Suspicious impact craters and iridium layers

[Vladimír Socha <Seismosaurus@seznam.cz>]

Good day to all listmembers,
I finally finished reading David M. Raup's book "Extinction: Bad Genes or Bad 
Luck?" and I'd like to compare new data with those from the book (published in 
1990). Firstly, in the book there's a short list of all strata with (as for 
1990)discovered iridium anomalies:
Frasnian (Devonian) 367 mya
Callowian (Jurassic) 157 mya
Cenomanian (Cretaceous) 90 mya
KT boundary 65 mya
Eocene (Tertiary) 35 mya
Miocene (-"-) 12 mya
Pliocene (-"-) 3 mya
My question is: were any other layers found from 1990 until today? Were some of 
the listed revisited and/or rejected? Were already found meteor impact craters 
that could be attributed to these dates (esp. 157, 90, 3mya) ? 

Author than compares the age of the layers with then-known impact craters and 
mass extinction events. 4(3) of them seems to "match" time-wise with the Ir 
layer or ME event:
Siljan (Sweden) 52 km (in diameter) 368 mya (?)
Charlevoix (Quebec) 46 km 360 mya (367 Frasnian/Famennian)
Manicouagan (Quebec) 100 km 210 mya (208 Triassic/Jurasic)
Manson (Iowa) 32 km 65 mya (KT event)
+the ones that can be assigned to a smaller extinction events:
Clearwater (Quebec) 32 and 22 km 290 mya (Carb./Permian)
Popigai (Russia) 100 km 39(+-9) mya (Eocene/Oligocene)
Ries and Steinheim (Germany) 24 and 3.4 km 14.8 (+-0.7) mya (late middle 
Miocene extinction)
Chicxulub wasn't yet sufficiently studied in 1990, so author does mention it 
only briefly in the text.
My question as for the list above is: are there any new finds of craters that 
would fit into the dates, is there any revision given the new 
chronostratigraphy etc.? What's the current general opinion on the role of 
meteors in the mass extinctions events (not just the KT one)? And the same 
about a new study of 62 Ma cycle of extinction events? Thanks, in advance Vlad

"Dum vult dormire raptor, vult ornithopod(us) resilire"
http://dinosaurus.bloguje.cz/155186_item.php

   
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