Tecomazuchil Formation

The Tecomazuchil Formation is a geologic formation in Mexico. It preserves fossils dating back to the Jurassic period. It's made up of "a basal conglomerate 135 m thick and predominantly composed of quartz and metamorphic rock fragments, overlain by about 600 m of interbedded tan to red conglomerates, sandstones, and siltstones. The Tecomazuchil Formation overlies unconformably the Acatlán Complex and has been assigned a Middle Jurassic age, though it could represent at least part of the Oxfordian."