Microestructuras, diagénesis y evidencias estacionales en las valvas de Crassostrea sp. del Albiense superior-Cenomaniense inferior en la playa de Somocuevas (Liencres, Cantabria)

Abstract

The microstructural and cathodoluminescence (CL) study of Crassotrea sp. shells of Somocuevas, Cantabria (Upper Albian-Lower Cenomanian) has allowed to determinate that the dominant diagenetic process involved in the shells has been freatic meteoric, with cementación process in the pores and preservation of the initial microstructure of the oysters. The main microstructures are: Regular simple prismatic (RSP), Regular foliated (RF) and Complex cross foliated (CCF). These microstructures present a variable luminescence. The RSP exhibits a yellow-bright luminescence. The RF is not luminescent or presents a dull red luminescence, and the CCF has a medium to bright yellow luminescence. It is also observable the presence of dark growth lines with yellow bright luminescence in the RF, that are related with fractures in the umbo zone. It is proposed that these zones indicate anual growth lines that can be used to determinate seasonality