Detailed Information on Publication Record
2022
Ferruginous coated grains of microbial origin from the Lower Devonian (Pragian) of the Prague Basin (Czech Republic) – Petrological and geochemical perspective
VODRÁŽKOVÁ, Stanislava, Tomáš KUMPAN, Radek VODRÁŽKA, Jiří FRÝDA, Renata ČOPJAKOVÁ et. al.Basic information
Original name
Ferruginous coated grains of microbial origin from the Lower Devonian (Pragian) of the Prague Basin (Czech Republic) – Petrological and geochemical perspective
Authors
VODRÁŽKOVÁ, Stanislava (guarantor), Tomáš KUMPAN (203 Czech Republic, belonging to the institution), Radek VODRÁŽKA, Jiří FRÝDA, Renata ČOPJAKOVÁ (203 Czech Republic, belonging to the institution), Magdalena KOUBOVÁ, Axel MUNNECKE, Jiří KALVODA (203 Czech Republic, belonging to the institution) and Markéta HOLÁ (203 Czech Republic, belonging to the institution)
Edition
Sedimentary Geology, Amsterdam, Elsevier Science, 2022, 0037-0738
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10505 Geology
Country of publisher
Netherlands
Confidentiality degree
není předmětem státního či obchodního tajemství
References:
Impact factor
Impact factor: 2.800
RIV identification code
RIV/00216224:14310/22:00126714
Organization unit
Faculty of Science
UT WoS
000830322900001
Keywords in English
Ironstones; Microbialites; Trace elements geochemistry; REE geochemistry; Oncoids
Tags
Tags
International impact, Reviewed
Změněno: 20/9/2022 17:15, Mgr. Marie Šípková, DiS.
Abstract
V originále
A unique occurrence of ironstone lenses represented by ferruginous oncoids is reported from the offshore Iteporyje Limestone (Lower Devonian, Pragian) from the Prague Basin (the Stydle Vody Quarry). The oncoidal cortices show distinct arrangement of hematite/chamosite and/or iron-bearing calcite laminae, which are irregular, wavy and with a relatively high degree of inheritance of shape of the topography of the underlying laminae. Micro-domes and bulges, comparable to those observed in stromatolites and laminae overgrowing topographic irregularities represented by agglutinated foraminifers cemented to oncoid surfaces, were fairly commonly observed. The foraminifers probably represent the earliest representatives of agglutinated foraminifera encrusting surfaces of ferruginous grains. The surfaces of oncoids are wavy and often wrinkled. Although no microbial re-mains that could have been directly associated with oncoidal growth were recorded, we regard above mentioned features as indicators of biogenicity of the precipitates. We could only speculate the nature of the microbial consortia, but we regard the alternation of Fe2+ (chamosite, iron-bearing calcite) and Fe3+ (hematite) phases as a result of coupled oxidation -reduction processes related to passive and/or active microbial metabolic activities (precipitation of ferrihydrite - hematite precursor) and passive mineral authigenesis mediated by microorgan-isms (precipitation of chamosite precursor). Spatially restricted occurrence of the oncoidal lenses along with Al/Al + Fe + Mn vs. Fe/Ti, Nd vs. Ce/Ce*, Eu/Sm vs. Sm/Yb and other crossplots suggest that hydrothermal fluids were the most probable source of ferrous iron. Since most of the known oolitic or oncolitic ironstones represent rather large sedimentary bodies deposited around storm wave base to shallow subtidal environments under in-fluence of upwelled anoxic watermasses or continental runoff, the reported oncolitic mounds represent a specific example of ironstones formation.(C) 2022 Elsevier B.V. All rights reserved.
Links
GC20-20785J, research and development project |
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