NSFGEO-NERC: Developing A New Lower Cretaceous Time Scale: Foundation For The Next Generation Of Paleoceanographic And Biogeochemical Studies

NSFGEO-NERC：制定新的下白垩纪时间尺度：下一代古海洋学和生物地球化学研究的基础

• 批准号: NE/V019406/1
• 负责人: David Selby
• 金额: $ 17.56万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV019406%2F1
• 关键词: NSFGEO; NERC; Developing; New; Lower

During unusually warm greenhouse conditions of the Aptian to Cenomanian, several major perturbationsin the global carbon cycle are reflected by black shale deposits and/or carbon isotope excursions (OAEs).To fully understand the ocean-climate dynamics of this greenhouse world, and the mechanistic driversthat propel ocean anoxia and deterioration of ecosystems, new radioisotopic dating, in parallel with amore geographically dispersed array of high-quality Cretaceous sedimentary records are essential. TheYezo Group (YG), Japan comprises Aptian to Maastrichtian sediment deposited in a high latitude PacificOcean-facing fore arc basin. Unlike other well-studied Lower Cretaceous sequences, e.g., the VocontianBasin, France (VB), the YG contains rhyolitic tuffs amenable to precise U-Pb and 40Ar/39Ar dating. Wepropose to obtain new radioisotopic dates from the YG in concert with new osmium (Os) and carbon (C)isotope chemostratigraphy. This new chronology and chemostratigraphy can be exported and correlated torecords from Tethys, including the VB for which we aim to generate new Os and C isotopechemostratigraphy and an astrochronologic age model focused on the critical onset interval of OAE1a.Our proposed research to update and improve the Lower Cretaceous time scale by integrating French andJapanese strata is designed to rectify critical time scale inaccuracies, and employ refined time scales andnew proxy data to address fundamental questions concerning lithosphere-hydrosphere-biosphereinteractions associated with major Cretaceous C-cycle perturbations such as OAEs.

在阿普第阶至森诺曼阶异常温暖的温室条件下，黑色页岩沉积和/或碳同位素漂移（OAE）反映了全球碳循环中的几个重大扰动。为了充分了解这个温室世界的海洋气候动态，以及推动海洋缺氧和生态系统恶化的机械驱动因素，新的放射性同位素测年，与此同时，地理上更为分散高质量白垩纪沉积记录阵列也是必不可少的。日本的Yezo群（YG）由Aptian至Maastrichtian沉积物组成，沉积于高纬度面向太平洋的弧前盆地。与其他研究充分的下白垩纪层序不同，例如，法国VoccontianBasin（VB）的YG中含有流纹质凝灰岩，可进行精确的U-Pb和40 Ar/39 Ar定年。我们建议在新的锇（Os）和碳（C）同位素化学地层学的基础上，从YG获得新的放射性同位素年龄。这一新的年代学和化学地层学可以输出并与特提斯的记录相关联，包括我们旨在生成新的Os和C同位素化学地层学的VB和专注于OE 1a临界开始间隔的天体年代学年龄模型。我们提出的通过整合法国和日本地层来更新和改进下白垩纪时间尺度的研究旨在纠正临界时间尺度的不准确性，并采用改进的时间尺度和新的代理数据，以解决有关岩石圈水圈生物圈相互作用与主要的白垩纪C-循环扰动，如OAE的基本问题。