Pebas Formation

Summary

The Pebas Formation is a lithostratigraphic unit of Miocene age, found in western Amazonia. The formation extends over 1,000,000 square kilometres (390,000 sq mi), including parts of Brazil, Peru, Ecuador and Colombia.[1] It is interpreted as representing the deposits of a lake ("Lake Pebas") or series of lakes, formed within the foreland basin of the Andes mountain belt. It is known for its abundant fossil ostracods and molluscs and an unusually diverse group of crocodylians.[2]

Pebas Formation
Stratigraphic range: Early Aquitanian-Tortonian
(Colhuehuapian-Huayquerian)
~21–8 Ma
The Pebas Mega-Wetland (or Lake Pebas), on the western side of this map, corresponds to the Pebas Formation
UnderliesMarañón Formation
OverliesChambira Formation
Area1,000,000 km2 (390,000 sq mi)
Thickness~350–1,074 m (1,148–3,524 ft)
Lithology
PrimarySiltstone, mudstone
OtherCoal/lignite
Location
Coordinates7°24′S 75°00′W / 7.4°S 75.0°W / -7.4; -75.0
Approximate paleocoordinates8°24′S 70°36′W / 8.4°S 70.6°W / -8.4; -70.6
RegionAmazon Basin
Country Brazil
 Colombia
 Ecuador
 Peru
Type section
Named forPebas District

Fossil content edit

Group Fossils Notes
Mammals Dinomyidae indet., ?Octodontoidea indet.
Reptiles Caiman wannlangstoni, Gnatusuchus pebasensis, Gryposuchus pachakamue, Purussaurus neivensis, Kuttanacaiman iquitosensis, Mourasuchus atopus, Paleosuchus sp., Podocnemis sp., Gavialoidea indet.
Fishes cf. Hydrolycus sp., Leporinus sp., Potamotrygon sp., Pristis sp., Anostomidae indet.
Insects Macroteleia yaguarum, Sycorax peruensis

Correlations edit

Laventan edit

Laventan correlations in South America
Formation Honda Honda Aisol Cura-Mallín Pisco Ipururo Pebas Capadare Urumaco Inés Paraná Map
Basin VSM Honda San Rafael Caldera Pisco Ucayali Amazon Falcón Venezuela Paraná
Pebas Formation (South America)
Country   Colombia   Bolivia   Argentina   Chile   Peru   Venezuela   Argentina
Boreostemma      
Hapalops      
Miocochilius      
Theosodon      
Xenastrapotherium      
Mylodontidae        
Sparassodonta    
Primates  
Rodents              
Birds      
Terror birds  
Reptiles              
megalodon      
Flora  
Insects  
Environments Fluvial Fluvio-deltaic Fluvio-lacustrine Fluvio-deltaic Fluvial
  Laventan volcanoclastics

  Laventan fauna

  Laventan flora
Volcanic Yes

Huayquerian edit

Huayquerian correlations in South America
Formation Cerro Azul Ituzaingó Paraná Camacho Raigón Andalhuala Chiquimil Las Flores Maimará Palo Pebas Muyu Rosa Saldungaray Salicas Urumaco Map
Basin Colorado Paraná Hualfín Tontal Andes Salta Amazon Huasi Altiplano BA Velasco Falcón
Pebas Formation (South America)
Country   Argentina   Uruguay   Argentina   Brazil
  Peru
  Bolivia   Argentina   Venezuela
Cardiatherium        
Lagostomus            
Macroeuphractus      
Proeuphractus        
Pronothrotherium    
Pseudotypotherium      
Thylacosmilus      
Xotodon        
Macraucheniidae            
Primates  
Rodents                      
Reptiles            
Birds        
Terror birds      
Flora    
Environments Aeolian-fluvial Fluvio-deltaic Fluvial Fluvio-lacustrine Fluvial Fluvio-lacustrine Fluvio-deltaic
  Huayquerian volcanoclastics

  Huayquerian fauna

  Huayquerian flora
Volcanic Yes

References edit

  1. ^ Wesselingh et al., 2006
  2. ^ Sala Gismondi et al., 2006
  3. ^ a b c CTA-45 at Fossilworks.org
  4. ^ IQ114 at Fossilworks.org
  5. ^ Amazonian amber at Fossilworks.org

Bibliography edit

  • Montoya A., Diana M.; Diego Alonso O.; Alejandro Pinilla O., and José E. Arenas M. 2011. Geología de las Planchas 567, 568, 568bis, 569 and 569bis - 1:200,000, 1–187. Servicio Geológico Colombiano. Accessed 2018-06-01.
  • Salas Gismondi, R.; J.J. Flynn; P. Baby; J.V. Tejada Lara; F.P. Wesselingh, and P-O. Antoine. 2015. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands. Proceedings of the Royal Society B: Biological Sciences 282. 20142490. Accessed 2018-05-20.
  • Wesselingh, F.P.; M.C. Hoorn; J. Guerrero; M.E. Räsänen; L. Romero Pittmann, and J. Salo. 2006. The stratigraphy and regional structure of Miocene deposits in western Amazonia (Peru, Colombia and Brazil), with implications for late Neogene landscape evolution. Scripta Geologica 133. 291–322. Accessed 2017-08-15.

Further reading edit

  • Antoine, P.; J.A. Abello; S. Adnet; A.J. Altamirano Sierra; P. Baby; G. Billet; M. Boivin; Y. Calderón, and A.R. Candela and J. Chabain, F. Corfu, D. A. Croft, M. Ganerød, C. Jaramillo, S. Klaus, L. Marivaux, R. E. Navarrete, M. J. Orliac, F. Parra, M. E. Pérez, F. Pujos, J. Rage, Anthony Ravel, Céline Robinet, Martin Roddaz, Julia Victoria Tejada Lara, Jorge Vélez-Juarbe, Frank P. Wesselingh and Rodolfo Salas Gismondi. 2016. A 60-million-year Cenozoic history of western Amazonian ecosystems in Contamana, eastern Peru. Gondwana Research 31. 30–59. Accessed 2020-03-19.
  • Marcos C.Bissaro-Júnior, Leonardo Kerber, James L.Crowley, Ana M.Ribeiro, Renato P.Ghilardi, Edson Guilherme, Francisco R.Negri, Jonas P.Souza Filho, Annie S.Hsiou: "Detrital zircon U–Pb geochronology constrains the age of Brazilian Neogene deposits from Western Amazonia." Palaeogeography, Palaeoclimatology, Palaeoecology Volume 516, 15 February 2019, Pages 64–70 doi: 10.1016/j.palaeo.2018.11.032