Mineralogy and Petrology 2002) 76: 99±120 DOI 10.1007/s00710-001-0190-z Contact metamorphism of siliceous dolomite and impure limestones from the Werfen formation in the eastern Monzoni contact aureole E. Povoden, M. Horacek, and R. Abart  Institut f ur Mineralogie und Petrologie, Karl-Franzens-Universit at, Graz, Austria Received April 7, 2001; revised version accepted December 6, 2001 Published online June 20, 2002; # Springer-Verlag 2002 Summary The intrusive complex of Monzoni in the western central Dolomites northern Italy) comprises a suite of pyroxenites, monzogabbros and monzodiorites with solidus temperatures in excess of 1000  C which intruded previously unmetamorphosed Permotriassic sediments at less than 5 km depth. At the eastern intrusive contact an approximately 860m wide contact aureole is developed in the carbonate country rocks. The prograde sequence of mineral parageneses in a siliceous dolomite of the Cencenighe member and in marly limestones of the Val Badia and Cencenighe mem- bers of the Lower Triassic Werfen formation indicate peak metamorphic temperatures in excess of 698  C at 185 m from the intrusive contact and an outward temperature decrease of approximately 65  C per 100 m. The high temperatures in the inner aureole caused formation of periclase from the prograde breakdown of dolomite and formation of melilite and esseneite-rich clinopyroxene. Introduction Contact metamorphism of carbonate rocks has been a major issue in metamorphic petrology for several decades Kerrick, 1991; Voll et al., 1991). The characteristic features of contact metamorphism are its largely isobaric nature, relatively well de®ned characteristics of the heat source, and the relatively well constrained cor- relation between corresponding lithologies in low- and high-grade portions of a  Present address: Mineralogisch-Petrographisches Institut, Universit  at Basel, Switzerland