Marcasite at the Permian‐Triassic Transition

Lounejeva, E; Steadman, Jeffrey A.; Rodemann, Thomas; Large, Ross R.; Danyushevsky, L. V.; Mantle, Daniel; Grice, Kliti; Algeo, Thomas J.

doi:10.1002/9781119507444.ch16

Cited by 5 publications

(4 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As in the Doushantuo Formation, the differential compaction of sediment laminae around sulfide rosettes in these black shales is evidence for an early diagenetic origin. Marcasite-pyrite intergrowth textures have also been reported from sedimentary sequences at the Permian-Triassic Boundary (PTB), which were interpreted as evidence of a sudden acidification of late Permian seawater 71,72 . Although some of these textures are similar to the Doushantuo PMRs, the PTB marcasites typically have highly depleted δ 34 S values (ca.…”

Section: Discussionmentioning

confidence: 94%

Evidence for high-frequency oxygenation of Ediacaran shelf seafloor during early evolution of complex life

Jiao,

She,

Papineau

et al. 2023

Commun Earth Environ

Self Cite

View full text Add to dashboard Cite

Increasing oxygenation of the early Ediacaran Ocean is thought to have been responsible for the emergence of early animals. Although geochemical studies have suggested periods of oceanic oxygenation in the Ediacaran, direct evidence for seafloor oxygenation has been lacking. Here, we report frequent occurrences of distinctive, sub-millimetric, and early diagenetic pyrite-marcasite rosettes in phosphorites from the lower Ediacaran Doushantuo Formation (Weng’an, South China). They typically consist of a nucleus of framboidal pyrite, a cortex of radiating marcasite blades intergrown with quartz, and a rim of second-generation pyrite, recording partial oxidative dissolution of pyrite and co-precipitation of marcasite and quartz. This inference is further supported by near-zero carbon isotope values of the host dolostone, similarly low sulfur isotope values for pyrite and marcasite, and evident Fe-isotope fractionation between marcasite and pyrite. Collectively, our findings reveal intermittent bottom-water and porewater oxygenation events, providing direct evidence of high-frequency oxygenation of Ediacaran continental shelves.

show abstract

Section: Discussionmentioning

confidence: 94%

Evidence for high-frequency oxygenation of Ediacaran shelf seafloor during early evolution of complex life

Jiao,

She,

Papineau

et al. 2023

Commun Earth Environ

Self Cite

View full text Add to dashboard Cite

show abstract

“…3,4 Besides, considering the unique acidic conditions needed for marcasite formation, researchers have used marcasite and its sulfur isotopic composition to track ocean acidification events in Earth's history. 10,13,14 In many cases, marcasite occurs as intergrowth with pyrite. 3,4 Since marcasite and pyrite have similar physical properties, it is hard to separate marcasite from the marcasite-pyrite intergrowth.…”

Section: Introductionmentioning

confidence: 99%

“…Despite this, marcasite in sedimentary rocks has become the focus of some research because it is indicative of acidic conditions in deep time. 10,13,14 Sulfur has four stable isotopes ( 32 S, 33 S, 34 S, and 36 S), which have natural abundances of approximately 95.04%, 0.75%, 4.20%, and 0.01%, respectively. 15 Since the difference in their atomic masses is relatively large, sulfur isotopes could be easily fractionated in geological processes.…”

Section: Introductionmentioning

confidence: 99%