Pyrite generations from the Permian/Triassic boundary section, Bálvány, Bükk Mts., Hungary
Reference:
Acta Mineralogica-Petrographica, Szeged 2008, Vol. 48, pp. 49-53.
Szerző:
Zajzon Norbert
Vető István
Abstract:Three pyrite generations were described in the Bálvány Composite Section based on morphology, WDX and δ34S data. Among them the 0.1–0.2 mm size, isotopically light euhedral pyrite is early diagenetic. This generation was found in the whole section. The “boundary shale” is characterised by microbial pyrite framboids, which formed on the surface, or close to the surface of the sediment around the redox boundary with the presence of dysoxic bottom-water. This, and the laminated structure of the sediment prove anoxic conditions in the whole sediment. Most probably there was dysoxic bottom water. The third generation is also euhedral, but has a larger grain size (1–2 mm). Based on δ34S data and sphalerite inclusions, this generation is of late diagenetic or hydrothermal origin. This type occurs only in the shale and the top of the underlying limestone. The sulphides of the section are almost totally oxidised.
[searchwords]acta2008-2009,Bálvány-hill,Permian – Triassic boundary,pyrite,δ34S[/searcwords]
