[meteorite-list] Nastapoka Arc, Hudson Bay, Canada - 2nd Try

[Paul H.]

In “Re: Changes in 14C and Impacts“
Sterling Webb wrote;

>I can suggest another very ancient crater:
>the south-southeastern coast of Hudson
>Bay, above James Bay is a portion of
>a perfect circle and it has a nice cluster
>of islands at the geometric center of
>that circle like the remnants of central
>peaks. I've always thought that it could
>be what's left of a very, very  ancient
>"astrobleme." 

The cluster of islands at the center of
the Nastapoka Arc in Hudson Bay has at 
various times caught the attention of 
many a geologist, planetologist, and
independent investigator and typically
proved to be a major disappointment to 
many a stalker of extraterrestrial impact
craters. They are the Beltcher Islands, 
which are an are an archipelago in 
Hudson Bay. Instead of consisting of 
older and highly brecciated and faulted 
strata that has been uplifted as part 
of a central uplift, they consist of
younger, softer, tightly folded 
Proterozoic metasedimentary and 
metavolcanic rocks that overlie the 
eroded surface of the older, harder, 
Archean gneisses that outcrop eastward
of the Nastapoka Arc. This Arc closely 
follows the unconformable contact between 
Archean Superior province gneisses 
and westward dipping early Proterozoic 
Belcher Group. The Belcher Islands are 
the exposed part of the Circum Ungava 
Fold Belt, which underlies the eastern 
edge of Hudson Bay. The fold belt consists 
of continental margins and a seaway that 
has been curshed between between two 
Archean landmasses during the Trans-Hudson 
Orogeny.

Web pages:

Belcher Islands
https://en.wikipedia.org/wiki/Belcher_Islands

Ricketts, B. D., and J. A. Donaldson, 1981,
Sedimentary History of the Belcher Group of 
Hudson Bay. In Proterozoic Basins of Canada; Geological Survey of Canada, Paper 81-10, 
p. 235-254
http://geoscan.nrcan.gc.ca/starweb/geoscan/servlet.starweb?path=geoscan/fulle.web&search1=R=109371
http://ftp2.cits.rncan.gc.ca/pub/geott/ess_pubs/109/109385/pa_81_10.pdf

Hynes, A., 1991, The gravity field of eastern Hudson Bay: Evidence for a flextural origin 
for the Hudson Bay (Nastapoka) Arc? Tectonics.
Volume 10, Issue 4, Pages 722–728, August 1991 
http://onlinelibrary.wiley.com/doi/10.1029/91TC00643/abstract

Dietz, R.S., and J.P. Barringer (1973) Hudson 
Bay Arc as an Astrobleme: a Negative Search. 
Meteoritics. vol. 8, pp. 28–29.
http://adsabs.harvard.edu/full/1973Metic...8...28D
http://adsabs.harvard.edu/abs/1973Metic...8...28D

Have you seen an Omar (Omarolluk erratic)? 
http://www.gov.mb.ca/iem/geo/surficial/omar_erratics.pdf

Yours,

Paul H.