Estratigrafía molecularlos biomarcadores como indicadores de cambios climáticos y ambientales en la historia del Sistema Tierra

Abstract

Biomarkers are organic molecules that are found in sediments and sedimentary rocks and contain information about their precursor organisms and their sedimentary environments. They are “molecular informants” containing valuable clues about the history of Earth. Biomarkers record the biological evolution along with the environmental history of Earth, and in recent years they have become powerful tools in Stratigraphy, contributing to the study and interpretation of the sedimentary record. This article reviews the fundamental concepts about biomarkers: main types, chemical and isotopic composition, origin, preservation and transformation processes, and basic analytical procedures. The second part focuses on their foremost applications: their use as proxies for biological origin, marine and continental productivity, oxygen content in marine water and sediments, and finally as paleoclimate archives (proxies for paleotemperatures and paleoconcentrations of atmospheric CO2).