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the other two are from Mohanpur and Satyanarayanpur, respectively. Both are from
the Raniganj Basin. The analyses of these rocks are given in Table
13.2
. Experi-
mental studies on these lamproites are summarized below.
13.2.6.1 P
-
T Study on a Phase Relation in a Jarangdih Lamproite
Experimental results on the Jarangdih sample are summarized in Fig.
13.9
(for
chemical analyses of the lamproites from Jarangdih, Mohanpur and Satyanara-
yanpur see Table
13.2
), which shows that olivine is the liquidus phase in the P-T
T
range of this study. With lowering of temperature following assemblages succes-
sively, appear:
-
Ol
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Opx
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Opx
þ
Il
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Opx
þ
Ap
þ
Il
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Opx
þ
Ap
þ
Il
þ
Cb
þ
Liq
þ
Vap
!
Ol
þ
Phl
þ
Opx
þ
Ap
þ
Il
þ
Cb
þ
Vap
:
Below the solidus, the assemblage corresponds to a Mg-ilmenite, apatite and
carbonate-bearing phlogopite harzburgite. It is interesting to note that although
Fig. 13.9 Phase relations of a olivine lamproite from Jarangdih coal mine (Bokaro Basin). For
abbreviations, see Appendix I (after Gupta et al. 2002). apat: apatite, opx: orthopyroxene, ilm:
ilmenite, liq: liquid, phl: phlogopite, carb: carbonatite, liq: liquid, vap: vapour
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