沙特阿拉伯国家石油公司Soua Mohamed研究团队报道，使用元素化学地层学方法首次记录了鲁卜哈利盆地东部Cenomanian-Turonian海洋缺氧事件(OAE-2)。该项研究成果发表在2024年9月17日出版的《地球化学学报》上。

据研究人员介绍，阿拉伯东部的许多地点都含有富有机质的Cenomanian-Turonian(C/T)沉积物，包括卡塔尔、阿联酋和阿曼。本研究涉及富有机质相与贫有机质缺氧相的对比，以及C/T相的局部到区域分布。

钻孔数据显示，这些区域被证实富含有机物质，研究人员精确地确定了它们的极限。无机地球化学研究主要集中在Wasia组上部的Cenomanian-Turonian期Mishrif段。在油气勘探和开发阶段，这种元素化学地层学方法被认为是一种及时、经济的碳同位素测定方法。该研究揭示了大陆架内盆地古海洋学在Cenomanian-Turonian时期如何变化的信息。

离散氧化还原敏感性和初级生产力以及敏感的微量元素数据和碎屑相关元素，被证明是凸显该地区在OAE-2期间占统治地位的还原条件的最佳方法之一。

氧化还原敏感指标显示，在Cenomanian-Turonian期Mishrif组，与底水相关的缺氧到滞流条件有三个宽脉冲，由贫氧到常氧条件分开。盆地的几何形状或最小含氧带(OMZ)的扩张，是控制Mishrif组沉积过程中底部氧化还原条件分布的主要因素。在缺乏碳同位素扰动数据的情况下，元素化学地层学已被用于研究区域的OAE-2相的识别和表征。

附：英文原文

Title: First record of the Cenomanian-Turonian Oceanic Anoxic Event (OAE-2) in the eastern Rub’ Al Khali Basin by means of elemental chemostratigraphy

Author: Soua, Mohamed, Scheibe, Christian, Craigie, Neil

Issue&Volume: 2024-09-17

Abstract: Numerous locations in Eastern Arabia contain organic-rich Cenomanian-Turonian (C/T) sediments, including Qatar, UAE, and Oman. The contrast between organic-rich and organic-lean anoxic facies, as well as the local to regional distribution of the C/T facies, is shown here. These regions are confirmed to be rich in organic material using bore-hole data, and our study has precisely identified their limits. The inorganic geochemical investigations focus on the Cenomanian-Turonian Mishrif Member of the upper Wasia Formation. This elemental chemostratigraphy approach is investigated as a timely and cost-effective substitution for carbon isotope determination during hydrocarbon exploration and development phases. The study reveals information about how the palaeoceanography of intrashelf basin changed throughout the Cenomanian-Turonian time. The use of discrete redox-sensitive and primary productivity along with sensitive trace element data and detrital-related elements is demonstrated as one of the best methods to emphasise the reducing conditions that reigned during the OAE-2 in the area. The redox-sensitive proxies show three broad pulses of anoxic to euxinic conditions associated with the bottom water, separated by dysoxic to oxic conditions in the Cenomanian-Turonian Mishrif Member. Either the basin geometry or the expansion of an oxygen minimum zone (OMZ) is the main factor that controlled the bottom redox condition distribution during the deposition of the Mishrif Member. Elemental chemostratigraphy has been utilised to identify and characterise the OAE-2 phases in the study area in the absence of carbon isotope perturbation data.

DOI: 10.1007/s11631-024-00734-x

Source: https://link.springer.com/article/10.1007/s11631-024-00734-x