Synopsis top ↑
During GANOVEX VII, the geoscientific studies were focused on the following geoscientific problems: - the formation and break-up of the super-continent Gondwana, - the boundary between the East Antarctic shield and the West Antarctic mobile belts, - mountain building and crustal strengthening during the Paleozoic Ross-Orogeny, and - crustal blocking and weakening during the Mesozoic/Cenozoic Ross Sea rifting.
After first results from GANOVEX VII were published in the GANOVEX volume
"From Oates Coast to Marie Byrd Land" (Polar Issue No. 6;
Geologisches Jahrbuch, B 89), the present volume contains nine papers
whose preparation took more time because of data processing, petrological
studies, chemical analyses, etc.
The eastern shoulder of the Ross Sea (i.e., West Antarctic) rift system in Marie Byrd Land is much less known than the western rift shoulder in northern Victoria Land, marked by the highly uplifted Transantarctic Mountains. Aeromagnetic and gravity surveys were carried out on the King Edward VII Peninsula, western Marie Byrd Land, to study the crustal structure of the eastern shoulder of the Ross Sea rift system.
Apatite fission-track data from the Alexandra and Rockefeller Mountains on Edward VII Peninsula indicate that the thermal history of the eastern rift flank of northern Victoria Land was different from that of the western rift shoulder. Tectonic and isostatic control factors on the landscape evolution of the coastal mountains of northern Victoria Land and their relationship to the Ross Sea rift are discussed in one paper of this volume. Regional metamorphic rocks appear on both sides of the Ross Sea. They were affected by the Ross orogeny and are related to the formation of the Gondwana supercontinent. The type and degree of metamorphism of the Early Palaeozoic regional metamorphic rocks of the Swanson Formation in westernmost Marie Byrd Land were studied and compared with metamorphic rocks in northern Victoria Land and on South Island, New Zealand. A paper deals with the origin of the amphibolites in the Priestley Formation of the Wilson Terrane of northern Victoria Land. The composition of the volcanic parent rocks of the Bowers Terrane metamorphic rocks in northern Victoria Land and their plate tectonic setting are discussed in another paper. The gravity measurements of previous GANOVEX expeditions were continued in Victoria Land between Brimstone Peak and Coulman Island, south of Lillie Marleen Hut, and in the Oates Coast region. Two-dimensional models are used to interpret the data obtained along two profiles from the polar plateau to the coast.