Otuma paleolagoon as potential for reconstruction of Pisco paleoceanographic conditions

Abstract

The geomorphology of Otuma paleolagoon is described; it calcareous records preservation and potential for paleoceanographic and paleoecology reconstruction were assessed. A low sea cliff and a soft slope abrasion platform with sand and gravel as dominant substrates suggests a shallow subtidal bottom 3.5 m deep at 80 m off shore. The distribution of calcareous records in-situ over the paleolagoon bottom suggests an ecological zonation pattern. The abundance of Argopecten purpuratus proves its dominance and the existence of a very productive natural bank of this bivalve, the shells showed a length distribution from 40 mm to 140 mm. The degree of preservation of the shells allowed an analysis of growth rings or lines, and the reconstruction of the species growth rhythm and pattern which are valuable to the reconstruction of environment variability.