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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:35 |
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Conference: Bucharest University Faculty of Physics 2024 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Assessment of redox condition in sediments using pyrite morphological features: a preliminary investigation using SEM-EDS
Authors:
Daniel STOICESCU(1,2), Alfred VESPREMEANU-STROE(3), Luminita PREOTEASA(4)
*
Affiliation:
1)University of Bucharest, Faculty of Physics, Doctoral School on Physics, 405 Atomiștilor, 077125 Măgurele, Romania
2)University of Bucharest, ArchaeoSciences Division–ICUB, 90 Panduri Str. 050663 Bucharest, Romania
3)University of Bucharest, Faculty of Geography, 1 N. Balcescu blv., 010041 Bucharest, Romania
4)Sfântu Gheorghe Marine and Fluvial Research Station, University of Bucharest, Faculty of Geography, Sf. Gheorghe, Tulcea, Romania
E-mail
daniel.stoicescu18@gmail.com
Keywords:
sediments, pyrite, SEM-EDS, framboids
Abstract:
Framdoidal pyrite is one of the most intriguing types of textural features, its occurrence being noted in sediments from all geological time frames. Hence, its morphological features became, together with other proxies, a well-established method to derive paleo-redox conditions in marine or lacustrine environments. The present study presents a preliminary analysis performed through scanning electron microscopy coupled with an energy-dispersive spectrometry detection system. The current analyses were performed on a batch of 5 samples derived from a Balea lake sediment core, which were priorly geochemically examined with a Cox Itrax sediment core scanner. Two of the currently investigated samples, corresponding to depths where peaks of S and Fe concentrations were identified have shown the presence of pyrite framboids. Measurements performed on the BSE images show that the framboids have an average value situated between 16 and 18 μm with a standard deviation between 3 and 6 microns, thus suggesting the presence of an oxic-dysoxic environment. Despite the preliminary character and the need for more data for a better assessment of the pyrite occurrence in sedimentary structures, the present analysis is well supported by other findings of framboids presenting similar morphological features reported in the literature.
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