UNGRD

In: Colombia. Instituto de Investigaciones en Geociencias, Minería y Química (INGEOMINAS). Memorias. Santafé de Bogotá , Colombia. Instituto de Investigaciones en Geociencias, Minería y Química (INGEOMINAS), 1993. Presentado en: Congreso Colombiano de Geología, 6; Medellín, 13-16 jun. 1993. The Caribbean coastline of Chocó province is highly rocky with steep cliffs appearing in rectilinear segments. This model exhibits a strong structural influence through faulting and jointing which follow a principal NW-SE tendency and a secundary one NE-SW. A probable fault frings the shoreline in the studied area keeping a good parallelism with near faults located onshore and apparently offshore. An exception of the rocky outline of the Chocó shoreline are Acandi and La Playona zones which show low topography and are composed of fluvial and marine sediments. Because most of the litoral area is rocky the former marine processes including sea level fluctuations have left on the shoreline important related tracks. One of these remains is the 1.0. M wave cut platform which in the north sector was built on recent coral reef deposits, meanwhile the platform in the south part was developed on tertiary volcanic and sedimentary rocks. From the echo sounding profiles obtained during the field work in the littoral zone it is stablished that there are sumerged wave cut platforms close to the shoreline. In fact relics of one were identified al 20'. Other less extended platform remains appear at 30' and 70' below mean sea level. The study was not explicit enough to determine if the platforms were cut in the late Quaternary, as consequence of the recent eustatic sea level rise, or were derived from land uplift (AU). / COSTA CARIBE / CHOCO