TITLE:
Petrostructural and Geochemical Characteristics of the Metamagmatites in the External Zone of the Dahomeyides Belt: Case of the Kantè Serpentinites (Northern Togo)
AUTHORS:
Mahaman Sani Tairou, Yougbare Mariette Wennegouda Miningou, Yawoa Dzidzo Da Costa, Maurice Kwekam
KEYWORDS:
Tectogenesis, Microfabrics, Serpentinites, Panafrican, Northern Togo
JOURNAL NAME:
International Journal of Geosciences,
Vol.13 No.9,
September
22,
2022
ABSTRACT: Thanks to detailed field investigations, microstructural and geochemical
analysis and relationship with enclosing rocks, microfabrics, magmatic typology and
metamorphic evolution of the Kantè sepentinites have been specified for the
first time. The Kantè serpentinites in northern Togo constitute a mega-lens of
ultrabasic rocks tectonically intercalated in the sericite chlorite schists of
the Atacora structural unit. The brecciated, schitotose or massive rock facies
are strongly marked by an S1 schistocity plane superimposed by a flat C shear
plane linked to a west vergence thrusting movement. The parageneses that
compose the metamagmatites are essentially serpentinous, containing plagioclase,
opaque minerals (magnetite, chromite, spinel) and pyroxene porphyroblasts.
These microfabrics represent relics of a probable gabbroic protolith. In fact,
the geochemical characteristics of the Kantè serpentinites suggest that their
magmatic typology is that of komatiites or tholeiitic basalts with oceanic arc
affinities. They would have been emplaced in an active margin environment. The
retromorphic evolution of the protolith corresponds to the phase of involvement
in a major tangential contact during the panafrican tectogenesis.