The San Juan Formation ( Spanish : Formación San Juan ) is a geologic formation in Argentina . The formation comprising limestones , mudstones and marls was deposited in a shallow marine reefal environment and preserves many fossils dating back to the Ordovician period . The formation overlies the La Silla Formation and crops out in the Precordillera of San Juan Province .
3-672: San Juan Formation may refer to: San Juan Formation, Argentina , an Ordovician geologic formation in Argentina San Juan Formation, Mexico , an Eocene geologic formation in Mexico San Juan Raya Formation , an Albian geologic formation in Mexico San Juan Terrace Formation , a Pleistocene geologic formation in Peru Topics referred to by
6-483: Is different from Wikidata All article disambiguation pages All disambiguation pages San Juan Formation, Argentina The oldest calcareous microfossils , known as calcisphers or calcitarchs , were found in the Early Ordovician ( Floian ) strata of this formation. Trilobites , gastropods and echinoderm Nuia sibiria have been collected from the same deposits. This article about
9-432: The same term [REDACTED] This disambiguation page lists articles associated with the title San Juan Formation . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=San_Juan_Formation&oldid=858529806 " Category : Disambiguation pages Hidden categories: Short description
#439560