La Chilca Formation
From Wikipedia, the free encyclopedia
La Chilca Formation (Spanish: Formación La Chilca) is a geological formation that crops out in the Precordillera of San Juan Province, Argentina. Rocks of the formation are mostly shale and sandstone that deposited during the Ordovician and Silurian periods.[1] The formation contains a high diversity of graptolite fossils.[1][2] Graptolite fossil taxa found include:[1]
