Geology of South Georgia and the South Sandwich Islands information
The geology of South Georgia and the South Sandwich Islands is part of the largely submerged Scotia Ridge. The island of South Georgia is unusual among oceanic islands for having pre-Cretaceous sedimentary rocks underlying much of the island and a significant portion of felsic igneous rocks. Two-thirds of the island consists of intensely folded flysch, capped with Aptian age fossils, tuff and greywacke in the Cumberland Bay Series. The series includes slate, phyllite, conglomerate, siltstone and sandstone. In the west are basalt flows, pillowed spilite, prehnite and trachyandesite, as well as shale with radiolarite fossils.[1]
Uranium-lead dating of zircon and muscovite grains from the southern Andes and South Georgia (gathered from the peraluminous Darwin granite suite and undersea Tobifera Formation rhyolite) indicates that the rocks formed during the middle Jurassic. The grains were likely remnant from 1.5 billion years ago.
The fragmentation of the Gondwana supercontinent is preserved in an ophiolite in the Rocas Verdes marginal basin—part of the Larsen Harbour complex on South Georgia. As the continent fragmented, oceanic crust formed in the Weddell Sea in the Middle Jurassic. The ridge's Beagle granite suite has complicated uranium-lead data. Feldspar phenocrysts formed in cracks within the Beagle granite pluton, likely related to the tectonism affecting the high-grade metamorphic rocks of the Cordillera Darwin in Tierra del Fuego.[2]
^Frakes, Lawrence A. (1966). "GEOLOGIC SETTING OF SOUTH GEORGIA ISLAND | GSA Bulletin". Geological Society of America Bulletin. 77 (12): 1463. doi:10.1130/0016-7606(1966)77[1463:GSOSGI]2.0.CO;2. Retrieved 6 November 2018.
^Mukasa, Samuel B.; Dalziel, Ian W.D. (1996). "Southernmost Andes and South Georgia Island, North Scotia Ridge: Zircon U-Pb and muscovite 40Ar39Ar age constraints on tectonic evolution of Southwestern Gondwanaland". Journal of South American Earth Sciences. 9 (5–6): 349–365. doi:10.1016/S0895-9811(96)00019-3.
and 24 Related for: Geology of South Georgia and the South Sandwich Islands information
inhospitable collection ofislands, consisting ofSouthGeorgiaand a chain of smaller islands known as theSouthSandwichIslands. SouthGeorgia is 165 kilometres...
are administered as part ofthe British Overseas Territory ofSouthGeorgiaandtheSouthSandwichIslands. The chain lies in the sub-Antarctic region, about...
The 2021 SouthSandwichIslands earthquakes were a pair of powerful earthquakes, followed by many strong aftershocks which struck along theSouth Sandwich...
located southeast of South Georgia in theSouth Atlantic Ocean. It is the northernmost oftheSouthSandwichIslandsand consists of one major stratovolcano...
Vindication Island is a small uninhabited islandofthe Candlemas Islands in theSouthSandwichIslands. It is one of about a dozen islands that make up the South...
of SouthGeorgiaandtheSouthSandwichIslands. Southern Thule is the southernmost island group in theSouthSandwichIslands, an archipelago in the Southern...
Candlemas Island is a small uninhabited islandofthe Candlemas Islands in theSouthSandwichIslands. It is one of about a dozen islands that make up the South...
exceptions of SouthGeorgia on its northeastern edge andthe southern tip ofSouth America. Together with theSandwich Plate, the Scotia Plate joins the southernmost...
from Hamberg Lakes to the coast close southof Horse Head in Cumberland East Bay, SouthGeorgia. It was first surveyed by the Swedish Antarctic Expedition...
Visokoi Island is an uninhabited volcanic island in the Traversay Islands subgroup oftheSouthSandwichIslands, which are located southeast ofSouth Georgia...
The Clerke Rocks are a group of small rocky islands some 35 miles (56 km) southeast ofSouthGeorgia that extend 5 miles (8.0 km) from east to west. The...
List of volcanoes in Montserrat List of volcanoes in SouthSandwichIslands Emeleus, C.H.; Bell, B.R. (2005). The Palaeogene volcanic districts of Scotland...
by geology (e.g. Bermuda, the Australian Indian Ocean Territories) or by common geopolitical convention (e.g. Ascension Island, theSouthSandwich Islands)...
Leskov Island is an island in theSouthSandwichIslands named after Russian sailor Arcady Leskov. It is a semicircular 190 metres (620 ft) high eroded...