Gibson, S.; Thompson, R.; Leat, P.; Morrison, M.; Hendry, G.; Dickin, A. Ultrapotassic Magmas Along the Flanks of the Oligo-Miocene Rio Grande Rift, USA: Monitors of the Zone of Lithospheric Mantle Extension and Thinning Beneath a Continental Rift. IKC abstracts 1991, 5, 133-135.