Shafer Peak Formation

The Shafer Peak Formation is a geological formation in Antarctica, dating to roughly between 185 million years ago and covering the Pliensbachian stages of the Jurassic Period in the Mesozoic Era. Plant remains are know from the formation.The Shafer Peak Formation is interpreted as a succession of fluvially reworked, silicic volcanic ashes, and presumably is a regional equivalent of the Hanson Formation in the central Transantarctic Mountains.[1]

Shafer Peak Formation Stratigraphic range: 185 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Unit of	Section Peak Formation
Thickness	50 metres (160 ft)
Lithology
Primary	Silicic tuffitic silt- and fine-grained sandstones
Other	Climbing-ripple lamination, horizontal lamination, and accumulations of clay-gall rip-up clasts
Location
Region	North Victoria Land
Country	Antarctica

Fossils

Flora

Plant remains occur at the base of the lacustrine beds directly underlying the initial pillow lavas at the top of the sedimentary profile.[2]

Genus	Species	Location	Stratigraphic position	Material	Notes
Isoetites[3]	I. crociformis	Shafer Peak		Specimens.[3]	A member of the family Isoetaceae.
Equisetites[3]	E. muensteri	Shafer Peak		Specimens.[3]	A member of the family Equisetaceae.
Clathropteris[3]	C. meniscoides	Shafer Peak		Specimens.[3]	A member of the family Dipteridaceae.
Matonidium[3]	M. goeppertii	Shafer Peak		Specimens.[3]	A member of the family Matoniaceae.
Coniopteris[3]	C. murrayana C. hymenophylloides	Shafer Peak		Specimens.[3]	A member of the family Dicksoniaceae.
Spiropteris[3]	Spiropteris sp.	Shafer Peak		Specimens.[3]	Incertae sedis.
Otozamites[3]	O. linearis O. sanctae-crucis	Shafer Peak		Specimens.[3]	A member of the family Bennettitales.
Zamites[3]	Z. gigas	Shafer Peak		Specimens.[3]	A member of the family Bennettitales.
Cycadolepis[3]	Cycadolepis sp.	Shafer Peak		Specimens.[3]	A member of the family Bennettitales.
Schizolepis[3]	Schizolepis sp.	Shafer Peak		Specimens.[3]	A member of the family Voltziales.
Allocladus[3]	cf. Allocladus sp	Shafer Peak		Specimens.[3]	A member of the family Coniferales.
Elatocladus[3]	cf. Elatocladus sp.	Shafer Peak		Specimens.[3]	A member of the family Coniferales.
Pagiophyllum[3]	cf. Pagiophyllum sp	Shafer Peak		Specimens.[3]	A member of the family Coniferales.

Insecta

The basal layers of the overlying lacustrine series have yielded highly fragmented and thus unidentifiable arthropod cuticles.[2]

Genus	Species	Location	Stratigraphic position	Material	Notes
Coleoptera[2]	Unnamed	Mount Carson		Elytron.[2]	Non compared.
Blattidae[2]	Unnamed	SW Gair Mesa		Complete specimen.[2]	Similar to the genus Periplaneta

See also

• Hanson Formation
• Mawson Formation

References

1. Schöner, R., Viereck-Goette, L., Schneider, J., Bomfleur, B., Cooper, A. K., & Raymond, C. R. (2007, August). Triassic-Jurassic sediments and multiple volcanic events in north Victoria Land, Antarctica: a revised stratigraphic model. In Antarctica: A Keystone in a Changing World–Online Proceedings of the 10th ISAES, edited by AK Cooper and CR Raymond et al., USGS Open-File Report (Vol. 1047).
2. Bomfleur, B., Schneider, J. W., Schöner, R., Viereck-Götte, L., & Kerp, H. (2011). Fossil sites in the continental Victoria and Ferrar groups (Triassic-Jurassic) of north Victoria Land, Antarctica. Polarforschung, 80(2), 88-99.
3. Bomfleur, B., Pott, C., & Kerp, H. (2011). Plant assemblages from the Shafer Peak Formation (Lower Jurassic), north Victoria Land, Transantarctic Mountains. Antarctic Science, 23(2), 188-208.