微量元素、生物标志物和粘土矿物学的化学地层特征表明了OAE 1a爆发前西班牙东北部奥加尼阿盆地阿普特阶沉积物中的环境条件

IF 1.9 3区 地球科学 Q1 GEOLOGY
Carlos Herdocia, Florentin J-M. R. Maurrasse
{"title":"微量元素、生物标志物和粘土矿物学的化学地层特征表明了OAE 1a爆发前西班牙东北部奥加尼阿盆地阿普特阶沉积物中的环境条件","authors":"Carlos Herdocia,&nbsp;Florentin J-M. R. Maurrasse","doi":"10.1002/dep2.186","DOIUrl":null,"url":null,"abstract":"<p>Shifting palaeoceanographic and palaeoclimatic conditions together with fluctuating eustatic sea levels during the Early Cretaceous Aptian stage led to a globally widespread deposition of organic-rich marine sediments designated Oceanic Anoxic Event 1a. Here a detailed lithostratigraphic and geochemical study is presented for 35.6 m of the Cabó Formation, part of the Organyà Basin, North-east Spain, to assess intermittent periods of enhanced organic carbon preservation in Lower Aptian sediments preceding Oceanic Anoxic Event 1a. The Organyà area contains well-exposed outcrops of Mesozoic black to dark grey marlstones and limestones with variable amount of organic matter (OM) indicative of oxygen-deficient conditions. Previous work in a section near the town of Organyà focussed on lithostratigraphy and biostratigraphy and assigned a Barremian–Aptian age. This study aims to provide an updated age based on carbon isotope correlation established elsewhere, and assess the chemostratigraphic characteristics of the Barremian–Aptian to clarify environmental changes regarding oxygen deficient conditions in the basin at that time. The δ<sup>13</sup>C<sub>org</sub> values fluctuate from −22.1 to −24.4‰ showing concurrence with results at the El Pui section west of the studied section. Chemostratigraphic correlation of the δ<sup>13</sup>C<sub>org</sub> reveals that the section is within segment C2, in the Lower Aptian. Redox-sensitive trace elements (V, Ni, Co, Cr, Cu, Mo) indicate heightened dysoxic conditions at five organic-rich layers, here designated carbonaceous layers (TOC &gt;2%), associated with enhanced terrigenous fluxes coincident with increased major elements (Al, Si and Ti) during these intervals. Biomarkers from six levels showed <i>n</i>-alkane distributions with chain lengths from <i>n</i>C<sub>14</sub> to <i>n</i>C<sub>34</sub>, mostly below <i>n</i>C<sub>21</sub> indicating a predominance of marine-derived OM. Climate conditions inferred from variable smectite, and kaolinite content suggests fluctuating humid-warm conditions. The results thus reveal that the Organyà Basin experienced intervals of distinct oxygen-poor conditions prior to the onset of Oceanic Anoxic Event 1a.</p>","PeriodicalId":54144,"journal":{"name":"Depositional Record","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.186","citationCount":"1","resultStr":"{\"title\":\"Chemostratigraphic characteristics of trace elements, biomarkers and clay mineralogy indicating environmental conditions within Aptian sediments of the Organyà Basin, North-east Spain, prior to the onset of OAE 1a\",\"authors\":\"Carlos Herdocia,&nbsp;Florentin J-M. R. Maurrasse\",\"doi\":\"10.1002/dep2.186\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Shifting palaeoceanographic and palaeoclimatic conditions together with fluctuating eustatic sea levels during the Early Cretaceous Aptian stage led to a globally widespread deposition of organic-rich marine sediments designated Oceanic Anoxic Event 1a. Here a detailed lithostratigraphic and geochemical study is presented for 35.6 m of the Cabó Formation, part of the Organyà Basin, North-east Spain, to assess intermittent periods of enhanced organic carbon preservation in Lower Aptian sediments preceding Oceanic Anoxic Event 1a. The Organyà area contains well-exposed outcrops of Mesozoic black to dark grey marlstones and limestones with variable amount of organic matter (OM) indicative of oxygen-deficient conditions. Previous work in a section near the town of Organyà focussed on lithostratigraphy and biostratigraphy and assigned a Barremian–Aptian age. This study aims to provide an updated age based on carbon isotope correlation established elsewhere, and assess the chemostratigraphic characteristics of the Barremian–Aptian to clarify environmental changes regarding oxygen deficient conditions in the basin at that time. The δ<sup>13</sup>C<sub>org</sub> values fluctuate from −22.1 to −24.4‰ showing concurrence with results at the El Pui section west of the studied section. Chemostratigraphic correlation of the δ<sup>13</sup>C<sub>org</sub> reveals that the section is within segment C2, in the Lower Aptian. Redox-sensitive trace elements (V, Ni, Co, Cr, Cu, Mo) indicate heightened dysoxic conditions at five organic-rich layers, here designated carbonaceous layers (TOC &gt;2%), associated with enhanced terrigenous fluxes coincident with increased major elements (Al, Si and Ti) during these intervals. Biomarkers from six levels showed <i>n</i>-alkane distributions with chain lengths from <i>n</i>C<sub>14</sub> to <i>n</i>C<sub>34</sub>, mostly below <i>n</i>C<sub>21</sub> indicating a predominance of marine-derived OM. Climate conditions inferred from variable smectite, and kaolinite content suggests fluctuating humid-warm conditions. The results thus reveal that the Organyà Basin experienced intervals of distinct oxygen-poor conditions prior to the onset of Oceanic Anoxic Event 1a.</p>\",\"PeriodicalId\":54144,\"journal\":{\"name\":\"Depositional Record\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.9000,\"publicationDate\":\"2022-03-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/dep2.186\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Depositional Record\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/dep2.186\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Depositional Record","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/dep2.186","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 1

摘要

早白垩世Aptian时期古海洋学和古气候条件的变化以及海平面的波动导致了全球范围内富有机海洋沉积物的沉积,被称为海洋缺氧事件1a。本文对西班牙东北部organy盆地Cabó组35.6 m的地层进行了详细的岩石地层学和地球化学研究,以评估海洋缺氧事件1a之前下Aptian沉积物中有机碳保存增强的间歇期。有机质区发育出露良好的中生代黑色至深灰色泥灰岩和灰岩,有机质含量变化,显示出缺氧条件。以前在organyo镇附近的一个地区的工作主要集中在岩石地层学和生物地层学上,并确定了巴雷米亚-阿普提亚时代。本研究旨在基于其他地区建立的碳同位素对比提供一个更新的时代,并评估巴雷米亚—阿普田的化学地层特征,以澄清当时盆地缺氧条件的环境变化。δ13Corg值在- 22.1 ~ - 24.4‰之间波动,与研究剖面以西El Pui剖面的结果一致。δ13Corg化学地层对比表明,该剖面位于下阿普天统C2段。氧化还原敏感微量元素(V、Ni、Co、Cr、Cu、Mo)表明,在5个富有机质层(这里指定为碳质层(TOC含量为2%))中,氧化还原敏感微量元素(V、Ni、Co、Cr、Cu、Mo)的缺氧条件加剧,在这些区间内,陆源通量增强,主要元素(Al、Si和Ti)增加。6个水平的生物标志物显示,正构烷烃链长分布在nC14 - nC34之间,大部分低于nC21,表明海洋来源的OM占主导地位。从蒙脱石和高岭石含量的变化推断出的气候条件表明湿热条件的波动。结果表明,在海洋缺氧事件1a发生之前,有机盆地经历了不同的缺氧条件。
本文章由计算机程序翻译,如有差异,请以英文原文为准。

Chemostratigraphic characteristics of trace elements, biomarkers and clay mineralogy indicating environmental conditions within Aptian sediments of the Organyà Basin, North-east Spain, prior to the onset of OAE 1a

Chemostratigraphic characteristics of trace elements, biomarkers and clay mineralogy indicating environmental conditions within Aptian sediments of the Organyà Basin, North-east Spain, prior to the onset of OAE 1a

Shifting palaeoceanographic and palaeoclimatic conditions together with fluctuating eustatic sea levels during the Early Cretaceous Aptian stage led to a globally widespread deposition of organic-rich marine sediments designated Oceanic Anoxic Event 1a. Here a detailed lithostratigraphic and geochemical study is presented for 35.6 m of the Cabó Formation, part of the Organyà Basin, North-east Spain, to assess intermittent periods of enhanced organic carbon preservation in Lower Aptian sediments preceding Oceanic Anoxic Event 1a. The Organyà area contains well-exposed outcrops of Mesozoic black to dark grey marlstones and limestones with variable amount of organic matter (OM) indicative of oxygen-deficient conditions. Previous work in a section near the town of Organyà focussed on lithostratigraphy and biostratigraphy and assigned a Barremian–Aptian age. This study aims to provide an updated age based on carbon isotope correlation established elsewhere, and assess the chemostratigraphic characteristics of the Barremian–Aptian to clarify environmental changes regarding oxygen deficient conditions in the basin at that time. The δ13Corg values fluctuate from −22.1 to −24.4‰ showing concurrence with results at the El Pui section west of the studied section. Chemostratigraphic correlation of the δ13Corg reveals that the section is within segment C2, in the Lower Aptian. Redox-sensitive trace elements (V, Ni, Co, Cr, Cu, Mo) indicate heightened dysoxic conditions at five organic-rich layers, here designated carbonaceous layers (TOC >2%), associated with enhanced terrigenous fluxes coincident with increased major elements (Al, Si and Ti) during these intervals. Biomarkers from six levels showed n-alkane distributions with chain lengths from nC14 to nC34, mostly below nC21 indicating a predominance of marine-derived OM. Climate conditions inferred from variable smectite, and kaolinite content suggests fluctuating humid-warm conditions. The results thus reveal that the Organyà Basin experienced intervals of distinct oxygen-poor conditions prior to the onset of Oceanic Anoxic Event 1a.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
CiteScore
4.10
自引率
16.70%
发文量
42
审稿时长
16 weeks
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信