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Sulphide and oxide ore mineralization at Reptile Ridge, Adelaide Island, West Antarctica

100%

Birkenmajer K. , Doktor M. , Piestrzyński A.

tom Vol. 47, nr 2-3

135-153

Metalliferous sulphide and oxide mineralization was studied at Reptile Ridge, Adelaide Island, West Antarctica. It occurs in metavolcanics and metaquanzites of the Antarctic Peninsula Volcanic Group (APVG: Upper Jurassic - Lower Cretaceous) and, to a lesser degree, in adamellite-granodiorite pluton of the Andean Intnisive Suite (AIS: probably Cretaceous). The mineralization zone had developed along a NNE-SSW-striking fault which displaces the volcanics (APVG) and the pluton (AIS). Among sulphides, pyrite, pyrrhotite, sphene and chalcopyrite are the most common. The oxides are represented mainly by magnetite, haematite, haemoilmenite and rutile. Two phases of pneumatolytic-hydrothermal mineralization were recognized in the metaquartzites (APVG): (1) the first phase produced Fe-Ti mineral association in form of veins and fills of intergranular spaces; (2) the second phase produced Fe-Cu sulphide mineralization mainly as fills of intergranular spaces.

Geochronology of selected andesitic lavas from the King George Bay area (SE King George Island)

88%

Pańczyk M. , Nawrocki J.

tom Vol. 55, No. 4

323-334

Volcanic rocks from the Lions Rump area, which are the basement for a sequence of glaciomarine sediments of the Polonez Cove Formation, and lava flows from the Turret Point–Three Sisters Point area were sampled for thermogeochronological and palaeomagnetic investigations. Generally, andesitic lavas from King George Bay area consist mainly of clinopyroxene (Ti-augite) orthopyroxene (hyperstene) and plagioclase phenocrysts. The groundmass comprises mostly plagioclase laths, clinopyroxene, titanomagnetite and rare orthopyroxene crystals. However, the modal content, size, shape and distribution of phenocrysts are variable and specific for each sample. The Ar-Ar plateaus ages calculated for lavas from the Lions Rump area are very homogenous and point to middle Eocene age (Lutetian, ~44.5 Ma). The similar and consistent ages for volcanic basement for that area excluded the thesis about separate tectonic evolution of the Warszawa and Kraków blocks at least since the middle Eocene. The lavas from Turret Point and Three Sister Point are younger and were emplaced during the late Eocene (Bartonian/Priabonian: 37.3 š0.4 Ma and Priabonian: 35.35 š0.15 Ma, respectively). The results of isotopic investigations are consistent with magnetic polarities of the rocks indicating that the samples from the Lions Rump area are coeval with the lower part of the C20 polarity chron whereas the sample from Turret Point can be correlated with the upper part of the C17 polarity chron

2-D seismic models of the lithosphere in the area of the Bransfield Strait, West Antarctica

75%

Grad M. , Guterch A. , Janik T. , Środa P. , Grad M. , Guterch A. , Janik T. , Środa P.

nr 2

Report on the Polish geological investigations in the Antarctic Peninsula sector, 1987—1988

75%

Birkenmajer K. , Birkenmajer K.

nr 4

Polish Geodynamic Expeditions - seismic structure of West Antarctica

63%

Guterch A. , Grad M. , Janik T. , Środa P. , Guterch A. , Grad M. , Janik T. , Środa P.

Report on the Polish geological investigations in West Antarctica, 1990/91

63%

Birkenmajer K. , Birkenmajer K.

nr 3

Geochronologia skał wulkanicznych centralnej i południowej części Wyspy Króla Jerzego (Szetlandy Południowe, Zachodnia Antarktyka)

63%

Pańczyk M.

Przegląd Geologiczny

2013

tom Vol. 61, nr 2

117--119

New isotopic and paleomagnetic studies of volcanic rocks from the central and southern part of the King George Island and Penguin Island were carried out. The combination of three dating methods: single grain U-Pb dating of separated zircons, whole-rock 40Ar-39Ar dating and magnetostratigraphy allow distinguishing five magmatic activity phases: the oldest, late Cretaceous (Campanian), early to middle Eocene (about 53–43 Ma), late Eocene (about 37–35 Ma), late Oligocene (about 28–25 Ma) and, the youngest, late Pliocene to Holocene.