2018
Fine-scale LA-ICP-MS study of redox oscillations and REEY cycling during the latest Devonian Hangenberg Crisis (Moravian Karst, Czech Republic)
KALVODA, Jiří, Tomáš KUMPAN, Markéta HOLÁ, Ondřej BÁBEK, Viktor KANICKÝ et. al.Základní údaje
Originální název
Fine-scale LA-ICP-MS study of redox oscillations and REEY cycling during the latest Devonian Hangenberg Crisis (Moravian Karst, Czech Republic)
Autoři
KALVODA, Jiří (203 Česká republika, garant, domácí), Tomáš KUMPAN (203 Česká republika, domácí), Markéta HOLÁ (203 Česká republika, domácí), Ondřej BÁBEK (203 Česká republika), Viktor KANICKÝ (203 Česká republika, domácí) a Radek ŠKODA (203 Česká republika, domácí)
Vydání
Palaeogeography, Palaeoclimatology, Palaeoecology, Elsevier, 2018, 0031-0182
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10500 1.5. Earth and related environmental sciences
Stát vydavatele
Nizozemské království
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 2.616
Kód RIV
RIV/00216224:14310/18:00100887
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000425071100004
Klíčová slova anglicky
Trace elements;REE;Devonian-Carboniferous boundary;Microbialites;Anachronistic facies
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 11. 4. 2018 16:33, Mgr. Tomáš Kumpan, Ph.D.
Anotace
V originále
Trace elements and REEY distribution of thinly laminated limestone (laminite) and underlying pre-event calciturbidite (Siphonodella praesulcata conodont Zone) deposited in association with the Hangenberg Black Shale Event were analyzed using laser ablation-inductively coupled plasma-mass spectrometry. These deposits were also analyzed by carbonate petrography and scanning electron microscopy. Our study documents the origin of authigenic microbial limestones during the latest Devonian Hangenberg extinction event, when unusual oceanic conditions appear to have enhanced precipitation of calcite within microbial carbonates. Detrital contamination of the calciturbidite and laminated limestone is very low, as demonstrated by low contents of Al, Zr, Ti and Th. These deposits display only limited degree of early diagenetic overprint of limestones, and some of them fall within or very close to the seawater field. Elevated U and Mo enrichments and covariation patterns reflect the episodic establishment of oxic to euxinic bottom condition during deposition of the laminite. The oxic conditions that existed during accumulation of the underlying calciturbidite were likely the result of turbidity current introduction of oxygen into the bottom environment. REE contents of both the laminite and calciturbidite are nearly ten times higher than those of most modern carbonates and similar to Devonian microbialites from the Canning Basin. Calciturbidite display a prominent MREEN bulge. Shale-normalized REE patterns of the overlying laminite are similar to those of modern seawater and Devonian microbialites from the Canning Basin (LREE depletion and progressive enrichments in heavier REE) reflecting the dominance of authigenic carbonate phases. Minor contamination is bound to apatites, siliciclastic minerals, pyrites and organic matter. The element content of authigenic phases benefited from Fe and Mn oxyhydroxide redox cycling. Negative Ce and positive Eu anomalies, low Y/Ho ratios, and very low Al/(Al + Fe + Mn) ratios suggest an influence of diluted high- temperature hydrothermal fluids perhaps related to latest Devonian rift magmatism in the eastern part of the Rhenohercynian zone. The proliferation of anachronistic facies following the Devonian-Carboniferous (D-C) extinction event recognized in Moravia and traced worldwide seems to share some features in common with anachronistic carbonate sequences documented in the aftermath of the end-Permian mass extinction.
Návaznosti
| GA16-11563S, projekt VaV |
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