The type locality of the Candeleros Formation is Candeleros Hill in Neuquén Province, after which the formation was named by Wichmann in 1929.[2] This formation unconformably overlies the Lohan Cura Formation, and it is fused with the Huincul Formation, also a unit of the Neuquén Group. The sediments of the latter are of lighter greenish and yellow colors and the fused boundary between the Candeleros and Huincul formations is easily recognizable.[3]
The Candeleros Formation is almost 300 metres (980 ft) thick in some sections. Overall, the formation represents a part of the ancient Kokorkom desert with braided river system, made up mostly of sandstones and conglomerates. There are also isolated sections that represent eolian (wind-blown) deposition, as well as siltstones deposited under swamp conditions. Paleosols (soil deposits) are common in some sections as well.[1][3]
The Candeleros Formation has a very diverse fossil fauna, including fish, frogs, mammals, rhynchocephalians, snakes, turtles, notosuchians, pterosaurs, and abundant dinosaurs including rebbachisaurid and titanosaurian sauropods and diverse theropods, and the enigmatic armored Jakapil.
^Baez, Ana & Trueb, Linda & Calvo, Jorge. (2000). The earliest known pipoid frog from South America: A new genus from the Middle Cretaceous of Argentina. Journal of Vertebrate Paleontology. 20. 490-500. 10.1671/0272-4634(2000)020%5B0490:TEKPFF%5D2.0.CO;2.
^Lerzo, Lucas N.; Fernández-Baldor, Fidel Torcida; Canale, Juan I.; Whitlock, John A.; Otero, Alejandro; Gallina, Pablo A. (2024-08-13). "They all floated in the Cretaceous: new rebbachisaurid (Sauropoda, Diplodocoidea) with a highly pneumatized skeleton from the Upper Cretaceous (lower Cenomanian) of Patagonia, Argentina". Historical Biology: 1–14. doi:10.1080/08912963.2024.2383708. ISSN0891-2963.
^Maniel, I.J.; de la Fuente, M. S.; Zhuo, J.I. (2021). "The first Cearachelyini (Pelomedusoides, Bothremydidae) turtle from the Upper Cretaceous of Patagonia, and an overview of the occurrence and diversity of Pelomedusoides in Patagonia". Cretaceous Research. 125: Article 104869. Bibcode:2021CrRes.12504869M. doi:10.1016/j.cretres.2021.104869.
Wichmann, R (1929). "Los Estratos con Dinosaurios y su techo en el este del Territorio del Neuquén ("The dinosaur-bearing strata and their upper limit in eastern Neuquén Territory")". Dirección General de Geología, Minería e Hidrogeología Publicación. 32: 1–9.