Late Miocene vegetation and palaeoenvironments of the Drygalski Formation, Heard Island, Indian Ocean: evidence from palynology

• Published in: Antarctic Science
• Main Authors: Truswell, EM, Quilty, PG, McMinn, A, Macphail, MK, Wheller, GE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2005
• Subjects: Earth Sciences; Geology; Palaeontology (incl. Palynology); Antarctic; Cape Lockyer; Drygalski; Heard Island; Indian; Lockyer; Southern Ocean; The Antarctic; Antarc*; Antarctic Science; Tierra del Fuego
• Online Access: https://doi.org/10.1017/S0954102005002865; http://ecite.utas.edu.au/38118

Well sorted, fine lithic sandstone within the Drygalski Formation at Cape Lockyer on the southern tip of Heard Island, preserves a diverse terrestrial palynoflora as well as marine diatoms and a few foraminifera. A combination of these elements suggests a Late Miocene age (10-5 Ma). The palaeovegetation was markedly different from that presently on the island, and appears to comprise at least two ecologically distinct communities: open heath or herbfield dominated by grasses and Asteraceae, and a more mesophytic community dominated by ferns but also including lycopods and angiosperms such as Gunnera. This may have represented a coastal flora similar to the 'fern-bush' community that exists now on Southern Ocean islands north of the Antarctic Polar Frontal Zone, and in Tierra del Fuego; however, there is no evidence of tree species in the local flora and trace amounts of tree pollen present may have blown in from other landmasses in the region. Antarctic Science Ltd.