6533b86dfe1ef96bd12ca7fa
RESEARCH PRODUCT
Modeling of retrograde diffusion zoning in garnet: evidence for slow cooling of granulites from the Highland Complex of Sri Lanka
L. P. BaumgartnerC. A. HauzenbergerW. HofmeisterG.w.a.r. Fernandosubject
ProterozoicMetamorphic rockGeochemistryengineering.materialGranuliteGondwanaGeophysicsBasement (geology)Geochemistry and PetrologyengineeringMaficZoningBiotiteGeologydescription
¶Diffusion modeling of zoning profiles in garnet rims from mafic granulites is used to estimate cooling rates in the Proterozoic basement of Sri Lanka, which represents a small, but important fragment of the Gondwana super-continent. Metamorphic peak temperatures and pressures, estimated with two-pyroxene thermometry and garnet–clinopyroxene–plagioclase–quartz (GADS) barometry, yield 875±20 °C and 9.0±0.1 kbar. These peak metamorphic conditions are slightly higher than results obtained by garnet-biotite Fe–Mg exchange thermometry of 820±20 °C. Reset flat zoning profiles were observed in most garnets. Only narrow garnet rims touching biotite exhibit retrograde zoning in terms of Fe and Mg exchange.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2003-04-01 | Mineralogy and Petrology |