Talk:Amboy Crater

Initial assessment per proj calif
Barely makes it to start class. to advance it needs lots of expansion in ecology, geology and some sort of map. more refs too. Anlace 23:26, 24 October 2006 (UTC)

Amboy is actually the eastern outpost of several Quaternary volcanic centers on the Route 66 corridor within California. Approximately 8 miles west of the Amboy Lava Fields lies the Bagdad Cone Complex, a group of four agglutinate cones not much older than Amboy. These craters are interesting in that the lavas brought up chunks of unmelted mantle rock. Directly south of this field is the Ordnance Cone Complex, of a similar age. Farther west, I-40 crosses the extensive Pisgah Lava Field. The cinder cone of this field was mined for cinders at one time. Directly across Lavic Lake (dry) from the Pisgah Field is the Lavic Flow and the Sunshine Cone Flow. K-Ar dates for these flows are approximately 800ky and 200ky respectively. Still farther west, in the Rodman Mountains, lies the Malpais Flow and associated cinder cone. The cone here was also quarried at one time.

Other Quaternary volcanic centers are scattered throughout the Mojave. One good example is the Cima Volcanic Field, south of the town of Baker, on the I-15 corridor.

Category Craters
On 25 March Seattle Skier removed Category:Craters of the United States from this article, stating that "it is for impact craters". The correct category for impact craters is Category:Astroblemes. Craters includes all types of craters. This includes volcanic craters and subsidence craters. --Bejnar 07:42, 25 March 2007 (UTC)
 * (NOTE: this reply is cross-posted from my talk page.) As far as I could tell, Category:Craters was populated with 99% non-volcanic craters, essentially all impact craters (there may be subsidence craters in there, but I haven't found them yet). So I have removed those tags from the 3 volcanic craters I found it on thus far: Zuni Salt Lake, Amboy Crater, and Valle Grande.  I also removed the tags (more reluctantly) from three other volcano-related articles; volcanic crater, caldera, and pseudocrater.
 * There are well over 1400 volcano articles on WP, and the overwhelming majority of these volcanoes have craters (and perhaps up to 100 may have "Crater" in their name, too). If ony 3 of them  were listed under Category:Craters (there may be a few more, too, which I haven't found yet), then it seems completely appropriate to remove the tags from those few instead of adding it to 1000+ articles.
 * Also, Category:Craters of the United States had been set as a subcat of Category:Volcanoes of the United States. This was totally incorrect if only a tiny fraction of the items in it were volcanoes (and also such a subcat relationship existed only for the US, not other countries), so I have fixed it.
 * Whatever the intent of the creators of Category:Craters was, it is unknown to me, but the category is now de facto an impact craters category, and excludes volcanoes. If you have any info or insight on the original intent, I would love to know.   Thanks.  --Seattle Skier (talk) 08:25, 25 March 2007 (UTC)

Dating of crater
The date of the Amboy crater per the BLM is all over the place. Their pamphlet says "10,000 years" and a plaque at the location say "500 years" for the last eruption. However the Arizona State University Geographic Alliance published a study that shows an age of 79,000 years (+/- 5,000 years). The same study says that, "Prior age constraints have been weak" - and quotes several earlier studies that show ages of less than 6,000 and less than 1000 years. The earlier studies are based on appearance of the lava flows, and the ASU study is based upon surface degradation and erosion of the lava flows.

I have tried to make a minimal correction to this article to indicate the true age and refer to the ASU study. I also wanted to indicate that the BLM data is incorrect. I presume the BLM data is out of date due to budget restraints. I've added an image link to the BLM plaque in question. Calladus (talk) 17:47, 25 March 2013 (UTC)