Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Chemical Zoning in Garnets from Rocks around the Massive Sulfide Deposits at Ducktown, Tennessee, and Its Implications

Sunit Kumar Addy and Peter J. M. Ypma
The Journal of Geology
Vol. 86, No. 3 (May, 1978), pp. 385-392
Stable URL: http://www.jstor.org/stable/30061990
Page Count: 8
  • Read Online (Free)
  • Download ($19.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Chemical Zoning in Garnets from Rocks around the Massive Sulfide Deposits at Ducktown, Tennessee, and Its Implications
Preview not available

Abstract

Garnets from the alteration zones and the country rocks surrounding the massive sulfide deposits at Ducktown, Tennessee, show strong compositional zoning of Mn and Fe and occasionally that of Ca and Mg. Observed continuous decrease of Mn (and Ca) and continuous increase of Fe (and Mg) from the core to the edge of crystals indicate that the mineral has been formed during prograde metamorphic events. Previous study shows that the minerals in the alteration zones, including garnet, are depleted in their $\delta^{18}O$ values by approximately 2 per mil compared to the country rocks. Since the compositional zoning of garnet indicates no recrystallization at a later time, it is concluded that garnets in the alteration zones were developed during the regional metamorphism in contact with an isotopically lighter hydrothermal solution which influenced the rocks surrounding the ore body. The study does not favor a post-metamorphic emplacement of the sulfides and the subsequent formation of the alteration zones.

Page Thumbnails

  • Thumbnail: Page 
385
    385
  • Thumbnail: Page 
386
    386
  • Thumbnail: Page 
387
    387
  • Thumbnail: Page 
388
    388
  • Thumbnail: Page 
389
    389
  • Thumbnail: Page 
390
    390
  • Thumbnail: Page 
391
    391
  • Thumbnail: Page 
392
    392