The Aledjo Quartzitic Ruins in Northern Togo: Genesis and Structural Geomorphology

Ms Tairou,Be Sabi,N Simpara,P Affaton,F Boudzoumou,Pyd Da Costa

doi:10.4314/gjgs.v10i2.5

Abstract

In northern Togo, the Aledjo Mountains represent a NE-SW to ENE-WSW trending segment of the Pan-African Dahomeyide orogen. This mainly quartzitic topography belongs to the external zone of the belt and, more precisely, to the eastern assemblage of the Atacora Structural Unit. It corresponds to a ruiniform landscape which resulted from an erosive sculpturing that started at the end of the Pan-African tectogenesis within the Dahomeyide Belt, at about 550 Ma. A first interpretation of these spectacular sculptures attributed their great variety to predisposition factors related to the petrographic heterogeneity of the quartzites and to the Pan-African tectogenesis. With reference to these genetic factors, the Aledjo quartzitic ruins are subdivided into two morphostructural groups related either to a combination of folding and erosion or fracturing and erosion. Moreover, the Aledjo ruiniform landscape may be considered as an attractive touristic target which can contribute to regional economic development in northern Togo. Keywords: Quartzitic Ruins, Aledjo Montains, Dahomeyide, Northern Togo, Morphogenesis

Highlights

The quartzites of the Aledjo Mountains display spectacular ruiniform landscapes made up of numerous and varied natural sculptures
The Aledjo Mountains form part of the quartzitic Atacora sub-unit (Noel et al, 1984; Sylvain et al, 1986; Tairou, 1995). It is an anticlinorial megastructure overtrusted, in the North, by the orthogneissic Kara-Niamtougou nappes and, in the South-East, by the meta-volcanosedimentary assemblage of the Sokode-Kemeni Unit (Tairou, 1995, THE ALEDJO QUARTZITIC RUINS IN NORTHERN TOGO: 2006)
This study is intended as a contribution to the development of the tourist potential of these numerous natural monuments. Such a valorization of the geological patrimony agrees with the objectives of the “Association for the protection of the natural patrimony of the Aledjo Mountains” (APANAMA) which has as its ambition the inclusion of the Aledjo Mountains in the national or sub-regional touristic circuit

Summary

INTRODUCTION

The quartzites of the Aledjo Mountains display spectacular ruiniform landscapes made up of numerous and varied natural sculptures. These curious or mysterious sculptures are little or not at all known, apart from the famous “Aledjo Fault” which is exposed along a major international road. 1 – Geographic Framework The Aledjo Mountains stretch between longitudes 1° and 1°25’E and latitudes 9°10’ and 9°20’N They display a picturesque NE-SW to ENE-WSW trending landscape in northern Togo (Fig. 1a). The temperature in the Aledjo Mountains is very variable (2035°C) during the year These mountains correspond to a part of the watershed between the huge Mono and Oti basins. Da Costa, Département de Géologie, Faculté des Sciences, Université de Lomé, BP 1515 Lomé, Togo

Mylonitic zone of Kandi Fault Thrusting contact

The ruiniform landscapes of the Aledjo