Early diagenetic controls on color variation in Eocene red beds: a case study from the Gercus Formation, Zagros Basin, Kurdistan Region, Iraq
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F25%3A73634455" target="_blank" >RIV/61989592:15310/25:73634455 - isvavai.cz</a>
Result on the web
<a href="https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/95/6/1032/661354/Early-diagenetic-controls-on-color-variation-in?redirectedFrom=fulltext" target="_blank" >https://pubs.geoscienceworld.org/sepm/jsedres/article-abstract/95/6/1032/661354/Early-diagenetic-controls-on-color-variation-in?redirectedFrom=fulltext</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.2110/jsr.2025.005" target="_blank" >10.2110/jsr.2025.005</a>
Alternative languages
Result language
angličtina
Original language name
Early diagenetic controls on color variation in Eocene red beds: a case study from the Gercus Formation, Zagros Basin, Kurdistan Region, Iraq
Original language description
This study investigates the mechanisms controlling the coloration of red beds of the Gercus Formation, which was deposited in a deltaic environment during the Eocene, and focusses on the dynamic interplay between depositional setting and diagenetic processes in shaping the distinct hues. A comprehensive multi-proxy methodology was employed, including facies analysis, quantitative color assessment using diffuse visible spectral reflectance (DRS), optical and electron microprobe microscopy, bulk-rock geochemistry (XRF and XRD), and in-situ geochemical analysis via laser-ablation ICP-MS. The results reveal that the spectrum of sediment hues, from red, to yellow-brown, gray-green, and gray, arise from the formation and distribution of Fe oxy/hydroxides, which are largely determined by sedimentary lithology, redox conditions, and diagenetic transformations. Sedimentation rates play a crucial role in regulating redox conditions and determining sediment coloration. Rapid sedimentation restricts oxygen exposure, fostering suboxic conditions that inhibit Fe oxidation, leading to gray-green sediments. Conversely, slower sedimentation allows for prolonged oxygen exposure, facilitating formation of Fe oxy/hydroxide and hematite, and resulting in red and yellow-brown sediments. Chlorite clay minerals are pivotal in transporting and supplying the Fe necessary for Fe oxy/hydroxide formation. Their transformation to chlorite-smectite mobilizes Fe either predepositionally or during eodiagenesis. In oxic environments, enhanced smectitization releases more Fe, preserving Fe oxy/hydroxides and promoting development of red sediment. In contrast, anoxic conditions suppress smectitization, dissolve predepositional Fe oxy/hydroxides, and produce non-red layers. Additionally, sediments with low clay content are unable to develop red coloration, even under oxic conditions, due to insufficient clay-mediated hematite formation, thereby retaining their original hues.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
<a href="/en/project/GA22-15405S" target="_blank" >GA22-15405S: Early diagenetic cycling of redox-sensitive geochemical proxies and palaeoclimatologic significance of continental red beds</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
JOURNAL OF SEDIMENTARY RESEARCH
ISSN
1527-1404
e-ISSN
1938-3681
Volume of the periodical
95
Issue of the periodical within the volume
6
Country of publishing house
US - UNITED STATES
Number of pages
24
Pages from-to
1032-1055
UT code for WoS article
001669698800002
EID of the result in the Scopus database
2-s2.0-105021064037