Earth:Hornitos Formation
| Hornitos Formation Stratigraphic range: Late Cretaceous, Campanian–Maastrichtian | |
|---|---|
| Type | Geological formation |
| Lithology | |
| Primary | Limestone, sandstone, conglomerate |
| Other | Marl, tuff |
| Location | |
| Coordinates | [ ⚑ ] : 28°00′S 70°18′W / 28.0°S 70.3°W |
| Paleocoordinates | [ ⚑ ] 30°36′S 54°30′W / 30.6°S 54.5°W |
| Region | Atacama |
| Country |  Chile |
| Extent | Algarrobal Basin |
  Hornitos Formation (Chile) | |
The Hornitos Formation is a Campanian geologic formation of the Algarrobal Basin in the Atacama Region of northern Chile . The formation comprises limestones, sandstones, conglomerates, marls and tuff. Dinosaur remains are among the fossils that have been recovered from the formation, including the sauropod Arackar licanantay.[1]
Description
The Hornillos Formation, deposited in the Algarrobal Basin,[2] comprises sandstones, limestones, conglomerates, and caliches, intercalated with lavas and andesitic breccias and various volcanic rocks. Between these last is a conspicuous layer of rhyo-dactitic lithic tuff, which reaches up to 10 metres (33 ft) in thickness. Bones of indeterminate titanosaurs appear in a marly limestone stratum of 10 metres (33 ft) thick with decimeter-sized calcareous concretions. The smallest pieces were found as rollings, whereas the larger piece was included in the limestone.[3]
The Hornitos Formation formerly was thought to be of Paleocene to Eocene age.[4] The formation may be older and belong to the Early Cretaceous, as a granite intruded the rocks about 105 ± 10 Ma.[5]
See also
- List of dinosaur-bearing rock formations
- List of stratigraphic units with indeterminate dinosaur fossils
- Abanico Formation
References
Bibliography
- Abad E., Eduardo. 1982. [[1] Un modelo de depositación de uranio en la Cuenca de Algarrobal, Vallenar, Chile], 1–37. III Congreso Geológico Chileno. Accessed 2018-09-08.
- Rivano G., Sergio et al.. 1986. Antecedentes radiométricos para una edad cretácica inferior de la Formación Las Chilcas. Andean Geology 27. 27–32. Accessed 2018-09-08.
- Rivera Cabello, Sergio. 1985. [[2] Una discusión sobre la edad de las formaciones Cerrilos y Hornitos, Región de Atacama], 1–13. IV Congreso Geológico Chileno. Accessed 2018-09-08.
- Weishampel, David B.; Peter Dodson, and Halszka Osmólska (eds.). 2004. The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN:0-520-24209-2
Further reading
- G. Chong Diaz. 1985. Hallazgo de restos oseos de dinosaurios en la Formación Hornitos – Tercera Region de Atacama – Chile. IV Congreso Geologico Chileno 152-161
- P. Salinas, P. Sepúlveda, and L. G. Marshall. 1991. Hallazgo de restos oseos de dinosaurios (saurópodos) en la Formación Pajonales (Cretácico Superior), Sierra de Almeyda, Región de Antofagasta, Chile: implicancia cronológica [Discovery of skeletal remains of dinosaurs (sauropods) in the Pajonales Formation (Upper Cretaceous), Sierra de Almeyda, Antofagasta Region, Chile: chronological implications]. 6e Congreso Geológico Chileño, Viña del Mar. Resumenes Expandidos. Servicio Nacional de Geología y Mineria, Chile 534-537
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