Diagénesis de bajo grado en los sedimentos de la Formación de Qumtanaloma (Cretácico Superior, Norte de Burgos, España): evidencias en la materia orgánica

Abstract

Several remains of wood and roots from the sediments of Quintanaloma Formation have been studied in order to determine the degree of organic evolution by measuring the huminite reflectance. Diagenesis of the organic matter linked to the rudist shells is limited to the precipitation of pyrite in crystals and framboids.

The reflectance values and the type of recognized macerals in the organic fraction: huminite (humotelinite and humocollinite) and liptinite (mainly resinite) suggest that the organic matter in the analysed samples is clearly immature. Thus, the organic evolution corresponds to diagenesis stage in the range from lignite to lignite/sub-bituminous coal. Other criteria supporting this idea are: the excellent preservation of original textures and details of vegetal tissues, the low-grade of gellification, compaction and homogenisation of tissues, and the intense fluorescence of resinite in the short wavelength domain with colours from green to yellowish green