Geologic Evidence:
Three main points lend themselves to the overall geologic evidence in support of hotspot activity coupled with plate migration along the Snake River Plain. First, evidence points to a "transgressive record" of volcanism indicating movement of the North American plate over the fixed mantle hotspot. Secondly, researchers have identified four zones or stages of past to present activity associated with the same mantle hotpot now beneath Yellowstone. Last, crustal deformation and uplift have been associated with the "cooling of the underlying crust and crustal load from the eruptions of post-hotspot basalts"(*4).
Forge a New Path?:
The North American plate migrates at a rate of approximately 4.5 mm/year over the "hotspot" (*4). Will continued movement eventually rendering Yellowstone an inactive reminder of its previous beauty?
Images 21 & 29 above, obtained from Idaho State University, indicate approximate age and activity of different elements of the Snake River Plain extending northeast to Yellowstone.
Other Areas of Interest:
SRP Areas:
Also a part of the Great Rift in the Snake River Plain are the Wapi Lava Fields (Image 1). It comprises around 300 sq. kilometers of relatively flat "pahoehoe lava "lobes" that extend to the east, west and northwest of the large center mass (*1). Image 58 shows an aerial extent of Hells Half Acre. Isolated farm land is enclosed by dark gray lava flows in the southeastern part of the SRP.
Web Links:
Visit the links below for Video on Craters of the Moon National Monument:
http://www.youtube.com/watch?v=JBxADn0znaY&feature=related
http://www.youtube.com/watch?v=XM0c0Rysax8&feature=related
http://bit.ly/HcPlam (Robert Limbert)
http://www.youtube.com/watch?v=JBxADn0znaY&feature=related
http://www.youtube.com/watch?v=XM0c0Rysax8&feature=related
http://bit.ly/HcPlam (Robert Limbert)