Gatuncillo Formation
{{distinguish|Gatún Formation}}
{{Infobox rockunit
| name = Gatuncillo Formation
| image =
| caption =
| type = Formation
| age = Middle-Late Eocene
| period = Bartonian
| prilithology = Mudstone, siltstone
| otherlithology = Limestone, sandstone, conglomerate
| namedfor = Gatuncillo River
| namedby = Thompson
| year_ts = 1944
| region = Panamá Province
| country = Panama
| coordinates = {{coord|9.3|N|79.7|W|display=inline,title}}
| paleocoordinates = {{coord|6.8|N|77.3|W|display=inline}}
| unitof =
| subunits =
| underlies = Caimito, Bohío & Panama Formations
| overlies = Cretaceous basement
| thickness = {{convert|150|-|800|m|ft|abbr=on}}
| extent = Panama Basin
| area =
| map = {{Location map+ | Panama
| relief = 1
| width = 250
| float = center
| places =
{{Location map~ | Panama
| lat_deg = 9.3
| lon_deg = -79.7
| mark = Orange pog.svg
| marksize = 12
}}
}}
| map_caption =
}}
The Gatuncillo Formation (Tgo)Geologic Map, 1980 is a geologic formation in central Panama. The formation is exposed in the Panama Canal Zone and surrounding areas. It preserves fossils dating back to the Middle to Late Eocene period.[https://paleobiodb.org/classic/displayStrata?geological_group=&formation=Gatuncillo&group_formation_member=Gatuncillo Gatuncillo Formation] at Fossilworks.org
Description
The Gatuncillo Formation is the oldest sedimentary unit of the Panama Canal Zone, unconformably resting on Cretaceous basement. The formation was defined as Gatuncillo Shale by Thompson in 1944, who named it after the Gatuncillo River. The estimated thickness ranges from {{convert|150|to|800|m|ft}}.Woodring, 1957, p.13
Though the Gatuncillo consists chiefly of mudstone and siltstone, it includes bentonitic mudstone, sandstone, and limestone, and at the base a conglomerate of variable thickness.Woodring, 1957, p.14
Fossil content
See also
References
{{reflist|20em}}
= Bibliography =
- {{citation |last1=Cadena |first1=E. |last2=Bourque |first2=J.R. |last3=Rincón |first3=A.F. |last4=Bloch |first4=J.I. |author5-link=Carlos Jaramillo (geologist) |last5=Jaramillo |first5=C.A. |last6=MacFadden |first6=B.J. |year=2012 |title=New turtles (Chelonia) from the late Eocene through Late Miocene of the Panama Canal Basin |url=https://www.researchgate.net/publication/233777124 |journal=Journal of Paleontology |volume=86 |issue=3 |pages=539–557 |doi=10.1666/11-106.1 |bibcode=2012JPal...86..539C |accessdate=2019-02-09 |author1-link=Edwin Cadena }}
- {{citation |last1=Erdei |first1=Boglárka |last2=Calonje |first2=Michael |last3=Hendy |first3=Austin |last4=Espinoza |first4=Nicolas |year=2018 |title=A review of the Cenozoic fossil record of the genus Zamia L. (Zamiaceae, Cycadales) with recognition of a new species from the late Eocene of Panama - evolution and biogeographic inferences |url=http://www.geology.cz/bulletin/fulltext/1671_Erdei_180719.pdf |journal=Bulletin of Geosciences |volume=93 |issue=2 |pages=185–204 |doi=10.3140/bull.geosci.1671 |accessdate=2019-02-09}}
- {{citation |last1=Stewart |first1=R.H. |last2=Stewart |first2=J.L. |last3=Woodring |first3=W.P. |year=1980 |title=Geologic Map of the Panama Canal and Vicinity |url=https://pubs.usgs.gov/pp/0306f/plate-1.pdf |publisher=USGS |pages=1 |accessdate=2019-02-09}}
- {{citation |last=Woodring |first=W.P |year=1957 |title=Geology and Paleontology of Canal Zone and Adjoining Parts of Panama - 306A Geology and description of Tertiary mollusks (Gastropods: Trochidae to Turritellidae) |url=https://pubs.usgs.gov/pp/0306a/report.pdf |publisher=USGS |pages=1–186 |accessdate=2019-02-09}}
Category:Geologic formations of Panama
Category:Conglomerate formations of Panama
Category:Shallow marine deposits