- journal_title：European Journal of Mineralogy
- Contributor：Lutz NASDALA ; Frank E. BRENKER ; Jürgen GLINNEMANN ; Wolfgang HOFMEISTER ; Tibor GASPARIK ; Jeffrey W. HARRIS ; Thomas STACHEL ; Ingo REESE
- Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
- Date：2003-
- Format：text/html
- Language：en
- Identifier：10.1127/0935-1221/2003/0015-0931
- journal_abbrev：Eur J Mineral
- issn：0935-1221
- volume：15
- issue：6
- firstpage：931
- section：Articles
We have studied high-pressure inclusions (Ca-silicates, coesite, graphite) in three large diamonds, one from the Kankan district, Guinea, and the other two from the Panda kimberlite, Ekati diamond mines, Canada. Using the in situ point-by-point mapping technique with a confocal Raman system, the mineralogy of the inclusions, as well as their area distribution pattern (e.g., of different Ca-silicate phases) and their order-disorder distribution pattern (shown for graphite/disordered carbon), were determined. Raman mapping of the host diamonds yielded 2D-tomographic pressure and strain distribution patterns and provided information on the residual pressure of the inclusions (∼ 2.3 GPa for a coesite inclusion and ∼ 2.6 GPa for a graphite inclusion). The inclusions are surrounded by haloes of significantly enhanced pressure, several hundred σm across. These haloes exhibit complex pressure relaxation patterns that consist of micro-areas affected by both compressive and dilative strain, with the latter being intensive enough to result in apparent “negative pressures”.