Prograde amphibole dehydration reactions during high-grade regional metamorphism , central Massachusetts "

s with Programs, I l, 504. Robinson, Peter, Jaffe, H.W. , Klein, Cornelis, Jr., and Ross, Malcolm 970 HOLLOCHER: AMPHIBOLE DEHYDRATION REACTIONS ( I 969) Equilibrium coexistence of three amphiboles. Contributions to Mineralogy and Petrology, 22, 248-258. Robinson, Peter, Jaffe, H.W. , Ross, M. , and Klein, C. (l97la) Orientations of exsolution lamellae in clinopyroxenes and clinoamphiboles; Consideration of optimal phase boundaries. American Mineralogist, 56, 909-939. Robinson, Peter, Ross, Malcolm, and Jaffe, H.W. (l97lb) Composition of the anthophyllite-gedrite series, comparisons of gedrite and hornblende, and the anthophyllite-gedrite solvus. American Mineralogist, 5 6 , 1 0 0 5 1 0 4 1 . Robinson, Peter, Ross, M. , Nord, G.L. , Jr., Smyth, J.R. , and Jaffe, H.W. (1977) Exsolution lamellae in augite and pigeonite: Fossil indicators of lattice parameters at high temp€rature and pressure. American Mineralogist, 62, 857 -87 3. Robinson, Peter, Spear, F.S. , Schumacher, J.C. , Laird, Jo, Klein, Cornelis. Evans, B.W. , and Doolan, B.L. (1982a) phase relations ofmetamorphic amphiboles: Natural occunence and theory. In Mineralogical Society of America Reviews in Mineralogy, 98, l-227 . Robinson, Peter, Tracy, R.J., Hollocher, Kurt, and Dietch, C.W. (19g2b) High grade Acadian regional metamorphism in south-central Massachusetts. In R. Joesten and S.S. Quarrier, Eds., New England intercollegiale geological conference guidebook, 74th Annual Meeting, p. 2g9339. Storrs, Connecticut. Robinson, Peter, Tracy, R.J., Hollocher, Kurt, Schumacher, John, and Berry, H.N. , IY (1986) The central Massachusetts metamorphic high. In Peter Robinson and D.C. Elbert, Eds., Regional metamorphism and metamorphic phase relations in northwestern and central New EngLand. International Mineralogical Association Field Trip Guidebook, Trip B-5, p. 195-284. University of Massachusetts, Amherst, Massachusetts. Robinson, Peter, Tucker, R.D. , and Hollocher, Kurt (1989) The nature of the Bronson Hill zone during the Taconian Orogeny. In Maurice Colpron and Barry Doolan, Eds., proceedings ofthe euebec-yermont Appalachian Workshop, University of Yermont, Burlington, Vermont, 26-28. Russ-Nabelek, C. (1989) Isochemical contact metamorphism of mafic schist, Laramie Anorthosite Complex, Wyoming: Amphibole compositions and reactions. American Mineralogist, 74, S3O-548. Schumacher, John (1983) Srmtigraphic, geochemical, and petrologic studies of the Ammonoosuc Volcanics, north-central Massachusetts and southwestern New Hampshire,237 p. Ph.D thesis, Massachusetts, Amherst, Massachusetts. Schumacher, John, and Robinson, Peter (1987) Mineral chemistry and metasomatic growth of aluminous enclaves in gedrite-cordierite-gneiss from southwestem New Hampshire, USA. Joumal of petrology,28, 10331073. Spear, F.S. (1978) Petrogenetic grid for amphibolites from the Post Pond Volcanics, Vermont. Carnegie Institution of Washington Year Book, 77, 805-808. (1980) The gedrite-anthophyllite solvus and the composition limits of orthoamphibole from the Post Pond Volcanics, Vermont. American Mineralogist, 65, 1103-l I18. -(1982) Phase equilibria of amphibolites from the Post Pond Volcanics, Mt. Cube Quadrangle, Vermont. Journal ofPetrology,23, 383426. Stoddard, E.F. (1985) Zoned plagioclase and the breakdown of hornblende in pyroxene amphibolites. Canadian Mineralogist, 23, 195-204. Tracy, R.J., Robinson, Peter, and Thompson, A.B. (1976) Garner composition and zoning in the determination oftemperature and pressure of metamorphism, central Massachusetts. American Mineralogist, 61, 762-77 5. Wolfi R.A. (1978) Ultramafic lenses in the Middle Ordovician Panridge Formation, Bronson Hill anticlinorium, central Massachusetts, 162 p. M.S. thesis, University of Massachusetts, Amherst, Massachusetts. Znn,E-An, Ed. (l 983) Bedrock geologic map ofMassachusetts, l:250,000. U.S. Geological Survey, 3 sheets. MnNuscrum REcETvED Jexunnv 2, 1990 Maroscnrm AccEF.rED Fssruanv 11, 1991 AppENDrx 2. Samples used from other studies This paper Original sample no. Metamorohic zone