Biochemical Markers In Geological Samples.Application In Paleo-Environmental Reconstruction

Biochemical markers or molecular fossils trapped in geological materials provide unmatchable information regarding the environment, climate, and biota of the past on Earth. This review formally integrates recent developments and varied applications of these organic molecules in paleo-environmental reconstruction. With emphasis on publications from 2020 and later, we discuss key biomarker classes such as different lipid biomarkers (n-alkanes, hopanoids, sterols, GDGTs, alkenones), pigments, and amino acids, describing their origin, preservation, and proxy value for parameters like paleotemperature, redox, hydrological cycles, and productivity of ecosystems.The advances in high-resolution analysis methods combined with improved proxy calibration in recent years have greatly improved the accuracy and range of biomarker applications. The key results emphasize the strength of multi-proxy methods, the selectivity of molecular markers in recognizing microbial communities, and their vital application in reconstructing important past events such as Oceanic Anoxic Events and continental climatic changes. Although diagenetic challenges and source uncertainty exist, continued research is refining these methods further. The review highlights the pivotal role played by biochemical markers in contemporary paleo-sciences, enhancing fundamental context regarding long-term Earth system behavior and guiding future environmental prediction. Keywords: Biochemical Markers, Molecular Fossils, Paleo-Environmental Reconstruction, Organic Geochemistry, Lipids, Paleoclimate, Proxy.