HR: 0800h
AN: V41E-1511 [Abstracts]
TI: Using of Correlating monomineral thermobarometry for mantle peridotites (correlating
methods).
AU: * Ashchepkov, I V
EM: Igor.Ashchepkov@uiggm.nsc.ru
AF: United Institute of Geology Geophysics and Mineralogy SD RAS, Koptyug ave 3, Novosibirsk, 630090
Russian Federation
AU: Pokhilenko, N P
EM: cheif@uiggm.nsc.ru
AF: United Institute of Geology Geophysics and Mineralogy SD RAS, Koptyug ave 3, Novosibirsk, 630090
Russian Federation
AU: Sobolev, N V
EM: Sobolev@uiggm.nsc.ru
AF: United Institute of Geology Geophysics and Mineralogy SD RAS, Koptyug ave 3, Novosibirsk, 630090
Russian Federation
AU: Rotman, A Y
EM: rotman@cnigri.alrosa-mir.ru
AF: Central Science and Research Geology And Prospecting Institute Of The Stock Company "ALROSA",
Chernyshevsky Str,7, Mirny, 678170
Russian Federation
AU: Afanasiev, V P
EM: morpho@uiggm.nsc.ru
AF: United Institute of Geology Geophysics and Mineralogy SD RAS, Koptyug ave 3, Novosibirsk, 630090
Russian Federation
AU: Afanasiev, V P
EM: morpho@uiggm.nsc.ru
AF: Central Science and Research Geology And Prospecting Institute Of The Stock Company "ALROSA",
Chernyshevsky Str,7, Mirny, 678170
Russian Federation
AU: Logvinova, A M
EM: logv@uiggm.nsc.ru
AF: United Institute of Geology Geophysics and Mineralogy SD RAS, Koptyug ave 3, Novosibirsk, 630090
Russian Federation
AU: Vladykin, N V
EM: vlad@igc.irk.ru
AF: Institute of Geochemistry SD RAS, Favorsky str. 1a, Irkutsk, 664033
AU: Kostrovitsky, S I
EM: sercos@igc.irk.ru
AF: Institute of Geochemistry SD RAS, Favorsky str. 1a, Irkutsk, 664033
AU: Karpenko, M A
EM: karmenko@alrosa-aihal.ru
AF: Aykhal Mining Enterprise of Stock Company "ALROSA, Almazny str., 3-26, Aykhal, 678170
AU: Vishnyakova, E V
EM: vishnyakova_ev@nkmk.ru
AF: Novokuznetsk metallurgical enterprise, Kurako 1, Novokuznetsk, 670000
AB:
Correlating monomineral thermobarometry using kimberlite mega- and xenocrysts and xenoliths allows to determine mantle
layering with concentrate from kimberlites or placers. Orthopyroxene method (Brey, Kohler,1990)-(McGregor, 1974) was used for
calibration of others. Clinopyroxene. Po =0.04*Kd *ToC/(1-2.4*Fe)-5.5 where KD = Na/Ca *Mg/(Al+Cr)and polynomial P =
0.00006*Po3 - 0.0156*Po2 + 1.6757*Po (R2 = 0.8245). The ToC (Nimis -Taylor, 2000) are corrected ToC= 000001*TooC**2
+0.9575*TooC+107.01 Garnet. Thermometers based on: 1) OPx's (Brey, Kohler,1990) estimates, ToC =5272.5*(Ln(KD)/P)3+10265*
(Ln(KD)/P)2+ 6472* Ln(KD)/P +2113 where KD= MgO*TiO2/((CaO+MgO)2* FeO*Al2O3 2) CPx (Nimis, Taylor, 2000), : T0oC
=362.05*(Ln(KD)/P)3+1880.4* (Ln(KD))/P2+2659.6* Ln(KD)/P +1695.5 where KD= Na2O*MnO*TiO2/(CaO+MgO)* FeO*Al2O3, 3) Gar-Cpx
(Krogh, 1988) KD= Na2O*MnO*TiO2/(CaO+MgO)* FeO*Al2O3, 4)Ni in garnet thermometry (Griffin, 1989) with Ni(ppm)
=88,877*E**(-5.021*Ni'), (R2=0.69) where Ni' =MnO*ln(FeO)/ln(MgO)*1.1-0.193*TiO2 +0.003*ln(Na2O)-
0.003*Cr2O3+0.0035*CaO+0.004*Al2O3 ToC =0.0004*Ni3-0.0304*Ni2 +7.6318*Ni+ 597.2 ( R2 = 0.69) Chromite P=0.86347*(Cr/(Cr+Al)*
ToC/14+Ti*0.1) the second approximation P=0.0004*Po3-0.0342*Po2+1.5323*Po The temperatures are determined using monomineral
version of the Ol-Sp thermometer (Taylor et al.,1998) Fo=0.06+0.0005*P for P >30 kbar and Fo=0.095+0.0001*Po for the lower
pressures. The Sp-Ol oxybarometer (Taylor et al ., 1998) give the lineal correlation with monomineral version made in the
same manner (R-0,96). Ilmenite. P= (TiO2-23.)*2.15-(ToC-700)/20*MgO*Cr2O3-1.5*MnO)*ToC/1273 and further P=10*(60-Po)/60+Po.
Monomineral version Ol-Il thermometer (Taylor et al ., 1998) where Fo=0.11+0.00025*P for pressures lower then 30 kbar and
Fo=0.10+0.00025*P for greater pressures. The monomineral fO2 oxybarometer same Fo content . Data for 7 kimberlite fields in
Yakutia show large scale variations of the mantle different part of Siberian platform
DE: 1000 GEOCHEMISTRY
DE: 1009 Geochemical modeling (3610, 8410)
DE: 1025 Composition of the mantle
DE: 1037 Magma genesis and partial melting (3619)
DE: 1065 Major and trace element geochemistry
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005