Apón Formation

Apón Formation
Stratigraphic range: Early Cretaceous (Late Aptian)
Type	Geological formation
Sub-units	Machiques Member
Underlies	Aguardiente Formation
Overlies	Río Negro Formation
Lithology
Primary	Limestone, marl
Other	Calcareous and sandy shales
Location
Coordinates	10°57′30″N 71°38′50″W / 10.95833°N 71.64722°W / 10.95833; -71.64722
Approximate paleocoordinates	7°42′N 41°06′W / 7.7°N 41.1°W / 7.7; -41.1
Region	La Guajira, Maracaibo Basin
Country	Colombia, Venezuela
Type section
Named for	Apón River
Apón Formation (Venezuela)

The Apón Formation is a geological formation in northwestern Venezuela (Maracaibo Basin) and northern Colombia (La Guajira),^[1] whose thick-bedded limestone interbedded with subordinate amounts of dark gray calcareous shale and sandy shale strata date back to the Early Cretaceous (Late Aptian epoch).^[2] Pterosaur remains of Ornithocheiridae indet. (=?Anhangueridae indet.) are among the fossils that have been recovered from the formation.^[3]

The following fossils, among others, have been found in the Apón Formation at Toas island: Spiroculina sp., Orbitolina concava, Gryphaeostrea, Amphidonte (Ceratostreon) boussingaulti, Ostrea sp., Amphitriscoelus waringi, Requienia sp., Parahoplites sp., Cheloniceras sp., Quinqueloculina sp., Triloculina sp.,^[2] and Panopea (Myopsis) plicata in Río Negro.^[4]

• List of pterosaur-bearing stratigraphic units

• Barrett, P.M.; Butler, R.J.; Edwards, N.P.; Milner, A.R. (2008), Pterosaur distribution in time and space: an atlas. pp.61-107. in Flugsaurier: Pterosaur papers in honour of Peter Wellnhofer. Hone, D.W.E., and Buffetaut, E. (eds) (PDF), vol. 28, Zitteliana B, pp. 1–264, retrieved 2017-03-31
• García González, Mario; Mier Umaña, Ricardo; Cruz Guevara, Luis Enrique (2010), "Reconstrucción de la historia paleotermal de la subcuenca de la Baja Guajira, Colombia", Boletín de Geología, 32, retrieved 2017-03-31