Mantle xenoliths and new constraints on the origin of alkaline ultrapotassic rocks from the Alto Paranaíba and Goiás igneous provinces, Brazil - Gaspar, J.C.; Araujo, A.L.N.; Carlson, R.W.; Sichel, S.E.; Brod, J.A.; Sgarbi, P.B.; Danni, J.C.M. (International Kimberlite Conference: Extended Abstracts, 2003)