Author(s)

Nguihdama Dagwai^1*, Chazot Gilles², Kamgang Pierre³, Mbowou Gbambié Isaac Bertrand⁴, Ngounouno Ismaïla⁴

¹Ecole Normale Supérieure, Université de Maroua, Maroua, Cameroun.
²Université Européenne de Bretagne, Brest, France.
³Département des sciences de la Terre, Faculté de Sciences, Université de Yaoundé I, Yaoundé, Cameroun.
⁴Ecole de Géologie et d’Exploitation Minière (EGEM), Département de Mines et de la Géologie, Université de Ngaoundéré, Meiganga, Cameroun.

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 (<0.08 wt%) in olivine and similar to those estimated (CaO: 0.05 - 0.1 wt%) for the mantle origin. The values of Al^VI/Al^IV 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.

Xenoliths, lherzolite, Geothermobarometry, Likok, Adamawa

Dagwai, N. , Gilles, C. , Pierre, K. , Bertrand, M. and Ismaïla, N. (2014) Spinel-Bearing Lherzolite Xenoliths from Hosséré Garba (Likok, Adamawa-Cameroon): Mineral Compositions and Geothermobarometric Implications. International Journal of Geosciences, 5, 1435-1444. doi: 10.4236/ijg.2014.512117.