TITLE:
Spinel-Bearing Lherzolite Xenoliths from Hosséré Garba (Likok, Adamawa-Cameroon): Mineral Compositions and Geothermobarometric Implications
AUTHORS:
Nguihdama Dagwai, Chazot Gilles, Kamgang Pierre, Mbowou Gbambié Isaac Bertrand, Ngounouno Ismaïla
KEYWORDS:
Xenoliths, lherzolite, Geothermobarometry, Likok, Adamawa
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.12,
November
18,
2014
ABSTRACT: Spinel-bearing
lherzolite xenoliths from the Hossere Garba (1272 m.a.s.l) volcano on the Adamawa
Plateau, is located in Likok village, at about 35 km to WSW of Ngaoundere. These
xenoliths (~11 cm size) have been sampled into the host basaltic lava flows from
the NE flank of the Hossere Garba volcano. These xenoliths characterized by porphyroclastic
texture consisted of olivine (~55 vol.%), orthopyroxene (~19 vol.%) and clinopyroxene
(~21 vol.%) crystals. Spinel crystals (~5 vol.%) are red brown and interstitial
between the crystals of olivine and pyroxenes. CaO contents are low (VI/AlIV ratio range between 1.1 and 1.3 for
the Cr-diopside crystals from Hossere Garba xenoliths. The constant value of the
volumes V(Cell) and V(M1) for clinopyroxene compositions, indicates the similar
pressures. Hossere Garba represents a residual sequence issued from partial melting
of a mantle source. Similar compositions have been recorded in minerals of ultramafic
xenoliths from other ultramafic xenoliths domains of the Cameroon Line and the Adamawa
Plateau.