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Meyer Desert Formation
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| Meyer Desert Formation | |
|---|---|
| Stratigraphic range: | |
 Meyer Desert Formation exposed in the Oliver Bluffs on the flanks of the Beardmore Glacier | |
| Type | Geological formation |
| Unit of | Sirius Group |
| Overlies | Cloudmaker Formation |
| Thickness | 185 m (607 ft) |
| Lithology | |
| Primary | Diamictite, sandstone, siltstone |
| Other | Peat, marlstone |
| Location | |
| Coordinates | 85°07′S 166°35′E / 85.117°S 166.583°E |
| Region | Transantarctic Mountains, Meyer Desert, Dominion Range |
| Country | Antarctica |
| Extent | Oliver Bluffs, Beardmore Glacier region |
| Type section | |
| Named for | Meyer Desert |
| Named by | McKelvey et al., 1991 |
The Meyer Desert Formation is a glacigenic, mostly non-marine sedimentary sequence that forms the upper part of the Sirius Group in the central Transantarctic Mountains. It is notable for containing the youngest known macrofossils of terrestrial plants and palaeosols found anywhere in Antarctica, preserved at elevations of ~1,760 m above sea level and approximately 500 km from the South Pole. Some earlier works included it within a broader “Sirius Formation,” but this usage has been largely abandoned.[1]
Biota
[edit]
The Meyer Desert Formation at Oliver Bluffs preserves a short-lived Pliocene interglacial tundra.[1] Mean summer temperatures reached ~4–5 °C for 1–2 months, with 24-hour daylight, permafrost, strong katabatic winds, very low precipitation, and a growing season of only 6–12 weeks.[1][2][3]
The landscape was a low-relief, gravelly braided outwash plain with unstable moraines, scattered shallow ponds, and thin peat lenses. Vegetation consisted of prostrate Nothofagus shrubs, dense vascular cushion plants up to 30 cm across, moss hummocks, scattered buttercups, sedges, and rare mare's-tail in wet hollowss.[1][3] This setting was similar to the windswept cushion Bush and fellfields of Patagonia and Tierra del Fuego above 800–1000 m, but also to highland modern Tasmania and New Zealand.[3]
Fossil Nothofagus leaves show that intermittent warm periods allowed Nothofagus shrubs to cling to the Dominion Range as late as 3-4 Ma (mid-late Pliocene).[2] After that the Pleistocene glaciation covered the whole continent with ice and destroyed all major plant life on it.[4] Tought more recent data records similar floras at least until the Miocene in the Antarctic Peninsula.[5]
Animals
[edit]| Genus | Species | Affinity / Family | Image |
|---|---|---|---|
| Antarctotrechus[6] | balli | Carabidae |  |
| Curculionidae[7] | "Morphotype 1" | Listroderini (aff. Listroderes) |  |
| "Morphotype 2" | Listroderini (aff. Falklandius/Telurus) |  | |
| Cyclorrhapha[8] | Indet. | aff. Cochliomyia |  |
| Lymnaeidae[9] | Indet. | aff. Chilina |  |
| Osteichthyes[3] | Indet. | Freshwater taxon | |
| Ostracod[10] | Indet. | Putatively non-marine ostracods | |
| Pisidium[9] | sp. | Sphaeriidae |  |
Plants
[edit]| Genus | Species | Affinity / Family | Image |
|---|---|---|---|
| Cushion plants[3] | Indet. | Donatiaceae, Apiaceae, Caryophyllaceae or Asteraceae | |
| Cyperaceae[3] | "Morphotype 1" | Sedges | |
| "Morphotype 2" | Sedges | ||
| Hippuris[3] | sp. | Hippuridaceae |  |
| Marchantiaceae[3] | Indet. | Liverwort | |
| Nothofagidites[3] | (Fuscospora) lachmaniae | Nothofagaceae (cf. Nothofagus) |  |
| Nothofagus[11] | beardmorensis | Nothofagaceae (aff. Nothofagus gunnii) | |
| Poaceae[3] | Indet. | Grass | |
| Podocarpidites[3][12] | "sp. b" | Podocarpaceae (Aff. Pilgerodendron or Lepidothamnus) |  |
| Pottiaceae[3] | Indet. | Moss, other 4 unnamed types are found | |
| Ranunculus[3] | sp. | Ranunculaceae |  |
| Reniform seed[3] | Indet. | ?Chenopodiaceae, ?Caryophyllaceae or ?Myrtaceae | |
| Tricolpites[12] | sp. | Polygonaceae or Lamiaceae | |
| "sp. 2" | Polygonaceae or Lamiaceae |
References
[edit]- ^ a b c d Rees-Owen, Rhian L.; Gill, Fiona L.; Newton, Robert J.; Ivanović, Ruza F.; Francis, Jane E.; Riding, James B.; Vane, Christopher H.; Lopes dos Santos, Raquel A. (2018-04-01). "The last forests on Antarctica: Reconstructing flora and temperature from the Neogene Sirius Group, Transantarctic Mountains". Organic Geochemistry. 118: 4–14. Bibcode:2018OrGeo.118....4R. doi:10.1016/j.orggeochem.2018.01.001. hdl:10023/12701. ISSN 0146-6380.
- ^ a b Retallack, G. J.; Krull, E. S.; Bockheim, J. G. (2001). "New grounds for reassessing palaeoclimate of the Sirius Group". Journal of the Geological Society, London. 158 (6): 925–35. doi:10.1144/0016-764901-030. S2CID 128906475.
- ^ a b c d e f g h i j k l m n Ashworth, Allan C.; Cantrill, David J. (2004-10-07). "Neogene vegetation of the Meyer Desert Formation (Sirius Group) Transantarctic Mountains, Antarctica". Palaeogeography, Palaeoclimatology, Palaeoecology. 213 (1): 65–82. doi:10.1016/j.palaeo.2004.07.002. ISSN 0031-0182.
- ^ Stefi Weisburd (March 1986). "A forest grows in Antarctica. (an extensive forest may have flourished about 3 million years ago)". Science News. Retrieved 2012-11-02.
- ^ Bastias-Silva, Joaquin; Leppe, Marcelo; Manriquez, Leslie; Trevisan, Cristine; Fox, Bethany R. S.; Magiera, Matthias; Wilson, Gary; Tavazzani, Lorenzo; Chelle-Michou, Cyril; Gao, Liang; Szymanowski, Dawid; Mansilla, Héctor; Silva, Carolina; Hervé, Francisco; Tapia, Claudio (2025-11-26). "Neogene plant macrofossils from West Antarctica reveal persistence of Nothofagaceae forests into the early Miocene". Communications Earth & Environment. 6 (1): 965. doi:10.1038/s43247-025-02921-x. ISSN 2662-4435.
- ^ Ashworth, Allan C.; Erwin, Terry L. (2016-11-23). "Antarctotrechus balli sp. n. (Carabidae, Trechini): the first ground beetle from Antarctica". ZooKeys (635): 109–122. Bibcode:2016ZooK..635..109A. doi:10.3897/zookeys.635.10535. ISSN 1313-2970. PMC 5126512. PMID 27917060.
- ^ Ashworth, Allan C; Kuschel, Guillermo (2003-02-15). "Fossil weevils (Coleoptera: Curculionidae) from latitude 85°S Antarctica". Palaeogeography, Palaeoclimatology, Palaeoecology. 191 (2): 191–202. Bibcode:2003PPP...191..191A. doi:10.1016/S0031-0182(02)00712-5. ISSN 0031-0182.
- ^ Ashworth, Allan C.; Thompson, F. Christian (2003). "A fly in the biogeographic ointment". Nature. 423 (6936): 135–136. doi:10.1038/423135a. ISSN 1476-4687.
- ^ a b Ashworth, Allan C.; Preece, Richard C. (2003). "The first freshwater molluscs from Antarctica". Journal of Molluscan Studies. 69 (1): 89–92. doi:10.1093/mollus/69.1.89. ISSN 1464-3766.
- ^ Williams, Mark; Siveter, David J; Ashworth, Allan C; Wilby, Philip R; Horne, David J; Lewis, Adam R; Marchant, David R (2008-07-22). "Exceptionally preserved lacustrine ostracods from the Middle Miocene of Antarctica: implications for high-latitude palaeoenvironment at 77 south". Proceedings of the Royal Society B: Biological Sciences. 275 (1650): 2449–2454. Bibcode:2008PBioS.275.2449W. doi:10.1098/rspb.2008.0396. PMC 2603191. PMID 18647723.
- ^ Hill, R. S.; Harwood, D. M.; Webb, P. -N. (1996-11-01). "Nothofagus beardmorensis (Nothofagaceae), a new species based on leaves from the Pliocene Sirius Group, Transantarctic Mountains, Antarctica". Review of Palaeobotany and Palynology. 94 (1): 11–24. Bibcode:1996RPaPa..94...11H. doi:10.1016/S0034-6667(96)00003-6. ISSN 0034-6667.
- ^ a b Askin, R.A.; Markgraf, V. (1986). "Palynomorphs from the Sirius Formation, Dominion Range, Antarctica" (PDF). Antarc. J. U.S. 21 (5): 34–35.