Abstract
A suite of pelitic schists from the contact metamorphic aureole around the syenite stock at Ascutney Mountain, Vermont, shows a decrease in the amounts of cordierite, quartz, and andalusite and an increase in pleonaste and corundum as the contact is approached. Whole rock chemical analyses show a distinct SiO2 concentration gradient from the wall rocks toward the intrusion; however, the syenite has a higher weight percent SiO2 than the adjacent schists. It is suggested that silica diffused down an SiO2 activity gradient into the intrusive; other major oxide components were apparently immobile. The diffusion of silica was probably through intergranular fluids, and the amount of silica available for diffusion was governed by the solubilities of cordierite, andalusite, and quartz in the interstitial fluid.
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References
Carmichael, I.S.E., Nicholls, J., Smith, A.L.: Silica activity in igneous rocks. Am. Minelogist 55, 246–263 (1970).
Chapman, R.W., Chapman, C.A.: Cauldron subsidence at Ascutney Mountain, Vermont. Geol. Soc. Am. Bull. 51, 191–212 (1940).
Daly, R. A.: The geology of Ascutney Mountain, Vermont. U. S. Geol. Surv. Bull. 209, 122 p. (1903).
Medlin, J.H., Suhr, N.H., Bodkin, J.B.: Atomic absorption analysis of silicates employing LiBO2 fusion. A. A. Newsletter 8, 25–33 (1969).
Naeser, C.W.: The use of apatite and sphene for fission track age determinations. Geol. Soc. Am. Bull. 78, 1523–1526 (1967).
Robie, R.A., Waldbaum, D.R.: Thermodynamic properties of minerals and related substances at 298.15°K (26°C) and one atmosphere (1.013 bars) pressure and higher temperatures. U. S. Geol. Surv. Bull. 1259, 256 p. (1968).
Rose, H.J., Adler, I., Flanagan, F.J.: Use of La2O3 as a heavy absorber for X-ray fluorescence analysis of silicate rocks. U. S. Geol. Surv. Profess. Paper 450 B, 80–82 (1962).
Taylor, H.P., Forester, R.W.: Low O18 igneous rocks from the intrusive complexes of Skye, Mull, and Ardnamurchan, Western Scotland. J. Petrol. 12, 465–497 (1971).
Turner, F.J.: Metamorphic petrology mineralogical and field aspects, 403 p. New York: McGraw-Hill 1968.
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Nielson, D.L. Silica diffusion at Ascutney Mountain, Vermont. Contr. Mineral. and Petrol. 40, 141–148 (1973). https://doi.org/10.1007/BF00378171
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DOI: https://doi.org/10.1007/BF00378171
