有很好的对应关系。在更广泛的背景下，一个新的南极省的基础上马斯特里赫特到Danian甲藻孢囊的建议，其中不包括南美洲南部的海洋孢粉植物。这一解释得到了南极洲周围洋流模型的支持，并意味着南美洲南部和塔斯曼海之间的南极洲海洋连接不受限制。(C)2011 Elsevier B. V.保留所有权利。
The thickest uppermost Cretaceous to lowermost Paleogene (Maastrichtian to Danian) sedimentary succession in the world is exposed on southern Seymour Island (65 degrees South) in the James Ross Basin, Antarctic Peninsula. This fossiliferous shallow marine sequence, which spans the Cretaceous-Paleogene boundary, has allowed a high-resolution analysis of well-preserved marine palynomorphs. Previous correlation of Cretaceous-Paleogene marine palynomorph assemblages in the south polar region relied on dinoflagellate cyst biozonations from New Zealand and southern Australia. The age model of the southern Seymour Island succession is refined and placed within the stratigraphical context of the mid to high southern palaeolatitudes. Quantitative palynological analysis of a new 1102 m continuous stratigraphical section comprising the uppermost Snow Hill Island Formation and the Lopez de Bertodano Formation (Marambio Group) across southern Seymour Island was undertaken. We propose the first formal late Maastrichtian to early Danian dinoflagellate cyst zonation scheme for the Antarctic based on this exceptional succession. Two new late Maastrichtian zones, including three sub-zones, and one new early Danian zone are defined. The oldest beds correlate well with the late Maastrichtian of New Zealand. In a wider context, a new South Polar Province based on Maastrichtian to Danian dinoflagellate cysts is proposed, which excludes most southern South American marine palynofloras. This interpretation is supported by models of ocean currents around Antarctica and implies an unrestricted oceanic connection across Antarctica between southern South America and the Tasman Sea. (C) 2011 Elsevier B.V. All rights reserved.