[Rockhounds] Late Ordovician mass extinction - volcanism and warming or cooling and glaciation?

[Paul]

There is a series of open access papers about what
caused the Late Ordovician mass extinction. They are:

Bond, D.P. and Grasby, S.E., 2020. Late Ordovician
mass extinction caused by volcanism, warming, and
anoxia, not cooling and glaciation. Geology.
https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G47377.1/586486/Late-Ordovician-mass-extinction-caused-by

Mitchell, C. E., and  Melchin, M.J., 2020. COMMENT:
Late Ordovician mass extinction caused by volcanism,
warming, and anoxia, not cooling and glaciation. Geology
https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G47946C.1/587311/COMMENT-Late-Ordovician-mass-extinction-caused-by

Bond, D.P. and Grasby, S.E., 2020. REPLY: Late
Ordovician mass extinction caused by volcanism,
warming, and anoxia, not cooling and glaciation. Geology.
https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G47984Y.1/587312/REPLY-Late-Ordovician-mass-extinction-caused-by

Wang, G., Zhan, R. and Percival, I.G., 2019. The
end-Ordovician mass extinction: A single-pulse
event?. Earth-Science Reviews, 192, pp.15-33.
https://www.sciencedirect.com/science/article/pii/S0012825218305099
https://www.researchgate.net/publication/331275476_The_end-Ordovician_mass_extinction_A_single-pulse_event
https://www.researchgate.net/profile/Gx_Wang2

Yours,

Paul H.