Tecomazuchil Formation

{{Infobox rockunit

| name = Tecomazuchil Formation

| image =

| caption =

| type = Geological Formation

| age = {{fossilrange|Callovian}}

| period = Callovian

| prilithology = Silty Sandstone{{cite web|title=3 Ayuquililla (Jurassic of Mexico)|url=https://paleobiodb.org/classic/displayCollResults?collection_no=24679|website=FossilWorks|access-date=17 December 2021}}

| otherlithology =

| namedfor =

| namedby = * Rafael Pérez-Ibarguengoitia

• Antonio Hokuto-Castillo
• Alencaster de Cserna

| region = Puebla Province

| country = Mexico

| coordinates =

| unitof =

| subunits =

| underlies = Chimeco Limestone

| overlies = Acatlán Complex

| thickness =

| extent =

| area =

| map =

| map_caption =

}}

The Tecomazuchil Formation is a geologic formation in Oaxaca, Mexico. It is 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."{{cite book|last1=Westermann|first1=Gerd E. G.|title=The Jurassic of the Circum-Pacific|date=1992|publisher=Cambridge University Press|isbn=0521019923|page=100|url=https://books.google.com/books?id=iMus4MtzIl4C&q=Tecomazuchil+Formation&pg=PA100|accessdate=5 April 2017}} Fossil Bennettitales have been found in the formation.{{Cite journal|date=2021-06-01|title=Weltrichia xochitetlii sp. nov. (Bennettitales) from the Middle Jurassic of northwestern oaxaca, Mexico: First paleobotanical evidence from the Tecomazúchil Formation|url=https://www.sciencedirect.com/science/article/abs/pii/S0895981121000778|journal=Journal of South American Earth Sciences|language=en|volume=108|pages=103230|doi=10.1016/j.jsames.2021.103230|issn=0895-9811|last1=Lozano-Carmona |first1=Diego E. |last2=Corro-Ortiz |first2=Marcos Germán |last3=Morales |first3=René Luis |last4=Velasco-De León |first4=María Patricia |s2cid=234085434 |url-access=subscription}}