Earth:Meyer Desert Formation

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Meyer Desert Formation
Stratigraphic range: Miocene or Pliocene
Meyer Desert Formation exposed in the Oliver Bluffs on the flanks of the Beardmore Glacier
TypeGeological formation
Unit ofSirius Group
OverliesCloudmaker Formation
Thickness185 m (607 ft)
Lithology
PrimaryDiamictite, sandstone, siltstone
OtherPeat, marlstone
Location
Coordinates [ ⚑ ] : 85°07′S 166°35′E / 85.117°S 166.583°E / -85.117; 166.583
RegionTransantarctic Mountains, Meyer Desert, Dominion Range
CountryAntarctica
ExtentOliver Bluffs, Beardmore Glacier region
Type section
Named forMeyer Desert
Named byMcKelvey 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

The area was the frontline of a major glacier in a marine-influenced Fjord, whose best analogue is Glacier Bay National Park.

The Meyer Desert Formation preserves a short-lived Pliocene interglacial tundra in a marine-influenced Fjord.[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 hollows.[1][3] This setting was similar floral-wise to the windswept cushion bush and fellfields of Patagonia and Tierra del Fuego above 800–1000 m.[3] The sequence hovewer was coastal, based on marine Diatom & Foraminifera, part of the "Beardmore Paleofjord", a major seaway extending at least 165 km through the Transantarctic Mountains from its juncture with the S Ross Sea, with the floral levels being probably a shoreline of an smaller inland sea incursion, whose best analogue is Glacier Bay National Park.[4]

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.[5] More recent data records similar floras at least until the Miocene in the Antarctic Peninsula.[6] The Pliocene age of the sediments has been constested, with two major options, one being periods were the Wilkes & Aurora subglacial basins were ice-free and sea-inundated as recent as the early Pliocene, and the other suggesting is Miocene or older, and it´s Diatoms are wind contamination.[7][8] Extant Springtails (Antarcticinella, Cryptopygus, Gomphiocephalus) that still live in the same region suggest hovewer that the ice covering of the region wasn´t until the Pliocene, as they have been isolated from each other at between 1.3 and 5.5 My.[9]

Animals

Genus Species Affinity / family Image
Antarctotrechus[10] balli Carabidae
Antarctotrechus
Chironomidae indet.[11] Indet. Midge
Curculionidae indet.[11][12] "Morphotype 1" Listroderini (aff. Listroderes)
Listroderes
"Morphotype 2" Listroderini (aff. Falklandius/Telurus)
Telurus dissimilis
Cyclorrhapha indet.[13] Indet. aff. Cochliomyia
Cochliomyia
Indet. Leg inside Ranunculus achene
Lepidoptera? indet.[11] Indet. Eggs of Moth or Butterfly
Lymnaeidae indet.[14] Indet. aff. Chilina
Chilina
Osteichthyes indet.[3] Indet. Freshwater taxon, likely a Galaxiidae[15]
Ostracod indet.[16] Indet. Putatively non-marine ostracods
Pisidium[11][14] sp. Sphaeriidae
Pisidium

Plants

Genus Species Affinity / family Image
Cushion plants indet.[3] Indet. Donatiaceae, Apiaceae, Caryophyllaceae or Asteraceae
Cyperaceae indet.[3] "Morphotype 1" Sedges
"Morphotype 2" Sedges
Hippuris[3] sp. Hippuridaceae
Hippuris
Marchantiaceae indet.[3] Indet. Liverwort
Nothofagidites[3] (Fuscospora) lachmaniae Nothofagaceae (cf. Nothofagus)
Nothofagus gunnii
Nothofagus[17] beardmorensis Nothofagaceae (aff. Nothofagus gunnii)
Poaceae indet.[3] Indet. Grass
Podocarpidites[3][18] "sp. b" Podocarpaceae (Aff. Pilgerodendron or Lepidothamnus)
Pilgerodendron
Pottiaceae indet.[3] Indet. Moss, other 4 unnamed types are found
Ranunculus[3] sp. Ranunculaceae
Ranunculus
Reniform seed indet.[3] Indet. ?Chenopodiaceae, ?Caryophyllaceae or ?Myrtaceae
Tricolpites[18] sp. Polygonaceae or Lamiaceae
"sp. 2" Polygonaceae or Lamiaceae

References

  1. ↑ 1.0 1.1 1.2 1.3 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. Bibcode: 2018OrGeo.118....4R. https://www.sciencedirect.com/science/article/pii/S014663801730219X. 
  2. ↑ 2.0 2.1 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. 
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 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. https://www.sciencedirect.com/science/article/pii/S0031018204003591. 
  4. ↑ Webb, P.-N.; Harwood, D.M.; Mabin, M.G.C.; McKelvey, B.C. (1996). "A marine and terrestrial Sirius Group succession, middle Beardmore Glacier-Queen Alexandra Range, Transantarctic Mountains, Antarctica". Marine Micropaleontology 27 (1-4): 273–297. doi:10.1016/0377-8398(95)00066-6. ISSN 0377-8398. https://doi.org/10.1016/0377-8398(95)00066-6. 
  5. ↑ Stefi Weisburd (March 1986). "A forest grows in Antarctica. (an extensive forest may have flourished about 3 million years ago)". Science News. https://www.questia.com/read/1G1-4164401. Retrieved 2012-11-02. 
  6. ↑ Bastias-Silva, Joaquin; Leppe, Marcelo; Manriquez, Leslie; Trevisan, Cristine; Fox, Bethany R. S.; Magiera, Matthias; Wilson, Gary; Tavazzani, Lorenzo et al. (2025-11-26). "Neogene plant macrofossils from West Antarctica reveal persistence of Nothofagaceae forests into the early Miocene" (in en). Communications Earth & Environment 6 (1): 965. doi:10.1038/s43247-025-02921-x. ISSN 2662-4435. https://www.nature.com/articles/s43247-025-02921-x. 
  7. ↑ Passchier, S. (2011). "Linkages between East Antarctic Ice Sheet extent and Southern Ocean temperatures based on a Pliocene high-resolution record of ice-rafted debris off Prydz Bay, East Antarctica" (in en). Paleoceanography 26 (4). doi:10.1029/2010PA002061. ISSN 1944-9186. https://onlinelibrary.wiley.com/doi/abs/10.1029/2010PA002061. 
  8. ↑ Barrett, P. J. (2013). "Resolving views on Antarctic Neogene glacial history – the Sirius debate" (in en). Earth and Environmental Science Transactions of The Royal Society of Edinburgh 104 (1): 31–53. doi:10.1017/S175569101300008X. ISSN 1755-6910. https://www.cambridge.org/core/journals/earth-and-environmental-science-transactions-of-royal-society-of-edinburgh/article/abs/resolving-views-on-antarctic-neogene-glacial-history-the-sirius-debate/29B150930B64D90C71210BE13C35F7AA. 
  9. ↑ Collins, Gemma E.; Hogg, Ian D.; Convey, Peter; Sancho, Leopoldo G.; Cowan, Don A.; Lyons, W. Berry; Adams, Byron J.; Wall, Diana H. et al. (2020-09-08). "Genetic diversity of soil invertebrates corroborates timing estimates for past collapses of the West Antarctic Ice Sheet". Proceedings of the National Academy of Sciences (Proceedings of the National Academy of Sciences) 117 (36): 22293–22302. doi:10.1073/pnas.2007925117. PMID 32839321. PMC 7486705. https://www.pnas.org/doi/full/10.1073/pnas.2007925117. 
  10. ↑ Ashworth, Allan C.; Erwin, Terry L. (2016-11-23). "Antarctotrechus balli sp. n. (Carabidae, Trechini): the first ground beetle from Antarctica" (in en). ZooKeys (635): 109–122. doi:10.3897/zookeys.635.10535. ISSN 1313-2970. PMID 27917060. Bibcode: 2016ZooK..635..109A. 
  11. ↑ 11.0 11.1 11.2 11.3 Ashworth, A.; Lewis, A.; Marchant, D.; Askin, R.; Cantrill, D.; Francis, J.; Leng, M.; Newton, A. et al. (2007-01-01). "The Neogene biota of the Transantarctic Mountains". ANDRILL Related Publications of Affiliates. https://digitalcommons.unl.edu/andrillaffiliates/5. 
  12. ↑ 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. Bibcode: 2003PPP...191..191A. https://www.sciencedirect.com/science/article/pii/S0031018202007125. 
  13. ↑ Ashworth, Allan C.; Thompson, F. Christian (2003). "A fly in the biogeographic ointment" (in en). Nature 423 (6936): 135–136. doi:10.1038/423135a. ISSN 1476-4687. https://www.nature.com/articles/423135a. 
  14. ↑ 14.0 14.1 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. https://doi.org/10.1093/mollus/69.1.89. 
  15. ↑ Burridge, Christopher P.; McDowall, Robert M.; Craw, Dave; Wilson, Mark V. H.; Waters, Jonathan M. (2012). "Marine dispersal as a pre-requisite for Gondwanan vicariance among elements of the galaxiid fish fauna" (in en). Journal of Biogeography 39 (2): 306–321. doi:10.1111/j.1365-2699.2011.02600.x. ISSN 1365-2699. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2699.2011.02600.x. 
  16. ↑ 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. PMID 18647723. Bibcode: 2008PBioS.275.2449W. 
  17. ↑ 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. Bibcode: 1996RPaPa..94...11H. https://www.sciencedirect.com/science/article/pii/S0034666796000036. 
  18. ↑ 18.0 18.1 Askin, R.A.; Markgraf, V. (1986). "Palynomorphs from the Sirius Formation, Dominion Range, Antarctica". Antarc. J. U.S. 21 (5): 34–35. https://s3.amazonaws.com/Antarctica/AJUS/AJUSvXXIn5/AJUSvXXIn5p34.pdf. 



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