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The other day I decided to switch from the usual Paleozoic and look for Pleistocene fossils in the city of Chicago. Because of the pandemic, the streets were barren, so driving around was very easy. Here is Michigan Ave & Wacker Drive, a normally bustling, congested intersection.. empty and quiet. I wasn't expecting to find anything and have a nice drive. There were a couple areas I was interested in exploring, the first looked promising but revealed only glacial till/sand/clay. The second area I was surprised upon close inspection to find tiny fossil mollusks in the unearthed lacustrine glacial deposit. No saber toothed cats or mastodon teeth, of course, but still a nice surprise. I collected as many as could find in the small exposure. This would be Wisconsin Episode, Equality Formation, Dolton Member. I'm not sure what phase of glaciation Lake Michigan was at around this time, but from what I can glean from reports, this would be between 8,000- 26,000 BP, I believe. Amnicola sp. Pisidium sp. ? ? Group shot. The only literature I can find regarding Pleistocene mollusks deals with NW and central Illinois. Also had some fun with the sand under cross polarized light. The sand grains look more angular and jagged than local beach samples. After collecting the mollusks, I made my way up to Juneway beach on the far north side . It is a beach that has recently been completely engulfed by Lake Michigan and the city had to dump Silurian dolomite to thwart erosion. It is a modern "lost beach." Thanks for reading!

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.

Campionserpukmaloofochemistry-_Geophysics-_Geosystems.pdf Constraining the Timing and Amplitude of Early Serpukhovian Glacioeustasy With a Continuous Carbonate Record in Northern Spain Alison Campion , Adam Maloof, Blair Schoene , Sergey Oleynik, Javier Sanz-Lopez , Silvia Blanco-Ferrera , Oscar Merino-Tome , Juan Ramon Bahamonde, and Luis Pedro Fernandez Geochemistry,Geophysics, Geosystems, 19. https://doi. org/10.1029/2017GC007369

Researchers suggest missing crust layer can be blamed on 'Snowball Earth' January 3, 2019 by Bob Yirka, Phys.org https://phys.org/news/2019-01-crust-layer-blamed-snowball-earth.html Around the world, miles of rock are missing. Could ‘Snowball Earth’ be the culprit? by Julian Rosen, Los Angeles Times, January 3, 2019 https://www.latimes.com/science/sciencenow/la-sci-sn-snowball-earth-geology-20190103-story.html the paper is: C. Brenhin Keller et al. Neoproterozoic glacial origin of the Great Unconformity, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1804350116 https://www.pnas.org/content/early/2018/12/26/1804350116 Yours, Paul H.

Kornei, K. (2018), Tiny algae may have prompted a mass extinction, Eos, 99, https://doi.org/10.1029/2018EO102539. Published on 11 July 2018. https://eos.org/articles/tiny-algae-may-have-prompted-a-mass-extinction https://eos.org/wp-content/uploads/2018/08/eos0918.pdf?x69145 https://eos.org/current-issues The paper is; Shen, J., Pearson, A., Henkes, G.A., Zhang, Y.G., Chen, K., Li, D., Wankel, S.D., Finney, S.C. and Shen, Y., 2018. Improved efficiency of the biological pump as a trigger for the Late Ordovician glaciation. Nature Geoscience, 11(7), p.510. https://www.nature.com/articles/s41561-018-0141-5 Yours, Paul H.

QUAT glacai The Scheldt estuary trawl crowd might find this useful,perhaps About 5-10 mB each,source: JGSL,jan 2018 issue

Feulner, G., 2017. Formation of most of our coal brought Earth close to global glaciation. Proceedings of the National Academy of Sciences, 114(43), pp. 11333-11337. Abstract: http://www.pnas.org/content/114/43/11333.short https://www.ncbi.nlm.nih.gov/pubmed/29073052 Paper: https://pdfs.semanticscholar.org/0b23/8273be5a2b4f06d7fb1e5932b45f731944be.pdf Yours, Paul H.