Engineering geology of the Kannaviou, 'Melange' and Mamonia Complex formations : Phiti/Statos area, S W Cyprus : engineering geology of cohesive soils associated with ophiolites, with particular reference to Cyprus

This report describes the characteristic engineering properties and behaviour of the cohesive soils of, or derived from, the Kannaviou, Melange and Mamonia Complex Formations which occur in close proximity to the Troodos ophiolite in the Paphos region of SW Cyprus. The investigation was concentrated in two study areas centred on the villages of Phiti (Area 1) and Statos (Area 2), respectively,located in the landslide-prone highlands adjacent to the updomed Troodos Massif. An extensive geotechnical and mineralogical database of over 3000 discrete test data has been established derived from samples collected from surface outcrops, trial pit excavations and borehole drilling programmes in each study area. Geological and detailed landslide mapping was undertaken in each study area resulting in the preparation of two 1:10 000 scale engineering geology maps. The maps show that major slope stability problems occur where weak, sheared montmorillonitic clays and Melange deposits crop out on steep slopes in areas of high relief; with landslide development exacerbated by high winter rainfalls, permeable chalk and limestone caprocks, earthquake shocks and active erosion associated with continued uplift of Troodos.Limited analyses of slope angles and residual shear strength data indicate that limiting slope angles for shallow mass movements in the Kannaviou and Melange clays are c. 8.5 degrees and 11 degrees, respectively. Deep-seated slope failures are shown to be largely associated with faults. The report suggests a number of practical guidelines for engineering development and future investigations both in SW Cyprus and in similar ophiolite terrains elsewhere.