| Evergreen Formation | |
|---|---|
| Stratigraphic range: Lower Pliensbachian- Late Toarcian ~[1] | |
| Type | Geological formation |
| Unit of | Bundamba Group |
| Sub-units | Boxvale Sandstone & Westgrove Ironstone Members |
| Underlies | Hutton Sandstone |
| Overlies | Precipice Sandstone |
| Thickness | Up to 255 m (837 ft) |
| Lithology | |
| Primary | Sandstone, siltstone, mudstone |
| Other | Coal, ironstone |
| Location | |
| Coordinates | 25°48′S 150°18′E / 25.8°S 150.3°E |
| Approximate paleocoordinates | 61°42′S 90°00′E / 61.7°S 90.0°E |
| Region |  New South Wales Queensland |
| Country |  Australia |
| Extent | |
| Type section | |
| Named for | "Evergreen Shales" |
| Named by | Hogetoorn[3] |
  Evergreen Formation (Australia) | |
The Evergreen Formation is a Pliensbachian to Toarcian geologic formation of the Surat Basin in New South Wales and Queensland, eastern Australia. Traditionally it has been considered to be a unit whose age has been calculated in between the Pliensbachian and Toarcian stages of the Early Jurassic, with some layers suggested to reach the Aalenian stage of the Middle Jurassic, yet modern data has found that an Early Pliensbachian to Latest Toarcian age is more possible.[4][5][6] The formation was named due to the "Evergreen Shales", defined with a lower unit, the Boxvale Sandstone, and a partially coeval, partially younger upper unit, the Westgrove Ironstone Member.[7] This unit overlies the Hettangian-Sinemurian Precipice Sandstone, as well several informal units such as the Nogo Beds, and Narayen beds, as well Torsdale Volcanics.[7] This unit likely was deposited in a massive lacustrine body with possible marine environment influences.[8]
- ^ La Croix, Andrew D.; Sobczak, Kasia; Esterle, Joan S.; Bianchi, Valeria; Wang, Jiahao; He, Jianhua; Hayes, Phil; Underschultz, Jim R.; Garnett, Andrew (2022). "Integrating palynostratigraphy with zircon geochronology in the Lower Jurassic Precipice Sandstone and Evergreen Formation to improve stratigraphic correlation within the Great Artesian Basin, Australia". Marine and Petroleum Geology. 144 (4): 56–89. Bibcode:2022MarPG.14405845L. doi:10.1016/j.marpetgeo.2022.105845. ISSN 0264-8172.
- ^ Waschbusch, P.; Korsch, R.J.; Beaumont, C. (2009). "Geodynamic modelling of aspects of the Bowen, Gunnedah, Surat and Eromanga Basins from the perspective of convergent margin processes". Australian Journal of Earth Sciences. 56 (3): 309–334. Bibcode:2009AuJES..56..309W. doi:10.1080/08120090802698661. Retrieved 31 May 2023.
- ^ Hogetoorn, D.J. (1967). "Jurassic reservoirs of the Surat Basin". World Petroleum Congress. 7: 161–170. Retrieved 31 May 2023.
- ^ "Australian Government- Geoscience Australia Australian Stratigraphic Units Database". ga.gov.au. Geoscience Australia. Retrieved 19 January 2015.
- ^ Todd, Christopher N.; Roberts, Eric M.; Knutsen, Espen M.; Rozefelds, Andrew C.; Huang, Hui-Qing; Spandler, Carl (December 2019). "Refined age and geological context of two of Australia's most important Jurassic vertebrate taxa (Rhoetosaurus brownei and Siderops kehli), Queensland". Gondwana Research. 76: 19–25. Bibcode:2019GondR..76...19T. doi:10.1016/j.gr.2019.05.008.
- ^ Sobczak, Kasia; La Croix, Andrew D.; Esterle, Joan; Hayes, Phil; Holl, Heinz-Gerd; Ciesiolka, Rachael; Crowley, James L.; Allen, Charlotte M. (2022). "Geochronology and sediment provenance of the Precipice Sandstone and Evergreen Formation in the Surat Basin, Australia: Implications for the palaeogeography of eastern Gondwana". Gondwana Research. 111: 189–208. Bibcode:2022GondR.111..189S. doi:10.1016/j.gr.2022.08.003. ISSN 1342-937X.
- ^ a b Withnall, I. W.; Hutton, L. J.; Bultitude, R. J.; Von Gnielinski, F. E.; Rienks, I. P. (2009). "Geology of the Auburn Arch, southern Connors Arch and adjacent parts of the Bowen Basin and Yarrol Province, central Queensland". Queensland Geology. 12 (2): 13–32. Retrieved 31 May 2023.
- ^ Martin, M.; Wakefield, M.; Bianchi, V.; Esterle, J.; Zhou, F. (2017). "Evidence for marine influence in the Lower Jurassic Precipice Sandstone, Surat Basin, eastern Australia". Australian Journal of Earth Sciences. 65 (1): 75–91. doi:10.1080/08120099.2018.1402821. Retrieved 31 May 2023.