Meyer Desert Formation

Meyer Desert Formation
Stratigraphic range: Miocene or Pliocene PreꞒ Ꞓ O S D C P T J K Pg N
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′S166°35′E / 85.117°S 166.583°E / -85.117; 166.583
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

Tasmania highlands are a good analogue

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

Genus	Species	Affinity / Family	Image
Antarctotrechus [6]	balli	Carabidae	Antarctotrechus
Curculionidae [7]	"Morphotype 1"	Listroderini (aff. Listroderes )	Listroderes
	"Morphotype 2"	Listroderini (aff. Falklandius / Telurus )	Telurus dissimilis
Cyclorrhapha [8]	Indet.	aff. Cochliomyia	Cochliomyia
Lymnaeidae [9]	Indet.	aff. Chilina	Chilina
Osteichthyes [3]	Indet.	Freshwater taxon
Ostracod [10]	Indet.	Putatively non-marine ostracods
Pisidium [9]	sp.	Sphaeriidae	Pisidium

Plants

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	Hippuris
Marchantiaceae [3]	Indet.	Liverwort
Nothofagidites [3]	(Fuscospora) lachmaniae	Nothofagaceae (cf. Nothofagus )	Nothofagus gunnii
Nothofagus [11]	beardmorensis	Nothofagaceae (aff. Nothofagus gunnii )
Poaceae [3]	Indet.	Grass
Podocarpidites [3] [12]	"sp. b"	Podocarpaceae (Aff. Pilgerodendron or Lepidothamnus )	Pilgerodendron
Pottiaceae [3]	Indet.	Moss, other 4 unnamed types are found
Ranunculus [3]	sp.	Ranunculaceae	Ranunculus
Reniform seed [3]	Indet.	?Chenopodiaceae, ?Caryophyllaceae or ?Myrtaceae
Tricolpites [12]	sp.	Polygonaceae or Lamiaceae
	"sp. 2"	Polygonaceae or Lamiaceae

References

1. 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. doi:10.1016/j.orggeochem.2018.01.001. ISSN   0146-6380.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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. doi:10.3897/zookeys.635.10535. ISSN   1313-2970.
7. Ashworth, Allan C; Kuschel, Guillermo (2003-02-15). "Fossil weevils (Coleoptera: Curculionidae) from latitude 85°S Antarctica". Palaeogeography, Palaeoclimatology, Palaeoecology. 191 (2): 191–202. doi:10.1016/S0031-0182(02)00712-5. ISSN   0031-0182.
8. 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.
9. 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.
10. 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. doi:10.1098/rspb.2008.0396. PMC   2603191 . PMID   18647723.
11. 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. doi:10.1016/S0034-6667(96)00003-6. ISSN   0034-6667.
12. Askin, R.A.; Markgraf, V. (1986). "Palynomorphs from the Sirius Formation, Dominion Range, Antarctica" (PDF). Antarc. J. U.S. 21 (5): 34–35.