Chronostratigraphic framework for the IODP Expedition 318 cores from the Wilkes Land Margin: Constraints for paleoceanographic reconstruction-猫眼课题宝

DOI：

10.1029/2012pa002308

发表时间：

2012-06

期刊：

Paleoceanography

影响因子：

通讯作者：

中科院分区：

地学2区

文献类型：

作者：

L. Tauxe;C. Stickley;S. Sugisaki;P. Bijl;S. Bohaty;H. Brinkhuis;C. Escutia;J. Flores;A. Houben;M. Iwai;F. Jiménez-Espejo;R. McKay;S. Passchier;J. Pross;C. Riesselman;U. Röhl;F. Sangiorgi;K. Welsh;A. Klaus;Annick Fehr;J. Bendle;R. Dunbar;J. Gonzàlez;T. Hayden;K. Katsuki;M. Olney;S. Pekar;P. Shrivastava;T. Flierdt;T. Williams;M. Yamane

综合大洋钻探计划318航次在南极洲威尔克斯地边缘获取了一套从早始新世到全新世的沉积序列。良好的地层控制是了解关键气候区间内古海洋学事件发生时间的关键。钻探地点获取了始新世中下部、几乎整个渐新世、约1700万年前的中新世、整个上新世以及大部分更新世的地层。古地磁特性通常适合进行磁性地层学解释，退磁曲线表现良好，磁偏角分布均匀，并且清晰地分为两种磁倾角模式。尽管由于取芯原因，这些序列是不连续获取的，存在许多缺失，而且由于沉积和构造过程存在间断，但磁性地层模式通常很容易解释。我们的解释结合了硅藻、放射虫、钙质超微化石和沟鞭藻囊孢（沟鞭藻孢囊）生物地层学。磁性地层学显著提高了年代地层学的分辨率，特别是在生物地层学控制较差的区间。然而，具有可靠磁性地层学的南大洋记录明显稀少，这里报道的数据为改进生物地层学记录的校准提供了机会。特别是，我们为古近纪的沟鞭藻孢囊生物地层学提供了罕见的磁性地层学校准，并为上新世的硅藻校准提供了大幅改进。本文介绍了威尔克斯地边缘岩芯未来古海洋学替代指标记录的地层框架。它进一步对根据该地区地震勘测推断出的区域间断的持续时间提供了严格的限制。

The Integrated Ocean Drilling Program Expedition 318 to the Wilkes Land margin of Antarctica recovered a sedimentary succession ranging in age from lower Eocene to the Holocene. Excellent stratigraphic control is key to understanding the timing of paleoceanographic events through critical climate intervals. Drill sites recovered the lower and middle Eocene, nearly the entire Oligocene, the Miocene from about 17 Ma, the entire Pliocene and much of the Pleistocene. The paleomagnetic properties are generally suitable for magnetostratigraphic interpretation, with well-behaved demagnetization diagrams, uniform distribution of declinations, and a clear separation into two inclination modes. Although the sequences were discontinuously recovered with many gaps due to coring, and there are hiatuses from sedimentary and tectonic processes, the magnetostratigraphic patterns are in general readily interpretable. Our interpretations are integrated with the diatom, radiolarian, calcareous nannofossils and dinoflagellate cyst (dinocyst) biostratigraphy. The magnetostratigraphy significantly improves the resolution of the chronostratigraphy, particularly in intervals with poor biostratigraphic control. However, Southern Ocean records with reliable magnetostratigraphies are notably scarce, and the data reported here provide an opportunity for improved calibration of the biostratigraphic records. In particular, we provide a rare magnetostratigraphic calibration for dinocyst biostratigraphy in the Paleogene and a substantially improved diatom calibration for the Pliocene. This paper presents the stratigraphic framework for future paleoceanographic proxy records which are being developed for the Wilkes Land margin cores. It further provides tight constraints on the duration of regional hiatuses inferred from seismic surveys of the region.

Chronostratigraphic framework for the IODP Expedition 318 cores from the Wilkes Land Margin: Constraints for paleoceanographic reconstruction

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