First luminescence geochronology of the beach-dune ridges of Nayarit strand-plain (west-central Mexico)

Abstract

Strand-plains are composed by beach-dune ridges that constitute coastal sedimentological records of continental erosion and associated climatic and geological controls on their formation. The strand-plain of Nayarit is one the most prominent strand-plains around the world as it is composed by > 250 well-preserved beach-dune ridges that distributes along >200 km between the states of Nayarit and Sinaloa (west-central Mexico) and extends for ∼14 km inland. Although the strand-plain of Nayarit is of broad interest for understanding the evolution of Quaternary landscapes, it has remained understudied. To contribute to a better understanding of the landscape evolution of the strand-plain of Nayarit we present here a complete geochronology based on sixteen OSL dating ages distributed across three different transects of beach-dune ridges located from the coast towards the inland. Our data indicate that in all cases the oldest ridges initiated ∼2 ka. The depositional rates range from ∼6 m a −1 toward the south of the strand-plain, where is located the mouth of Santiago and San Pedro rivers, which are the largest of the study area, to ∼1.8 m a −1 toward the north. These depositional rates are among the highest denudation rates reported in strand-plains around the world. We estimate that the formation of the coastal plain of Nayarit initiated ∼6 to 7 ka, which correspond to last period of the global marine stabilization after sea level rise.