Mineral phases and growth conditions of morphologically diverse shelfal ferromanganese concretions

IF 4.5 1区 地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS
Joonas Wasiljeff, Changxun Yu, Pasi Heikkilä, Yann Lahaye, Matti Kurhila, Wei‐Li Hong, Aivo Lepland, Sten Suuroja, Volker Liebetrau, Joonas J. Virtasalo
{"title":"Mineral phases and growth conditions of morphologically diverse shelfal ferromanganese concretions","authors":"Joonas Wasiljeff, Changxun Yu, Pasi Heikkilä, Yann Lahaye, Matti Kurhila, Wei‐Li Hong, Aivo Lepland, Sten Suuroja, Volker Liebetrau, Joonas J. Virtasalo","doi":"10.1016/j.gca.2025.05.012","DOIUrl":null,"url":null,"abstract":"Ferromanganese concretions in the shelf sea regions, such as the Baltic Sea, are of significant interest due to their geochemical properties, economic resource potential, and roles in benthic ecosystems. This study analyses the authigenic and detrital mineral phases and their provenance in the Baltic Sea concretions, as well as their formation mechanisms and diagenetic evolution. These concretions exist in three distinct morphotypes: crust, discoidal, and spheroidal. Using synchrotron-based techniques (µ-XRF and µ-XAS) paired with XRD, stable Pb isotope, and bulk geochemical analyses, we found that discoidal and spheroidal concretions consist of alternating Fe- and Mn-rich layers, whereas crust concretions are predominantly Fe-rich. The Mn phases primarily consist of birnessite-like phyllomanganates with columnar and branched dendritic growth patterns, indicative of microbially-mediated precipitation. In contrast, the Fe phases are represented by poorly crystalline ferrihydrite, the formation of which is influenced by admixing of detrital minerals. The three main components (Fe-rich, Mn-rich and detrital), each exhibit distinct trace element associations. The geochemical composition and morphology of the Baltic Sea concretions resembles other shelfal precipitates, indicating consistency in formation mechanisms across different shelf environments. Slightly negative to intermediate Ce anomaly values and the range in Nd contents in the samples suggest that early diagenetic processes contribute to the formation of all the morphotypes.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"34 1","pages":""},"PeriodicalIF":4.5000,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geochimica et Cosmochimica Acta","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1016/j.gca.2025.05.012","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

Ferromanganese concretions in the shelf sea regions, such as the Baltic Sea, are of significant interest due to their geochemical properties, economic resource potential, and roles in benthic ecosystems. This study analyses the authigenic and detrital mineral phases and their provenance in the Baltic Sea concretions, as well as their formation mechanisms and diagenetic evolution. These concretions exist in three distinct morphotypes: crust, discoidal, and spheroidal. Using synchrotron-based techniques (µ-XRF and µ-XAS) paired with XRD, stable Pb isotope, and bulk geochemical analyses, we found that discoidal and spheroidal concretions consist of alternating Fe- and Mn-rich layers, whereas crust concretions are predominantly Fe-rich. The Mn phases primarily consist of birnessite-like phyllomanganates with columnar and branched dendritic growth patterns, indicative of microbially-mediated precipitation. In contrast, the Fe phases are represented by poorly crystalline ferrihydrite, the formation of which is influenced by admixing of detrital minerals. The three main components (Fe-rich, Mn-rich and detrital), each exhibit distinct trace element associations. The geochemical composition and morphology of the Baltic Sea concretions resembles other shelfal precipitates, indicating consistency in formation mechanisms across different shelf environments. Slightly negative to intermediate Ce anomaly values and the range in Nd contents in the samples suggest that early diagenetic processes contribute to the formation of all the morphotypes.
不同形态铁锰结块的矿物相及生长条件
由于其地球化学性质、经济资源潜力和在底栖生态系统中的作用,波罗的海等陆架海域的锰铁结块引起了人们的极大兴趣。本文分析了波罗的海结核中自生和碎屑矿物相及其物源,以及它们的形成机制和成岩演化。这些结块以三种不同的形态存在:地壳状、盘状和球状。利用同步加速器技术(µ- xrf和µ- xas)与XRD、稳定Pb同位素和大量地球化学分析相结合,我们发现盘状和球状结核由富铁层和富锰层交替组成,而地壳结核则以富铁层为主。Mn相主要由像碧玉一样的叶锰酸盐组成,具有柱状和分枝状的枝晶生长模式,表明微生物介导的沉淀。相比之下,铁相以结晶度差的水合铁为代表,其形成受碎屑矿物混合的影响。三种主要成分(富铁、富锰和碎屑)均表现出不同的微量元素关联。波罗的海凝块的地球化学组成和形态与其他陆架沉积物相似,表明不同陆架环境下形成机制的一致性。样品中Ce值略负至中等的异常值和Nd含量的变化范围表明,早期成岩作用有助于所有形态型的形成。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Geochimica et Cosmochimica Acta
Geochimica et Cosmochimica Acta 地学-地球化学与地球物理
CiteScore
9.60
自引率
14.00%
发文量
437
审稿时长
6 months
期刊介绍: Geochimica et Cosmochimica Acta publishes research papers in a wide range of subjects in terrestrial geochemistry, meteoritics, and planetary geochemistry. The scope of the journal includes: 1). Physical chemistry of gases, aqueous solutions, glasses, and crystalline solids 2). Igneous and metamorphic petrology 3). Chemical processes in the atmosphere, hydrosphere, biosphere, and lithosphere of the Earth 4). Organic geochemistry 5). Isotope geochemistry 6). Meteoritics and meteorite impacts 7). Lunar science; and 8). Planetary geochemistry.
×
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