In the PTB sections we have worked, especially where we have done extensive sampling, in China, Vietnam, Slovenia, and Turkey, we don't see black shale intervals through the boundary interval.

Thank you Brooks and thank you Thomas.

I much appreciate you writing back. I am grappling with this question only lately and therefore I am grateful for you improving my knowledge base. I am working on the high grade polymetallic-hydrocarbon-rich mineralization of the Kupferschiefer in Germany and Poland that can be proven to have happened in a hot-hydrothermal environment starting maybe as early as 280 m.y. and lasting maybe until mid-Triassic age, with many researchers liking the 250 +/- age date. I am attaching one of my recent publications for your info. And then there is the paper by GEORGIEV & STEIN & al. (2011) in Earth and Planetary Science Letters 310, 389-400 .... you may find in ResearchGate ... titled: HOT ACIDIC LATE PERMIAN SEAS STIFLE LIFE IN RECORD TIME .... that all together make me wonder if the stuff I am working on had anything to do with the bio-extinction at the Permian-Triassic boundary ..... there are sure not many happy looking fossils in the  mineralized Kupferschiefer ......... Again, thank you very much for your answers. If you like to continue this conversation, please use my private email: [email protected] THANKS & BEST,  VOLKER

You may think about a distinct change in palynological assemblages of permian and Triassic time. Specially in Gondwanaland the palynological difference is clear.

Volker,

Have you considered that the lack of fossil you are seeing is because the biota were all wiped out in the PT extinction, and it would have taken a considerable time before life in all its diversity was restored?

With regard to the announced possibly hydrothermal stimulus of biotic crises, note the recent paper on related theme (a killing effect of highly amplified expulsions of key biolimiting nutrients and metals included in sedex brines) by Poul Emsbo in Ore Geology Reviews:

http://www.sciencedirect.com/science/article/pii/S0169136816307594

In addition to the comment by Tom: the principal test is an insight in comprehensive data from the Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary, i. e,. at the Meishan section, South China. In the context of ongoing debate, papers presenting biodiversity losses versus evidences of various environmental changes across the P-T boundary in the shelf setting, including black shale and volcanic ash horizon, are exemplified by:

https://www.researchgate.net/profile/Wei_Wang240/publication/12416529_Pattern_of_Marine_Mass_Extinction_Near_the_Permian-Triassic_Boundary_in_South_China/

http://www.stratigraphy.org/upload/bak/Induan.pdf

https://www.researchgate.net/profile/Paul_Wignall/publication/249527451_Pyrite_framboid_study_of_marine_Permian-Triassic_boundary_sections_A_complex_anoxic_event_and_its_relationship_to_contemporaneous_mass_extinction/

https://www.researchgate.net/publication/223356673_Chapter_10_Late_Permian_double-phased_mass_extinction_and_volcanism_an_oceanographic_perspective/

Article Pattern of Marine Mass Extinction Near the Permian-Triassic ...

Article Pyrite framboid study of marine Permian-Triassic boundary se...

Article Chapter 10 Late Permian double-phased mass extinction and vo...