Primeval Civilizations in the Geological Record: Implications for Detecting Technosignatures Across Worlds
To the point
It explores the possibility that civilizations could have existed before Homo sapiens and how long-lasting traces like plastics, metals, electronics residues, or carbon-isotope signals might survive for hundreds of millions of years, be hard to detect because the fossil record is sparse, and inform how we search for technosignatures on other worlds.
