In the austral summer 2017/18, in the framework of the 33rd ItaliAntatyide Expedition, a three person team performed geological and geological-glacial field mapping in the Convoy Range (Victoria Land, Antarctica), at the scale 1/250’000. Activity was heli-supported, starting from the Italian base in Terra Nova Bay (Mario Zucchelli Station), and interested the Convoy Range and the Franklin Island quadrangles of the USGS 1/250’000 Reconnaissance Series. The activity had two principal targets: – to fill the gap existing between the area covered by the GIGAMAP programme (Pertusati et al., 2016) to the north and the geological maps by GNS Science (New Zealand) to the south (Gunn & Warren, 1962; Pocknall et al., 1994; Cox et al., 2012), by mapping the area comprised between 76° and 76°30’S and between 159° and 163° E; – to collect new data (stratigraphic, structural, sedimentological and petrographic data) to better characterize the lithotectonic units cropping out in the investigated area. In more detail, in Antarctica the activity included geological and geological-glacial field mapping, photogeological analyses, structural observations and rock sampling. In this area, the dolerite and basalt of the the Ferrar Group and the sandstone of the Beacon Supergroup (i.e. the rocks of the Gondwanian sequence) are prevalent. Granites and granodiorites of the Granite Harbour Igneous Complex constitute the crystalline basement underlying the Gondwanian sequence; such basement occurs only in the sector that is close to the Ross Sea coast. Minor enclaves of Wilson Terrane gneiss are hosted in the Granite Harbour granitoid. During the mapping activity, we collected rock samples (more than 120) for subsequent laboratory analyses and also gathered attitude measurements of bedding, faults and fractures. For the glacial geological mapping, we collected rock samples to perform Surface Exposure Dating, by analyses on selected cosmogenic isotope. On return from Antarctica, the activity comprised digitisation of the new cartographic data and their integration in the digital dataset of the Geomap Action Group; elaboration of structural data; microstructural analyses and minero-petrographic analyses of rocks and glacial deposits. Cox, S.C., Turnbull, I.M., Townsend, D.B., & Smith Lyttle, M. (2012): Geology of southern Victoria Land. GNS Science 22, 1:250000 Map. Gunn, B.M., Warren, G. (1962): Geology of Victoria Land between Mawson and Mullock Glaciers, Antarctica. New Zealand Geological Survey Bulletin, 71, 156 p. Pertusati, P.C., Ricci, C.A. & Tessensohn, F. (2016): German-Italian Geological Antarctic Map Programme. Terra Antartica Reports, 15, 1-15. Pocknall, D.T., Chinn, T.J., Skyes, R. & Skinner, D.N.B. (1994): Geology of the Convoy Range Area, southern Victoria Land, Antarctica. GNS Science Geological Map 11, 36 p. + 1 map
Filling the gap between the GIGAMAP and the GNS maps in Victoria Land, Antarctica: geological mapping in the Convoy Range
Capponi, G.;Casale, S.;Montomoli, C.;Iaccarino, S.;Musumeci, G.;Salvatore, M. C.;
2018-01-01
Abstract
In the austral summer 2017/18, in the framework of the 33rd ItaliAntatyide Expedition, a three person team performed geological and geological-glacial field mapping in the Convoy Range (Victoria Land, Antarctica), at the scale 1/250’000. Activity was heli-supported, starting from the Italian base in Terra Nova Bay (Mario Zucchelli Station), and interested the Convoy Range and the Franklin Island quadrangles of the USGS 1/250’000 Reconnaissance Series. The activity had two principal targets: – to fill the gap existing between the area covered by the GIGAMAP programme (Pertusati et al., 2016) to the north and the geological maps by GNS Science (New Zealand) to the south (Gunn & Warren, 1962; Pocknall et al., 1994; Cox et al., 2012), by mapping the area comprised between 76° and 76°30’S and between 159° and 163° E; – to collect new data (stratigraphic, structural, sedimentological and petrographic data) to better characterize the lithotectonic units cropping out in the investigated area. In more detail, in Antarctica the activity included geological and geological-glacial field mapping, photogeological analyses, structural observations and rock sampling. In this area, the dolerite and basalt of the the Ferrar Group and the sandstone of the Beacon Supergroup (i.e. the rocks of the Gondwanian sequence) are prevalent. Granites and granodiorites of the Granite Harbour Igneous Complex constitute the crystalline basement underlying the Gondwanian sequence; such basement occurs only in the sector that is close to the Ross Sea coast. Minor enclaves of Wilson Terrane gneiss are hosted in the Granite Harbour granitoid. During the mapping activity, we collected rock samples (more than 120) for subsequent laboratory analyses and also gathered attitude measurements of bedding, faults and fractures. For the glacial geological mapping, we collected rock samples to perform Surface Exposure Dating, by analyses on selected cosmogenic isotope. On return from Antarctica, the activity comprised digitisation of the new cartographic data and their integration in the digital dataset of the Geomap Action Group; elaboration of structural data; microstructural analyses and minero-petrographic analyses of rocks and glacial deposits. Cox, S.C., Turnbull, I.M., Townsend, D.B., & Smith Lyttle, M. (2012): Geology of southern Victoria Land. GNS Science 22, 1:250000 Map. Gunn, B.M., Warren, G. (1962): Geology of Victoria Land between Mawson and Mullock Glaciers, Antarctica. New Zealand Geological Survey Bulletin, 71, 156 p. Pertusati, P.C., Ricci, C.A. & Tessensohn, F. (2016): German-Italian Geological Antarctic Map Programme. Terra Antartica Reports, 15, 1-15. Pocknall, D.T., Chinn, T.J., Skyes, R. & Skinner, D.N.B. (1994): Geology of the Convoy Range Area, southern Victoria Land, Antarctica. GNS Science Geological Map 11, 36 p. + 1 mapI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
