TSK 11 Göttingen 2006 Kouankap
 Neotectonic markers in the
 Panafrican belt formations of
 Cameroon: elements of inter-
 pretation and their environ-
 mental impacts Poster
 Nono Gus D. Kouankap1
 The North equatorial Panafrican Belt,
 whose Cameroonian formations are
 dated between 650 and 400 million
 years, and which are located in the
 North of the Congo Craton, is subdi-
 vided in to three major geodynamic do-
 mains: a north Cameroon domain, a
 central Cameroon domain and a south
 Cameroon domain. These major do-
 mains are generally, particularly the
 central domain, affected by great strike-
 slip faults in which the most important
 are the central cameroonian shear zone
 and the Sanaga fault.
 Studies that establish the order of oc-
 currence of geological events, generally
 performed in these domains and partic-
 ularly at Banefo area (West Cameroon)
 reveal markers of recent tectonics (post
 panafrican) that affect the granitogneis-
 sic basement. They include:
 1. pseudotachytes observed in the re-
 gions of Yaoundé, Tibati, Edea,
 and Banefo (Fig. 1);
 2. Net and fresh stries of movement
 observed on the quartzofeldspathic
 injections sampled in some faults in
 the Banefo locality (Fig. 2).
 The impact of the repeated action of
 this fault on the environment is ex-
 pressed by:
 • the fissuration of the tarred road
 at the level of the Banefo road cut,
 1 Université de Yaoundé I, Départe-
 ment des Sciences de la Terre, BP : 812
 Yaoundé-Cameroun
 Figure 1: pseudotachylites
 in the same direction as the major
 fractures of this locality;
 • the crumbling of gneissified massifs
 in the Banefo Region in 1955, pre-
 ceeding a series of local minor earth
 tremors;
 • fissuration, in parallel directions, of
 houses in some urban areas of the
 Yaoundé town; capital of the Re-
 public of Cameroon (Fig. 3);
 Figure 2: Stries of movement.
 1
Kouankap TSK 11 Göttingen 2006
 Figure 3: Fissurations of the houses.
 • the most recent regional earth
 tremor (March 2005) recorded
 along the Sanaga Fault, which was
 registered right at Yaoundé situ-
 ated 70 km away from the fault.
 The tectonic processes that occur in the
 North Equatorial Panafrican belt since
 the end of panafrican orogeny (400My)
 to the present day can be explained in
 the context of the neotectonic processes.
 The causes of the neotectonics, accord-
 ing to Ngako (1999), might be due to
 the processes of progressive peneplana-
 tion of the Panafrican reliefs by erosion,
 thus controlling the mechanism of iso-
 static rising of the crust/mantle inter-
 face from the end of the orogeny.
 The genetic link existing between the
 pseudotachytes and the seismic faults
 coupled with the recorded minor earth
 tremors make the geotectonic environ-
 ment of these areas a non-aseismic one,
 and for this reason, a particular atten-
 tion should be focussed in the study of
 those major accidents in order to pre-
 dict, monitor and take the necessary
 measures to minimize the consequences
 of an eventual natural seismic catastro-
 phe in this environment which seems
 aseismic.
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