Geological and Petrographic Factors Affecting Formation of Active Landslides in the North of Biga Peninsula, NW Turkey

Abstract

The study includes landslide movements that take place on Eocene and Middle-Upper Miocene aged the terrestrial and marine sedimentary rock units on the Canakkale basin in the Biga Peninsula. In this study, the active Ambaroba Landslide, Şevketiye and Adatepe Landslides located on the northern coasts of Biga Peninsula were investigated.The geological studies in the Ambaroba landslide have shown the integrity of the Bayramiç formation and the Şapcı volcanics in this area have shown their influence in the Miocene period.The sandstones in the Bayramiç formation are not very well paste and are yellow, dirty yellow and gray in color.The sliding surface units in the moving masses consist of non-hardening, very large blocky, pebbly and loose cement-bonded pebbles. In the Şevketiye and Adatepe Landslides, a sliding movement has occurred on the sandstone and conglomerate units with yellowish brown colors in the Fıçıtepe formation. The sandstones in these landslide areas are massive and well cemented. Conglomerates are weaker than sandstones and are fond of a gray-beige color that does not harden. Precipitation data and GPS measurements of the landslide areas were evaluated together with the lithological properties of the rocks.Loose sandstones and pebbles in the entire landslide areas studied can easily move due to seasonal precipitation.This movement was mostly seen in the Şevketiye landslide area and then in the Adatepe and Ambaroba areas, respectively. Although their effectiveness has decreased, the movements will continue, as the lithological features will not change in these areas. As a result, the measures specified in this study should be taken into account in order to eliminate the destructive effects of landslides.