Lashly Formation
The Lashly Formation is a Late Triassic (Carnian) geologic formation in Victoria Land of Antarctica. The formation has provided fossil flora and indeterminate reptiles and dicynodonts.
Lashly Formation Stratigraphic range: Carnian ~235–222 Ma | |
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Type | Geological formation |
Lithology | |
Primary | Sandstone, mudstone |
Other | Conglomerate, siltstone |
Location | |
Coordinates | 77.2°S 160.1°E |
Approximate paleocoordinates | 66.7°S 86.6°E |
Region | Victoria Land |
Country | Antarctica |
Lashly Formation (Antarctica) |
Tuff found in combination with Dicroidium fragments were interpreted as the result of a forest fire during the Triassic.[1]
Description
The Lashly Formation comprises carbonaceous mudstones and conglomeratic sandstones deposited in channels and on floodplains of a meandering fluvial environment.
Lashly member C consists of fining-upward cycles of medium- to fine-grained sandstone grading upward into carbonaceous siltstone and mudstone, and thin coal beds. Quartz pebbles and cobbles and mudstone clasts occur near the base of major sandstone units. Irregular lenses of coal occur along bedding planes and over large scours. Dicroidium fronds and other plant fragments are common in carbonaceous beds.[2]
Fossil content
The following fossils have been reported from the formation:[2][3]
- Therapsids
- Reptiles
- Flora
- Craterisporites rotundus
- Playfordiaspora crenulata
- Alisporites spp.
- Aratrisporites spp.
- Dicroidium sp.
- Uvaesporites spp.
References
- Kumar et al., 2011, p.33
- Lashly Formation at Fossilworks.org
- Hammer et al., 2004
Bibliography
- Kumar, Madhav; Rajni Tewari; Sankar Chatterjee, and Naresh C. Mehrotra. 2011. Charcoalified plant remains from the Lashly Formation of Allan Hills, Antarctica: Evidence of forest fire during the Triassic Period. Episodes 34. 33-42. Accessed 2020-06-18.
- Hammer, W.R.; J.W. Collinson; R.A. Askin, and W.J. Hickerson. 2004. The first Upper Triassic vertebrate locality in Antarctica. Gondwana Research 7. 199-204.