Abstract

Detecting life evidences in other planetary bodies requires a deep knowledge of the variety of biomarkers that we could ever find there. On the planetary search of life, carbonates are of special interest to scientists due to often being associated to life. On Earth, they are valuable paleogeochemical archives containing fossils of up to billions of years. Here, we investigate the biomarkers profile on three Chilean Triassic-Jurassic sedimentary records searching for signs of past and present life over ~200 Ma. The combined identification of preserved proteins plus positive LDChip inmunodetections provided metabolic information and taxonomic affiliation of modern/subrecent biosignatures. Molecular and isotopic analysis of more perdurable lipids allowed identifying general biosources and dominant autotrophic pathways further back in time, as well as recreating prevailing redox conditions over ~200 Ma. We demonstrate how extraterrestrial life detection can benefit from using different biomarkers to overcome diagnosis limitations due to lack of specificity and/or alteration over time. This finding has implications for defining future astrobiological missions to Mars.