Abstract
Two distinct metamorphic events can be resolved in the N.E. Adirondacks through study of phase equilibria and stable isotoge geochemistry at occurrences of wollastonite. Low values of δ180 (to -1.3) at the wollastonite mines near Willsboro indicate that large amounts of heated meteoric water were involved in the formation of skarns at anorthosite contacts. This process is only consistent with magmatic intrusion and crystallization of anorthosite at relatively shallow depths (<10 km). Likewise, the formation of wollastonite, monticellite, and akermanite in a marble xenolith, surrounded by anorthosite at Cascade Slide, can best be explained by low pressure decarbonation reactions. Alternate theories of high pressure genesis for these minerals require large amounts of fluid infiltration to dilute CO2. Sharp gradients in δ180 across this xenolith prove that H2O could not have been such a diluent and no evidence exists for the presence of large amounts of any other fluid component. This evidence of shallow contact metamorphism is in marked contrast to the depths indicated by mineral barometers for the ensuing granulite facies metamorphism (23–26 km). These results, in conjunction with recent Sm-Nd geochronology, support shallow (<10 km) anorthosite intrusion and contact metamorphism at ~1.3 by. followed by deep granulite facies metamorphism at 1.1–1.0 by.
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References
Greenwood, H.J. (1967). Wollastonite: stability in H2O-CO2 mixtures and occurrence in a contact-metamorphic aureole near Salmo, British Columbia, Canada. Am. Mineral. 52, 1669–1680.
Isachsen, Y.W., McLelland, J., Whitney, P.R. (1975). Anorthosite contact relations in the Adirondacks and their implications for geological history. Geol. Soc. Am. Abstr. w. Prog. 7, 78–79.
Whitney, P.R. (1978). The significance of garnet “isograds” In granulite facies rocks of the Adirondacks. Geol. Surv. Can. Pap. 78-10, 357–366.
Tracy, R.J., Jaffe, H.W., Robinson, P. (1978). Monticellite marble at Cascade Mt., Adirondack Mountains, N.Y. Am. Mineral. 63, 991–999.
McLelland, J., Isachsen, Y. (1980). Structural synthesis of the southern and central Adirondacks: A model for the Adirondacks as a whole and plate-tectonic interpretations. Geol. Soc. Am. Bull. 91, 68–72, 208–292.
Valley, J.W., Essene, E.J. (1980). Akermanite in the Cascade Slide Xenolith, and its significance for regional metamorphism in the Adirondacks. Contr. Min. Pet. 74, 143–152.
Valley, J.W., O’Neil, J.R. (1982). Oxygen isotope evidence for shallow emplacement of Adirondack anorthosite. Nature 300, 497–500.
Whitney, P.R. (1983). A three-stage model for the tectonic history of the Adirondack Region, N.Y. New England Geol. 5, 61–72.
Whitney, P.R., McLelland, J.M. (1983). Origin of biotite-hornblende-garnet coronas between oxides and plagioclase in olivine metagabbros, Adirondack Region, N.Y. Contr. Min. Pet. 82, 34–41.
Valley, J.W., O’Neil, J.R. (1984). Fluid heterogeneity during granulite facies metamorphism in the Adirondacks: stable isotope evidence. Contr. Min. Pet. 85, 158–173.
Bohlen, SR., Valley JW Essene, EJ (1985). Metamorphism in the Adirondacks. I. Pressure and temperature. J. Petrol., in press.
Ashwal, L.D., Wooden, J.L. (1983). Sr and Nd isotope geochronology, geologic history, and origin of the Adirondack Anorthosite. Geochim. Cosmochim. Acta 47, 1875–1885.
Basu, A.R., Pettingill, H.S. (1983). Origin and age of Adirondack anorthosites reevaluated with Nd isotopes. Geology 11, 514–518.
Bohlen, S.R., Essene, E.J. (1978). Igneous pyroxenes from metamorphosed anorthosite massifs. Contr. Min. Pet. 65, 433–442.
Ollila, P.W., Jaffe, H.W. and Jaffe, E.B. (1984). Iron-rich inverted pigeonite: evidence for the deep emplacement of the Adirondack Anorthosite Massif. Geol. Soc. Am. Abstr. w. Prog., 54.
Lindsley, D.H. (1983). Pyroxene thermometry. Am. Mineral. 68, 477–493.
Valley, J.W., Essene, E.J. (1980). Calc-silicate reactions In Adirondack marble: the role of fluids and solid solution. Geol. Soc. Am. Bull. 91, 114–117, 720–815.
Putman, G.W. (1958). Geology of some wollastonite deposits in the Eastern Adirondacks, New York. MS thesis, Penn. State Univ., 105 p.
Buddington, A.F. (1939). Adirondack igneous rocks and their metamorphism. Geol. Soc. Am. Mem. 7, 354 p.
French, B.M. (1966). Some geological implications of equilibrium between graphite and a C-O-H gas phase at high temperatures and pressures. Rev. in Geophys. 4, 223–253.
Valley, J.W., Peterson, E.U., Essene, E.J., Bowman, J.R. (1982). Fluorphlogopite and fluortremolite in Adirondack marbles and calculated C-O-H-F fluid compositions. Am. Mineral. 67, 545–557.
Fyfe, W.S. (1973). The granulite facies, partial melting, and the Archean crust. Phil. Trans. Roy. Soc. Lond. 273A, 457–461.
Newton, R.C., Smith, J.V., Windley, B.F. (1980). Carbonic metamorphism, granulites, and crustal growth. Nature 288, 45–50.
Hoschek, G. (1976). Zur Stabilitat von Clintonite im system Ca0-Mg0-Al203-Si02-H20-C02. Fort, der Min., 39–40.
Taylor, H.P. (1969). Oxygen isotope studies of anorthosites with particular reference to bodies in the Adirondack Mts., N.Y. N.Y. State and Sci. Ser. Mem. 18, 111–134.
Veizer, J., Hoefs, J. (1976). The nature of 180/160 and 13C/12C secular trends in sedimentary carbonate rocks. Geochim. Cosmochim. Acta 40, 1387–1395.
Emslie, R.F. (1978). Anorthosite massifs, rapikivi granites, and late Proterozoic rifting of North America. Precamb. Res. 7, 61–98.
Morse, S.A. (1982). A partisan review of Proterozoic anorthosites. Am. Mineral. 67, 1087–1100.
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Valley, J.W. (1985). Polymetamorphism in the Adirondacks: Wollastonite at Contacts of Shallowly Intruded Anorthosite. In: Tobi, A.C., Touret, J.L.R. (eds) The Deep Proterozoic Crust in the North Atlantic Provinces. NATO ASI Series, vol 158. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-5450-2_13
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DOI: https://doi.org/10.1007/978-94-009-5450-2_13
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