Talk:Columbia River Basalt Group

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Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:05, 16 January 2022 (UTC)

better map to upload
also from USGS: http://vulcan.wr.usgs.gov/LivingWith/Historical/LewisClark/Maps/map_columbia_river_flood_basalts.html -Pete (talk) 05:22, 26 June 2008 (UTC)

Yes, time to work on a better map for the introduction. The existing one (also seen below) is not out and out bad – it does show the areal extent of the CRB in the regional context, and is not a bad graphic per se – but it is cluttered with other details not relevant to this article. Also, it would be nice if we could get a similar map that shows the individual units.
 * The image at vulcan.wr.usgs.gov is comparable, but the additional text in the image won't work well in the reduced size needed for the lede.
 * Camp and Ross have some very nice images in their "Radiating Volcanic Migrations" article at MantlePlumes.org. (And we are arranging permission to use these.) I think fig. 2 would work, though some of the text is not as clear as I would like, and the individual units are not shown.
 * Update: see File:CRBG_distribution_RVM-2.jpg and File:CRBG_distribution_RVM-5.jpg.
 * Ooops, had to retract those. Better images coming. 23:13, 2 January 2012 (UTC)


 * Camp and Hanan's fig. 5b at is also a likely candidate, esp. as it has the individual units. The drawback is that the shaded-relief background darkens and obscures the image. If someone wanted grab a copy of that and see if the background could be lightened it would be strong candidate.
 * There are some good images in PNNL 15221 (where the existing image came from). Fig. 3 (p. 2.3) is esp. good as a graphic, but unfortunately it is illustrating structural features of part of the CRB. Fig. 6b shows individual flows, but again there is a problem with the black background, and small labels. However, I suspect ImageMagick might be able to reduce the background to a nice gray. Perhaps even replace the labels.

There are a few other images (and in multiple versions) out there, but I think none as good as these. Anyone think any of these, or a possibly reworked version, might be an improvement over the existing image? ~ J. Johnson (JJ) (talk) 21:55, 10 December 2011 (UTC)

I have just forwarded the permissions, so we should be good to go with these wonderful images:
 * File:Columbia_River_Flood-Basalt_Province.jpg
 * File:CRB-Yellowstone_mantle_plume_model.jpg
 * ~ J. Johnson (JJ) (talk) 00:31, 21 January 2012 (UTC)


 * Very cool!! Thanks for working on this, JJ! The maps look great. -Pete (talk) 01:24, 21 January 2012 (UTC)

References; Harv; pages needed.
Notable changes: I have moved the reflist to a new Notes section, populated References with the corrected, augmented, and templated forms of the references previously buried in the main text, replaced all the "named refs" (and merged where appropriate) with a Harv citation, and checked the links to the references.

I have scattered a few inline tags throughout (as well as leaving in empty "p. ") to highlight that WP:page numbers are needed. (A major failing of relying on individual "named refs" -- specific citation is difficult, so tends to be left off.) Other problems noted in the text. ("That should hold the .....s". :-0 ) - J. Johnson (JJ) (talk) 00:09, 3 September 2011 (UTC)

comparison to Central Atlantic Magmatic Province ??
Before 200Ma, a spreading ridge running east-west through the length of the ancient Tethys ocean gradually opened up that seaway. About 200Ma, the western end of that Mid-Ocean Ridge (MOR) reached, and ran under, the supercontinent of Pangea, between Africa (to the south) and North America (to the north), as indicated in the following figures:
 * http://imageshack.us/a/img29/4546/insularislands400200mya.png
 * http://imageshack.us/a/img441/3249/insularislands20050mya.png

Now, about 50Ma, the west coast of North America obducted over another MOR (the east Pacific rise). The spreading ridge underneath the continental crust caused crustal thinning, and minor rifting, generating the Basin and Range province, as well as the Yellowstone hotspot and Columbia River Basalt Group. Thus, the CAMP resembles those continental rift zones, except running perpendicular to the coast (instead of parallel to), and on a larger scale, which successfully rifted Africa from North America. Perhaps rifting is facilitated, by perpendicular incidence, of the spreading zone??

More speculatively, about 95Ma, the Tethys MOR may have been subducted under Eurasia, pulling India, then Africa, northwards towards Eurasia. About that time, northern Africa was flooded, leading to the extinction of large northern African dinosaurs & reptiles, like Spinosaurus, Carcharodontosaurus, Paralititan, Sarcosuchus (according to the BBC documentary Planet Dinosaur). Perhaps a change, from compressive force coming southwards from a MOR into northern African continental crust, before 95Ma; to an extensional force pulling northwards to a Subduction Zone (SZ) before Eurasia; caused the northern African crust to stop thickening, and start thinning, depressing the surface below Tethys-sea level?? 66.235.38.214 (talk) 12:49, 17 October 2012 (UTC)
 * Yes, all that is very interesting stuff. Do you have a specific question or suggestion regarding this article? ~ J. Johnson (JJ) (talk) 23:14, 17 October 2012 (UTC)
 * Perhaps people in the field are familiar with scholarly & citable sources? Legitimate geologic connections would benefit the article.  66.235.38.214 (talk) 07:29, 18 October 2012 (UTC)
 * I am generally in favor of showing contexts and broad connections. "Perhaps" you think this article needs more that? Fine.  Can you make a specific suggestion? ~ J. Johnson (JJ) (talk) 18:08, 18 October 2012 (UTC)