Search

Palynological analyses of 12 samples from the Cape Melville Formation, which crops out on easternmost King George Island, Antarctica, provide new information on the type of vegetation that covered the South Shetland Islands during the early Miocene Melville Glaciation, c. 23–21 Ma. The assemblage recovered was mostly characterised byin situalgae such as leiospheres along with acanthomorph acritarchs, both glacial indicators. The sparsein situterrestrial palynomorph assemblage included tundra-indicative moss sporesCoptosporasp., rare podocarp conifer and various angiosperm pollen. The latter includes pollen of several species ofNothofagidites, plus rare Asteraceae, Caryophyllaceae (Colobanthus-type) andChenopodipollis.The majority of the palynomorphs recovered are interpreted as reworked, denoting glacial scouring and redeposition from various sites in the Antarctic Peninsula and the South Shetland Islands. These reworked palynomorphs are of Permian to Paleogene age. This reworked component provides insight into the potential sources of reworking, and is consistent with multiple cycles of glacial advances to the Melville Peninsula at the time of deposition. The penecontemporaneous palynomorphs recovered provide new data on the climatic regime and glacial intensification during the early Miocene on King George Island. [ABSTRACT FROM AUTHOR]

A palynological analysis was undertaken on 16 samples from seven piston cores collected along two offshore transects near Seymour and James Ross Islands. Diverse assemblages of reworked marine microplankton (including organic-walled dinoflagellate cysts, cymatiosphaerids, leiospheres, and other acritarchs) and terrestrial palynomorphs (including pollen and spores) were recovered from glacio-marine sediments of late Pleistocene age. Among the reworked taxa, four species belonging to the acritarch genus Palaeostomocystis Deflandre 1937 comprise up to 17% of all palynomorphs. Highest abundances were recorded from sites close to the coast. The potential use of Palaeostomocystis as a proxy for early ice-sheet development on the Antarctic margins is evaluated in light of earlier studies. This evaluation suggests that the high abundances of Palaeostomocystis on the Antarctic Peninsula reflect neritic-type environments (shallow waters, bay-like areas, or marginal seas) and sub-polar to polar conditions as exist in the Bering Sea, Greenland margins, and other sub- arctic to arctic areas today. [ABSTRACT FROM AUTHOR]