Dorotea Formation | |
---|---|
Stratigraphic range: Late Campanian-Maastrichtian ~72–66 Ma
| |
Type | Geological formation |
Underlies | Man Aike Formation |
Overlies | Tres Pasos Formation |
Thickness | 100–350 m (330–1,150 ft) |
Lithology | |
Primary | Sandstone, claystone |
Other | Conglomerate |
Location | |
Coordinates | 50°42′S 72°30′W / 50.7°S 72.5°W / -50.7; -72.5 |
Approximate paleocoordinates | 52°54′S 60°30′W / 52.9°S 60.5°W / -52.9; -60.5 |
Region | Magallanes Region |
Country | Chile |
Extent | Río de Las Chinas Valley, Magallanes Basin |
Type section | |
Named for | Sierra Dorotea |
Named by | Katz |
Year defined | 1963 |
Dorotea Formation (Chile) |
The Dorotea Formation is a geological formation in the Río de Las Chinas Valley of the Magallanes BasininPatagonian Chile whose strata date back to the CampaniantoMaastrichtian of the Late Cretaceous.[1]
The Dorotea Formation was first described by Katz in 1963. The formation comprises sandstones with frequent conglomerate lenses, concretionary levels and claystones. The Dorotea Formation includes calcareous sandstones with abundant marine invertebrate and fragmentary vertebrate fossils. Hervé et al. (2004) obtained a maximum radiometric age of 67.4 ± 1.5 Ma from detrital zircons contained in sandstones of the Dorotea Formation.[2]
The mudstones and sandstones of the formation were deposited in a fluvial environment. The formation conformably overlies the Tres Pasos Formation and is unconformably overlain by the LutetiantoBartonian Man Aike Formation.[3] The thickness of the formation ranges from 100 metres (330 ft) in the Sierra Baguales in the north to 350 metres (1,150 ft) in the eponymous Sierra Dorotea in the south.[4]
The following fossils were reported from the formation:[5]
Amphibians of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Anura[6] | Indeterminate | A frog |
Reptiles of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Aristonectinae[7] | Indeterminate | |||
Aristonectes | Aristonectes sp.[7] | |||
Yaminuechelys | cf. Yaminuechelys sp.[6] | |||
Panchelidae[6] | Indeterminate | |||
Elasmosauridae | Indeterminate |
Dinosaurs of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Enantiornithes[8] | Indeterminate | |||
Gonkoken[9] | G. nanoi | Several incomplete specimens belonging to individuals of different ages | Ahadrosauroid | |
Megaraptoridae[8] | Indeterminate | |||
Ornithischia[6] | Indeterminate | |||
Ornithurae[8] | Indeterminate | |||
Sauropoda[6] | Indeterminate | |||
Stegouros | S. elengassen | CPAP-3165 (holotype), a holotype consists of a relatively complete skeleton with a skull and lower jaws. | Aparankylosaur | |
Unenlagiinae[8] | Indeterminate | |||
Theropoda[6][8] | Indeterminate |
Mammals of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Magallanodon[10] | M. baikashkenke[10] | Agondwanathere | ||
Orretherium | O. tzen[11] | Amesungulatid mammal | ||
Mammalia[6] | Indeterminate |
Fish of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Ischyrhiza | I. chilensis[4] | |||
Carcharias | C. sp.[4] | |||
Serratolamna | Indeterminate[4] |
Invertebrates of Dorotea Formation | ||||
---|---|---|---|---|
Taxa | Species | Material | Notes | Images |
Dorotheus | Dorotheus guidensis[12] | |||
Pterotrigonia | P. cazadoriana[2] | |||
Gunnarites | G. sp.[2] | |||
Pachydiscus | P. aff. gollevilensis[2] |
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