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。我们推测，位于C3An.2n、C3.Ar和C30n磁控管中的晚中新世地中海剖面(Sorbas、Faneromei、Messadit等)的火山灰层调谐存在2-3个进动旋回(40-60KYR)的不正确。为了验证这一假设，我们正在利用地中海以外的三个ODPIODP站点(926、U1337、U1338)，开发一个非常准确的、经过天文校准的晚中新世磁极克莱恩斯C3An.1n(6 MA)到C4n.1n(7.5 mA)(包括C3An.2n、C3.Ar和C30n)的时间刻度。在该项目的第一阶段，对在U1337站点获得的新的磁层数据进行了初步解释，从而确定了14个地磁反转，其中8个反转位置的置信度非常高。其余6个逆转头寸，包括Chron C30亿，仍需要进一步分析。到目前为止分析的稳定同位素地层学样品中含有足够的海底有孔虫，以产生适合天文调谐的同位素记录。这项延期建议的主要目标是准确定位6个关键反转的位置，延长U1337站点的高分辨率海底稳定同位素记录，并填补ODP982和1264站点同位素记录中的空白。所有记录将被整合，以产生5.2-8.2 Ma之间的高分辨率、天文调谐的海底稳定氧同位素堆栈，以提供托尔顿纪晚期和梅西期的全球地层参考剖面。以设想的海底稳定氧和碳同位素记录为基础的高分辨率古海洋学重建将能够解决悬而未决的晚中新世古气候问题。在根据我们的新数据进行古海洋重建的同时，需要进行调查，评估次生成岩蚀变对初级海底同位素信号的影响，以及分析和自然样品的可变性。

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