Définition/Signification de mya

• English - Symbol: mya million year s ago : megayear s ago. 2015, Joyce A. Quinn, Susan L. Woodward, “Introduction”, in Earth's Landscape: An Encyclopedia of the World's Geographic Features, volumes I: A–L, Santa Barbara, CA: ABC-CLIO, →ISBN, page xxxi: The first (oldest) unit of time is the Precambrian Supereon, which covers much of Earth's history from its origins roughly 4.55 bya to 545 mya . Very primitive,…