Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Nyerereite-pirssonite-calcite-shortite relationships in altered natrocarbonatites, Oldoinyo Lengai, Tanzania. / Zaitsev, Anatoly N.; Keller, Jörg; Spratt, John; Perova, Elena N.; Kearsley, Anton.
в: Canadian Mineralogist, Том 46, № 4, 01.08.2008, стр. 843-860.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Nyerereite-pirssonite-calcite-shortite relationships in altered natrocarbonatites, Oldoinyo Lengai, Tanzania
AU - Zaitsev, Anatoly N.
AU - Keller, Jörg
AU - Spratt, John
AU - Perova, Elena N.
AU - Kearsley, Anton
PY - 2008/8/1
Y1 - 2008/8/1
N2 - Samples of natrocarbonatite showing various degrees of alteration are preserved in an older carbonatite platform that existed before and until the 1917 explosive eruption at Oldoinyo Lengai volcano, in Tanzania. The carbonatite samples contain two mineral assemblages: the first consists of relict primary magmatic minerals: nyerereite, fluorite, apatite-(CaF), barite, magnetite and khanneshite. The second consist of low-temperature subsolidus minerals: pirssonite, calcite, shortite, nahcolite, trona, thermonatrite, jacobsite and barytocalcite. Observed relationships between key primary and subsolidus minerals show the following sequence of formation: nyerereite → pirssonite → calcite → shortite. Three major processes, mineral dissolution, metasomatic replacement and crystallization from solution, alter the natrocarbonatite to pirssonite carbonatite, shortite carbonatite and calcite carbonatite. Nyerereite - pirssonite - calcite relationships depend on variations in P(H2O) and P(CO2).
AB - Samples of natrocarbonatite showing various degrees of alteration are preserved in an older carbonatite platform that existed before and until the 1917 explosive eruption at Oldoinyo Lengai volcano, in Tanzania. The carbonatite samples contain two mineral assemblages: the first consists of relict primary magmatic minerals: nyerereite, fluorite, apatite-(CaF), barite, magnetite and khanneshite. The second consist of low-temperature subsolidus minerals: pirssonite, calcite, shortite, nahcolite, trona, thermonatrite, jacobsite and barytocalcite. Observed relationships between key primary and subsolidus minerals show the following sequence of formation: nyerereite → pirssonite → calcite → shortite. Three major processes, mineral dissolution, metasomatic replacement and crystallization from solution, alter the natrocarbonatite to pirssonite carbonatite, shortite carbonatite and calcite carbonatite. Nyerereite - pirssonite - calcite relationships depend on variations in P(H2O) and P(CO2).
KW - Brines
KW - Calcite
KW - Metasomatic
KW - Natrocarbonatite
KW - Nyerereite
KW - Oldoinyo Lengai
KW - Pirssonite
KW - Replacement
KW - Shortite
KW - Solutions
KW - Tanzania
UR - http://www.scopus.com/inward/record.url?scp=56649088068&partnerID=8YFLogxK
U2 - 10.3749/canmin.46.4.843
DO - 10.3749/canmin.46.4.843
M3 - Article
AN - SCOPUS:56649088068
VL - 46
SP - 843
EP - 860
JO - Canadian Mineralogist
JF - Canadian Mineralogist
SN - 0008-4476
IS - 4
ER -
ID: 28660829