Research output: Contribution to journal › Article › peer-review
Carbonatites from the Oldoinyo Lengai volcano, northern Tanzania, are unstable under normal atmospheric conditions. During carbonatite interaction with water the major minerals gregoryite Na 2 (CO 3 ), nyerereite Na 2 Ca(CO 3 )2 and sylvite KCl are dissolved and replaced by secondary low-temperature minerals thermonatrite Na 2 (CO 3 )·H 2 O, trona Na3(CO 3 )(HCO 3 )·2H 2 O, nahcolite Na(HCO 3 ), pirssonite Na 2 Ca(CO 3 )2 ·2H 2 O, calcite Ca(CO 3 ) and shortite Na 2 Ca 2 (CO 3 )3. Thermodynamic calculations show that the formation of secondary minerals within Oldoinyo Lengai carbonatites are controlled by pH of pore solution, H 2 O and CO 2 fugacity and the ratio of Ca and Na activities in the system Na 2 O-CaO-CO 2 -H 2 O.
Original language | English |
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Pages (from-to) | 1-13 |
Number of pages | 13 |
Journal | Zapiski Rossiiskogo Mineralogicheskogo Obshchestva |
Volume | 145 |
Issue number | 3 |
State | Published - 1 Jan 2016 |
ID: 42298879