Smith, M.P., Henderson, Paul and Jeffries, Teresa (2002) The formation and alteration of allanite in skarn from the Beinn an Dubhaich granite aureole, Skye European Journal of Mineralogy, 14 (3). pp. 471-486. ISSN 0935-1221Full text not available from this repository.
Allanite-(Ce) occurs as a metasomatic phase in diopside-hedenbergite-anorthite-hastingsite endoskarn from the Beinn an Dubhaich granite aureole, Skye. Fluid-inclusion studies indicate formation of pyroxene at temperatures in the range 600-700oC from Na-K-Fe-Ca bearing brines(45-60wt.%NaCl eq.) assuming pressures of 280-640 bars. Allanite and amphibole formed at much lower temperatures (230-250oC) from low- to moderate-salinity fluids(~ 0-15wt % NaCl eq.) High F contents in both amphibole and vesuvianite indicate that the fluids were F bearing at all stages in the paragenesis. Allanite has textures resulting from growth and alteration. Britholite-(Y) occurs as either a discrete phase, or as an alteration product of allanite. LA-ICP-MS analyses demonstrate that whilst Th remained relatively constant in individual allanite grains, U was leached during alteration. The Th content does vary with zonation, however, and may be altered by processes such as over-growth. The hydrothermal mobility of the REE and Th was almost certainly a result of high-F contents in the hydrothermal fluids. The hydrothermal formation and alteration of allanite may have important consequences for geochronological studies of other allanite occurrences.
|Item Type:||Journal article|
|Uncontrolled Keywords:||allanite, Rare Earth Elements, skarn, fluid inclusions|
|Subjects:||F000 Physical Sciences > F600 Geology|
|DOI (a stable link to the resource):||10.1127/0935-1221/2002/0014-0471|
|Faculties:||Faculty of Science and Engineering > School of Environment and Technology > Applied Geosciences
Faculty of Science and Engineering > School of Environment and Technology
|Depositing User:||editor environment|
|Date Deposited:||30 Mar 2007|
|Last Modified:||21 Mar 2013 02:18|
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