Trace Elements in Carbonates: Isotopic and Geochronological Record

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Mineral Geochemistry and Geochronology".

Deadline for manuscript submissions: closed (30 November 2020) | Viewed by 6508

Special Issue Editors


E-Mail Website
Guest Editor
School of Geosciences, University of Witwatersrand, Johannesburg, South Africa

E-Mail Website
Guest Editor
Division of Earth Science and Resource Engineering, CSIRO, The Commonwealth Scientific and Industrial Research Organisation
Interests: U-Pb and U-Th dating of carbonates (solution and LA); trace element and stable isotope geochemistry of carbonates; fault-related carbonates and speleothems

Special Issue Information

Dear Colleagues,

Carbonate rocks and minerals (calcite, dolomite, siderite, aragonite, magnesite being the most common) form in a variety of geological settings, over much of Earth’s history. Carbonates preserve geochemical and isotopic records of depositional environments and processes. Carbonates are also amenable to absolute dating, using the Pb-Pb, U-Pb and U-Th disequilibrium chronometers.

A particular powerful approach to the study of carbonate formation is linking textural observations, such as CL imaging, with in-situ micro-analytical methods, to unlock multi-stage mineral formation histories. Specifically, LA-ICPMS in-situ measurement allows retrieving geochemical and isotopic (both radiogenic and stable) information at the micro-metre scale. The combined measurement of major and trace element concentrations and isotopic ratios, when coupled to petrographic observations, can provide detailed insights into the timing of thermal and fluid-flow events of sedimentary basins and hydrothermal systems, also in association with fault movements. Since carbonates form as primary sedimentary rocks (marine, lacustrine, soils) and fluid-precipitates, the study of such rocks and minerals enables detailed study of hydrothermal-epithermal processes, precipitation in aquatic systems as well as the direct dating of deformation, fluid-flow and hydrology in crust, mineral deposits and diagenetic formation of cements.  Carbonate cave deposits, including flow-stones and speleothems, allow reconstruction of hominid evolution and past climates. Innovative research in carbonates using a multi-method and multi-element approach can also develop insights into the complex interplay of seismicity/continental deformation, climate, hydrology, volcanic activity and human evolution.

Prof. Dr. Robert Bolhar
Dr. Tonguc Uysal
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • climate
  • deformation
  • hydrology
  • geochronology
  • in-situ micro-analytical methods
  • environments and processes
  • hominid evolution
  • mineralization

Published Papers (2 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

19 pages, 5095 KiB  
Article
Deeply Buried Authigenic Carbonates in the Qiongdongnan Basin, South China Sea: Implications for Ancient Cold Seep Activities
by Jiangong Wei, Tingting Wu, Wei Zhang, Yinan Deng, Rui Xie, Junxi Feng, Jinqiang Liang, Peixin Lai, Jianhou Zhou and Jun Cao
Minerals 2020, 10(12), 1135; https://doi.org/10.3390/min10121135 - 17 Dec 2020
Cited by 21 | Viewed by 2894
Abstract
Cold seep carbonates are important archives of pore water chemistry and ancient methane seepage activity. They also provide an important contribution to the global carbon sink. Seep carbonates at three sediment layers (3.0, 52.1, and 53.6 mbsf) were collected at site W08B in [...] Read more.
Cold seep carbonates are important archives of pore water chemistry and ancient methane seepage activity. They also provide an important contribution to the global carbon sink. Seep carbonates at three sediment layers (3.0, 52.1, and 53.6 mbsf) were collected at site W08B in the Qiongdongnan Basin of the South China Sea. This study investigated the mineralogy, microstructure, stable carbon and oxygen isotopes, trace elements, and U-Th dates of these carbonates to identify the relationship between methane flux and authigenic carbonate precipitation. The results showed that the δ13C and δ18O values of all carbonates are similar, indicating that the carbon source for shallow carbonates and deep carbonates has remained constant over time and included biogenic and thermogenic methane. Although carbonates were found in three sediment layers, the two main stages of methane seepage events were discernible, which was likely caused by the dissociation of gas hydrates. The first methane seep took place at 131.1–136.3 ka BP. During a dramatic drop in the sea level, the seep carbonate at 52.1 mbsf formed at 136.3 ka BP through the anaerobic oxidation of methane (AOM). The carbonate at 53.6 mbsf resulted from the vertical downward movement of the sulfate-methane transition zone with decreasing methane flux at 131.1 ka BP. This is the reason for the age of carbonates at 52.1 mbsf being older than the age of carbonates at 53.6 mbsf. The second methane seep took place at 12.2 ka BP. Shallow carbonate formed at that time via AOM and is now located at 3 mbsf. Moreover, thin-section photomicrographs of deep carbonate mainly consisted of matrix micrite and biological debris and acicular aragonite occurred as vein cement filling the pore spaces between the matrix micrite. The acicular aragonite was mainly influenced by the timing of the carbonate precipitation of minerals. This research identified a long history of methane seep activity reflected by the vertical distribution of carbonates. Full article
(This article belongs to the Special Issue Trace Elements in Carbonates: Isotopic and Geochronological Record)
Show Figures

Figure 1

12 pages, 3864 KiB  
Article
Element Patterns of Primary Low-Magnesium Calcite from the Seafloor of the Gulf of Mexico
by Huiwen Huang, Xudong Wang, Shanggui Gong, Nicola Krake, Daniel Birgel, Jörn Peckmann, Duofu Chen and Dong Feng
Minerals 2020, 10(4), 299; https://doi.org/10.3390/min10040299 - 27 Mar 2020
Cited by 2 | Viewed by 2819
Abstract
High-magnesium calcite (HMC) and aragonite are metastable minerals, which tend to convert into low-magnesium calcite (LMC) and dolomite. During this process, primary compositions are frequently altered, resulting in the loss of information regarding the formation environment and the nature of fluids from which [...] Read more.
High-magnesium calcite (HMC) and aragonite are metastable minerals, which tend to convert into low-magnesium calcite (LMC) and dolomite. During this process, primary compositions are frequently altered, resulting in the loss of information regarding the formation environment and the nature of fluids from which the minerals precipitated. Petrological characteristics have been used to recognize primary LMC, however, neither the element distribution within primary LMC nor the effect of diagenetic alteration on element composition have been studied in detail. Here, two mostly authigenic carbonate lithologies from the northern Gulf of Mexico dominated by primary LMC were investigated to distinguish element compositions of primary LMC from LMC resulting from diagenetic alteration. Primary LMC reveals similar or lower Sr/Ca ratios than primary HMC. The lack of covariation between Sr/Ca ratios and Mg/Ca ratios in the studied primary LMCs are unlike compositions observed for LMC resulting from diagenetic alteration. The Sr/Mn ratios and Mn contents of the primary LMCs are negatively correlated, similar to secondary, diagenetic LMC. Element mapping for Sr and Mg in the primary LMC lithologies revealed no evidence of conversion from aragonite or HMC to LMC, and a homogenous distribution of Mn is in accordance with the absence of late diagenetic alteration. Our results confirm that Sr/Ca ratios, Mg/Ca ratios, and element systematics of primary LMC are indeed distinguishable from diagenetically altered carbonates, enabling the utilization of element geochemistry in recognizing primary signals in carbonate archives. Full article
(This article belongs to the Special Issue Trace Elements in Carbonates: Isotopic and Geochronological Record)
Show Figures

Figure 1

Back to TopTop