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I found this specimen in Laval, on the South shore, West side. There was a fall there, next to the river there is a mixture of different layers. The time should be after Ordovician or late Ordovician. The rock is black, on very thin flat layers. Some layers are very hard / silicates/ other are fragile, mud - coal . Initially I expected it to be nautiloid. But when I did the pictures I rejected it. 1. Both parts 2. 3. 4. Side view - both parts 5. Cleaned (lower part) 6. 7. 8. 9. 10. 11.

Belo are a great series of lectures (2016) that summarizes what is known and unknown about the Cryogenian. Earth Dynamics Research Group CCFS sponsored short course on Snowball Earth https://www.youtube.com/playlist?list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n Snowball Earth Lecture 1 - Snowball geology Earth Dynamics Research Group https://www.youtube.com/watch?v=RxFmcgjXtgI&t=0s&list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n&index=2 Snowball Earth Lecture 2 - Snowball climate dynamics Earth Dynamics Research Group https://www.youtube.com/watch?v=8ZTR-DaT-w0&t=0s&list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n&index=3 Snowball Earth Lecture 3 - Snowball geochemistry Earth Dynamics Research Group https://www.youtube.com/watch?v=AfC-YRLCKGU&t=0s&list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n&index=4 Snowball Earth Lectures 4&5 - Snowball geobiology & The origin of Laurentia Earth Dynamics Research Group https://www.youtube.com/watch?v=vrjmSVcIGo0&t=0s&list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n&index=5 Snowball Earth Lecture 6 - The Great Oxidation Event and a Siderian snowball earth Earth Dynamics Research Group https://www.youtube.com/watch?v=z2zXLswH02s&t=0s&list=PLb5FFe99h_Lg_t5_67MG1OIKMjOPqFS4n&index=6 Yours, Paul H.

Cornwall and south Devon 'originally part of mainland Europe' Study reveals Britain acquired regions when struck by land bearing what is now France, Ima Sample, The Guardian https://www.theguardian.com/science/2018/sep/14/cornwall-and-south-devon-originally-belonged-to-europe The open access paper is: Arjan H. Dijkstra, and Callum Hatch, 2018, Mapping a hidden terrane boundary in the mantle lithosphere with lamprophyres Nature Communications. 9, Article number: 3770 https://www.nature.com/articles/s41467-018-06253-7 Yours, Paul H.

Interesting open access paper on mass extinctions. Jones, D. S., A. M. Martini, D. A. Fike, and K. Kaiho, 2017, A volcanic trigger for the Late Ordovician mass extinction? Mercury data from south China and Laurentia. Geology v. 45; no. 7; p. 631–634 http://geology.geoscienceworld.org.libezp.lib.lsu.edu/content/45/7/631 http://geology.geoscienceworld.org.libezp.lib.lsu.edu/content/45/7 Yours, Paul H.

Anyone have any information on tectonic activity during the Cambrian Period? I am writing a report on tectonic activity on Earth and am going to use the Cambrian to explain the location of the Burgess Shale and Chengjiang formations. So far I have a good idea of what I am doing, just wanted some input from others. I'll reference anyone that responds. Thanks.