Dinoflagellate cysts from the Eocene/Oligocene transition in the Southern Ocean; results from ODP Leg 189.
Dinoflagellate cysts from the Eocene/Oligocene transition in the Southern Ocean; results from ODP Leg 189.
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南大洋始新世/渐新世过渡时期的甲藻包囊；
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
M. Fuller
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作者：
A. Sluijs;H. Brinkhuis;C. Stickley;J. Warnaar;G. Williams;M. Fuller
在大洋钻探计划189航次的1170-1172点，气候关键的始新世-渐新世(E-O)过渡没有任何钙质微化石，但含有丰富的海洋有机壁沟鞭藻孢囊(恐囊)和硅藻组合，适合进行详细的生物地层学和古环境分析。由此产生的有史以来第一个综合的恐囊/硅藻磁性地层学使得所有LEG 189个地点(包括1168个地点)之间的E-O间隔得到了可靠的对比。我们的关联表明，塔斯马尼亚门户的(深)开放在整个塔斯马尼亚地区是准同步的，始于约35.5 Ma。在1170-1172点，可以从数量上区分出三个不同的恐囊组合，它们反映了塔斯马尼亚地区从前三角洲环境到深海海洋环境的E-O转换过程中相对快速和显著的阶段性环境变化。此外，随着门户的加深，在南部和东部地点1170-1172，典型的南极地方性组合被更多世界性的恐囊群落所取代。与之形成鲜明对比的是，在塔斯马尼亚西部的1168号站位，在E-O过渡期间，几乎没有南极特有的类群。在1170-1172点，南极特有的恐囊组合(横贯北极植物群)在~35.5 Ma急剧转变为更具世界性的组合，具有更离岸的特征，反映了Ar1Sluijs，A.，Brinkhuis，H.，Stickley，C.E.，Warna，J.，Williams，G.L.和Fuller，M.，2003。南大洋始新世-渐新世过渡期的甲藻孢囊：ODP189航段的结果。在北卡罗来纳州埃克森，肯尼特，J.P.和马龙，M.J.(编辑)，Proc.ODPSci.结果，189，1-42[在线]。可从万维网获得：。[引用YYYY-MM-DD]2荷兰乌得勒支大学古植物学与孢粉学实验室，布达佩斯兰4,3584 CD，荷兰。通讯作者：A.Sluijs@Bio.uu.nl 3Lamont-Doherty地球观测站，9W路61号，邮政信箱1000，邮编：10964，美国。目前地址：卡迪夫大学地球、海洋和行星科学学院，邮编：914，加的夫CF10 3YE，英国。4大西洋地球科学中心，邮政信箱1006，达特茅斯NS B2Y 4A2加拿大。5夏威夷大学马诺阿分校地球物理和行星研究所，火奴鲁鲁，HI 96822，美国。初次接收时间：2002年11月13日接受日期：2003年7月15日网络发布时间：2003年10月22日189SR-104 A.Sluijs et AL。始新世-渐新世沟鞭藻包囊2个不同海洋和环境条件的竞争对手，与塔斯马尼亚门户的加深有关。反过来，这种组合在~34 Ma时变得更典型，在1172号站点更适合于离岸和/或上升流条件。在所有地点略年轻的沉积物中，几乎没有有机微体化石，反映了风选和氧化作用，预示着下一步海洋学发展。该阶段可能接近大洋缺氧(OI)-1δ18O(南极冰川)事件(~33.3 Ma)。在最早的渐新世北部1172号遗址的一个单一生产性样品中，已经恢复了一个相对温暖的水系大都市组合。这一方面与罗斯海同时代沉积物的发现形成了对比，在罗斯海，南极特有物种仍然占主导地位。在1172站的古地理位置和罗斯海之间的某个地方，在渐新世早期发生了强烈的表层水分异，可能反映了南极绕极流的开始。
At Ocean Drilling Program (ODP) Leg 189 Sites 1170–1172, the climatologically critical Eocene–Oligocene (E-O) transition is barren of any calcareous microfossils but contains rich marine organic walled dinoflagellate cyst (dinocyst) and diatom assemblages, suitable for detailed biostratigraphic and paleoenvironmental analysis. The resulting first-ever integrated dinocyst/diatom magnetostratigraphy allows confident correlation of the E-O interval between all Leg 189 sites, including Site 1168. Our correlations indicate that the (deep) opening of the Tasmanian Gateway occurred quasi-synchronously throughout the Tasmanian region, starting at ~35.5 Ma. At Sites 1170–1172, quantitatively, three distinct dinocyst assemblages may be distinguished that reflect the relatively rapid and pronounced stepwise environmental changes associated with the E-O transition in the Tasmanian region, from a prodeltaic setting to a deep marine pelagic setting. Moreover, synchronous with the deepening of the gateway, at the southern and eastern Sites 1170–1172, typical endemic Antarctic assemblages were replaced by more cosmopolitan dinocyst communities. In marked contrast, at Site 1168 off western Tasmania, endemic Antarctic taxa are virtually absent during the E-O transition. At Sites 1170–1172, the endemic Antarctic dinocyst assemblage (Transantarctic Flora) drastically changes into a more cosmopolitan assemblage at ~35.5 Ma, with a more offshore character, reflecting the ar1Sluijs, A., Brinkhuis, H., Stickley, C.E., Warnaar, J., Williams, G.L., and Fuller, M., 2003. Dinoflagellate cysts from the Eocene–Oligocene transition in the Southern Ocean: results from ODP Leg 189. In Exon, N.F., Kennett, J.P., and Malone, M.J. (Eds.), Proc. ODP, Sci. Results, 189, 1–42 [Online]. Available from World Wide Web: . [Cited YYYY-MM-DD] 2Laboratory of Palaeobotany and Palynology, Utrecht University, Budapestlaan 4, 3584CD Utrecht, The Netherlands. Correspondence author: A.Sluijs@bio.uu.nl 3Lamont-Doherty Earth Observatory, 61 Route 9W, PO Box 1000, Palisades NY 10964, USA. Present address: School of Earth, Ocean, and Planetary Sciences, Cardiff University, PO Box 914, Cardiff CF10 3YE, UK. 4Atlantic Geoscience Centre, PO Box 1006, Dartmouth NS B2Y 4A2 Canada. 5Hawaii Institute of Geophysics and Planetology, University of Hawaii at Manoa, Honolulu HI 96822, USA. Initial receipt: 13 November 2002 Acceptance: 15 July 2003 Web publication: 22 October 2003 Ms 189SR-104 A. SLUIJS ET AL. EOCENE–OLIGOCENE DINOFLAGELLATE CYSTS 2 rival of different oceanographic and environmental conditions associated with the deepening of the Tasmanian Gateway. In turn, this assemblage grades at ~34 Ma into one more typical for even more offshore and/or upwelling conditions at Site 1172. In slightly younger deposits at all sites, organic microfossils are virtually absent, reflecting winnowing and oxidation, indicative of a next step of oceanographic development. This phase may be dated as close to the Oceanic Anoxic (Oi)-1 δ18O (Antarctic glaciation) event (~33.3 Ma). In a single productive sample from the earliest Oligocene the northern Site 1172, a relatively warm-water cosmopolitan assemblage has been recovered. This aspect contrasts findings from coeval deposits from the Ross Sea, where endemic Antarctic species remain dominant. Somewhere between the paleogeographic positions of Site 1172 and the Ross Sea, a strong differentiation of surface waters occurred in the earliest Oligocene, possibly reflecting the onset of the Antarctic Circumpolar Current.