Sedimentology and morphology of the beach for nesting of marine turtles, El Carrizal, Coyuca of Benitez, Guerrero

From august 2007 to june 2009, ten topographic profiles were made on the Carrizal beach during rainy and dry seasons in order to determine the morphologic changes on beach profiles. Samples of sediments were collected in nearshore, onshore and backshore related to the beach profiles. The results show that the morphology of the beach zone near the mouth of the lagoon of Coyuca is more dynamic with high berms to 2 meters, strong slopes from 10 to 15 degrees and beaches are less than 45 meters in width. A major stability is finding in the farthest part of the lagoons mouth where profiles are accumulative and longger than 50 meters with soft slopes. The sediments are composed of quartz-phel-despatic sands, usually of medium size, well sorted and skewed to coarse sands and they are leptocurtic in beach face and in backshore, while in the nearshore they are skewed to coarse sizes.