Time Scale Controversy: accurate orbital calibration of the late Miocene

时标争议：中新世晚期的精确轨道校准

• 批准号: 242225091
• 负责人: Dr. Thomas Westerhold
• 金额: --
• 依托单位: College of Earth, Ocean, and Atmospheric Sciences
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/242225091?language=en
• 关键词: Time; Scale; Controversy; accurate; orbital

The objective of the project is to investigate potential intrinsic problems with the rock clock synchronization between radio-isotopic and astronomic dating techniques. We hypothesize that the tuning of ash layers in the late Miocene Mediterranean sections (Sorbas, Faneromeni, Messadit, etc.; located in magnetochrons C3An.2n, C3.Ar and C3Bn) used for the synchronization is incorrect by 2-3 precession cycles (40-60 kyr). To test this hypothesis, we are developing a very accurate, astronomically calibrated late Miocene time scale for magnetic polarity Chrons C3An.1n (6 Ma) to C4n.1n (7.5 Ma) (including C3An.2n, C3.Ar and C3Bn) using three ODP/IODP sites outside the Mediterranean (926, U1337, U1338). During the first phase of the project, preliminary interpretation of new magnetostratigraphic data acquired at Site U1337 allowed identification of fourteen geomagnetic reversals, of which eight reversal positions have been located with very high confidence. The remaining six reversal positions, including Chron C3Bn, still need further analyses. The samples for the stable isotope stratigraphy analyzed so far contain sufficient benthic foraminifera to generate an isotopic record suitable for astronomical tuning. The main goal of this extension proposal is to exactly pinpoint the position of six key reversals and extend the high-resolution benthic stable isotope record at Site U1337, and fill gaps located in isotope records from ODP Sites 982 and 1264. All records will be integrated to generate a high-resolution, astronomically tuned benthic stable oxygen isotope stack between 5.2-8.2 Ma to provide a global stratigraphic reference section for the late Tortonian and Messinian. High-resolution paleoceanographical reconstructions based on the envisaged benthic stable oxygen and carbon isotope records will allow resolving of outstanding late Miocene paleoclimate questions. The paleoceanographic reconstructions based on our new data need to be accompanied by investigations evaluating how the primary benthic isotope signal is affected by secondary diagenetic alterations, and analytical and natural sample variability.

该项目的目标是调查放射性同位素和天文测年技术之间岩石时钟同步的潜在内在问题。我们假设用于同步的中新世晚期地中海剖面（Sorbas、Faneromeni、Messadit 等；位于磁同步器 C3An.2n、C3.Ar 和 C3Bn）中灰层的调谐不正确，误差为 2-3 个进动周期（ 40-60 基里尔）。为了检验这一假设，我们正在开发一个非常精确、经天文校准的中新世晚期磁极时间尺度 Chrons C3An.1n (6 Ma) 至 C4n.1n (7.5 Ma)（包括 C3An.2n、C3.Ar 和 C3Bn），使用地中海以外的三个 ODP/IODP 站点（926、U1337、U1338）。在该项目的第一阶段，对在 U1337 站点获取的新磁地层数据进行初步解释，确定了 14 个地磁反转，其中 8 个反转位置的定位可信度非常高。包括 Chron C3Bn 在内的其余 6 个反转位置仍需要进一步分析。迄今为止分析的稳定同位素地层学样本包含足够的底栖有孔虫以生成适合天文调谐的同位素记录。该扩展提案的主要目标是精确定位六个关键逆转的位置，扩展 U1337 站点的高分辨率底栖稳定同位素记录，并填补 ODP 982 和 1264 站点同位素记录中的空白。所有记录都将被整合生成 5.2-8.2 Ma 之间的高分辨率、天文学调谐的底栖稳定氧同位素堆栈，为晚期提供全球地层参考部分托尔托尼安和麦西尼安。基于设想的海底稳定氧和碳同位素记录的高分辨率古海洋学重建将能够解决悬而未决的中新世晚期古气候问题。基于我们的新数据的古海洋学重建需要伴随着评估主要底栖同位素信号如何受到次生成岩变化以及分析和自然样本变异性影响的研究。

项目成果

Revisiting the Ceara Rise, equatorial Atlantic Ocean: isotope stratigraphy of ODP Leg 154 from 0 to 5 Ma

重访赤道大西洋塞阿拉隆起：ODP Leg 154 0 至 5 Ma 的同位素地层学

• DOI: 10.5194/cp-13-779-2017
• 发表时间: 2017
• 期刊: Climate of The Past
• 影响因子: 4.3
• 作者: Wilkens;Westerhold;Gorgas
• 通讯作者: Gorgas

International Ocean Discovery Program Expedition 363 Preliminary Report Western Pacific Warm Pool Neogene and Quaternary records of Western Pacific Warm Pool paleoceanography

• DOI: 10.14379/iodp.pr.363.2017
• 发表时间: 2017-02
• 作者: Y. Rosenthal;A. Holbourn;D. Kulhanek;I. Aiello;T. Babila;G. Bayon;L. Beaufort;S. C. Bova;J.-H. Chun;H. Dang;A. Drury;T. Jones;P. Eichler;A.G.S. Fernando;K. Gibson;R. Hatfield;Dan M. Johnson;Y. Kumagai;B. Linsley;N. Meinicke;G. Mountain;B. Opdyke;P. Pearson;C. R. Poole;A. Ravelo;T. Sagawa;A. Schmitt;J. B. Wurtzel;Jian Xu;Masanobu Yamamoto;Yi Zhang