Early diagenetic controls on color variation in Eocene red beds: a case study from the Gercus Formation, Zagros Basin, Kurdistan Region, Iraq

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

Early diagenetic controls on color variation in Eocene red beds: a case study from the Gercus Formation, Zagros Basin, Kurdistan Region, Iraq

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Early diagenetic controls on color variation in Eocene red beds: a case study from the Gercus Formation, Zagros Basin, Kurdistan Region, Iraq

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA22-15405S" target="_blank" >GA22-15405S: Raně diagenetická mobilita geochemických indikátorů redoxních podmínek a paleoklimatologický význam kontinentálních červených vrstev</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

JOURNAL OF SEDIMENTARY RESEARCH

ISSN

1527-1404

e-ISSN

1938-3681

Svazek periodika

95

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

24

Strana od-do

1032-1055

Kód UT WoS článku

001669698800002

EID výsledku v databázi Scopus

2-s2.0-105021064037