The Journal of the Petrological Society of Korea (암석학회지)

The Petrological Society of Korea (한국암석학회)
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Regional-scale metasomatism of Al, K, and Na during stauroliteandalusite- grade contact metamorphism, in the southwestern Nova Scotia, Canada

십자석-홍주석 접촉 변성과정에 수반된 Al, K, Na의 광역적 변성교대작용 - 캐나다 노바스코시아주 서남부의 예 -

  • Sang-Gi Hwang (Department of Earth Resources and Environmental Engineering, PaiChai University)
  • Published : 1997.06.01
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Abstract

Pelitic rocks of southwestern Nova Scotia have been affected by widespread contact metamorphism due to the intrusion of the Shellburne Pluton, with aureole up to 15 km wide. Well-preserved pseudomorphic textures indicate that common staurolite and andalusite metacrysts formed at the expense only of plagioclase, muscovite and biotite. Excess components (K, Na and Ca) from such replacement reactions imply extensive metasomatism throughout the contact aureole. Modal analysis of a typical andalusite-bearing rock indicates a one-to-one volume ratio of product to reactant. However the products of the replacement reactions contain approximately three times more aluminum than the reactants, indicating that the regional metasomatism also involved aluminum.

캐나다 노바스코시아주 남서쪽에 분포하는 이질암류는 셀르론화강암의 관입에 의해 넓은 지역이 접촉변성을 받았다. 이곳에 분포하는 접촉변성대는 15km 두께에 이른다. 잘 발달된 가상구조(pseudomorphic textures)에 의하면 사장석-백운모-흑운모가 십자석과 홍주석으로 치환되어있다. 이러한 치환반응이 가능하려면 반응물에는 존재하나 생성물에는 존재하지 않는 K, Na, Ca 원소들의 반응게에서 빠져 나와야만 가능하다. 이는 연구지역에서 원소들이 넓은 접촉 오레올을 이동한 광역의 변성교대작용이 발생하였음을 암시해 주고 있다. 홍주석을 함유하는 전형적인 시료의 모달 분석결과 반응물과 생성물의 체적비율이 1:1 관계를 보이고 있다. 동일체적일 경우 생성물(홍주석)에 함유된 Al의 양이 반응물들(사장석-백운모-흑운모)에 함유된양 보다 3배가 많음을 감안할때 이러한 화학반응을 가능하게 하려면 Al 역시 접촉변성 지역에서 원거리를 이동하였다는것을 알 수 있다.

Keywords

References

  1. Contributions to Mineralogy nad petrology v.20 On the mechaninsm of prograde metamorphic reactions in quatz-bearing pelitic rocks Carmichael, D.M.
  2. M. SC. thesis, Acadia University Matamorphism of the Meguma Group in the Shelburne Area, Nova Soctia Chu, P.H.T.
  3. Ore Geology Reviews v.2 The role of fluids in syntectonic mass transport and the localization of metamorphic vein type ore deposits Cox. S.F.;Etheridge, M.A.;Wall, V.J.
  4. Journal of Metamorphic Geology v.1 The role of the fluid phase during regional metamorphism and deformation Etheridge, M.A.;Wall, V.J.;Vernon, R.H.
  5. Journal of Geophysical Research v.89 High fluid pressures during regional metamorphism and deformation: implications for mass transport and deformation mechanisms Etheridge, M.A.;Wall. V.J.;Cox. S.F.;Wernon, R.H.
  6. Geolgical Magazine v.112 Textural patterns of porphyroblast margins and their use in determining the time relations of deformation and crystallization Ferguson,C.C.;Harte, B.
  7. Ore Geology Reviews v.2 Principles involved in mobilization and remobilization Hobbs, B.E.
  8. M.Sc. thesis, Acadia University, Wolfville, Nova Scotia Geology and metamorphism in the Port Mouton-Lockeport area, Queens and Shelburne Counites, Nava Scotia Hope, T.H.
  9. Ph.D. thesis, U.N.B., Fredericton The structural and metamorphic geology of the Shelburne area, Nava Scotia Hwang, S.G.
  10. Program With Abstracts v.10 Metamorphic development of southern Nova Scotia. Geological Association of Canda/Mineralogical Association of Canada Raeside, R.P.;White, C.E.;Wentzell, B.D.
  11. M.S. thesis, Virginia Polytechnic University and State University Variable water pressure metamorphic assemblages in the Meguma Grop, Nova Scotia Sage, J.D.
  12. United States Geological Survey Bulletin v.1562 High alumina hydrothermal systems in volcanic rocks and their significance to mineral prospecting in the Garolina Slate Belt. Schmidt, R.G.
  13. Ore Geology Reviews v.2 Evidence for movement of ore materials during high grade metamorphism Skinner, B.J.;Johnson, C.A.
  14. Journal of Metamorphic Geology v.13 Large-scale fluid infiltrtion, metasomatism nd re-equilibration of Archean basement granulites during Palaeoproterozoic therust belt construction St-Ongo, M.R.;Lucas, S.B.
  15. Reviews in Mineralogy v.10 Compositional zoning and inclusions in metamorphic minerals In Characterization ofmetamorphism therough mineral equilibria Tracy, R.J.;J.M. Ferry(ed)
  16. Geologische Rundschau. v.67 Porphyroblast-matrix microstructural relationships in deformed metamorphic rocks Vernon, R.H.
  17. B. Sc thesis, Acadia University The transition from staurolite to sillimanite zone, Port Latour, Nova Scotia. Wentzell, B.D.
  18. B.Sc thesis, Acadia University Structure and metamorphism of the Jordan River Valley, Shelburne county. Nova Scotia White, C.E.
  19. Journal of Structural Geology v.7 Multiply deformed terrainsproblems of correlation Williams, P.F.