Clay mineral composition in shallow water sediment samples near the Antarctic Peninsula and in deep-sea core samples from the pacific and the Indian-Antarctic Basins

1980 ◽  
Vol 36 (1) ◽  
pp. 23-29
Author(s):  
Saburo Aoki ◽  
Kaoru Oinuma
Keyword(s):  
Shallow Water ◽  
Mineral Composition ◽  
Clay Mineral ◽  
Antarctic Peninsula ◽  
Deep Sea ◽  
Sediment Samples ◽  
The Pacific ◽  
The Antarctic ◽  
Shallow Water Sediment ◽  
Clay Mineral Composition

Chapter 3.1b Antarctic Peninsula and South Shetland Islands: petrology

2021 ◽  
pp. M55-2018-68 ◽  
Author(s):  
Philip T. Leat ◽  
Teal R. Riley
Keyword(s):  
Antarctic Peninsula ◽  
Continental Margin ◽  
Volcanic Rocks ◽  
Oceanic Lithosphere ◽  
Contact Metamorphism ◽  
South Shetland Islands ◽  
Calc Alkaline ◽  
The Pacific ◽  
High K ◽  
The Antarctic

AbstractThe Antarctic Peninsula contains a record of continental-margin volcanism extending from Jurassic to Recent times. Subduction of the Pacific oceanic lithosphere beneath the continental margin developed after Late Jurassic volcanism in Alexander Island that was related to extension of the continental margin. Mesozoic ocean-floor basalts emplaced within the Alexander Island accretionary complex have compositions derived from Pacific mantle. The Antarctic Peninsula volcanic arc was active from about Early Cretaceous times until the Early Miocene. It was affected by hydrothermal alteration, and by regional and contact metamorphism generally of zeolite to prehnite–pumpellyite facies. Distinct geochemical groups recognized within the volcanic rocks suggest varied magma generation processes related to changes in subduction dynamics. The four groups are: calc-alkaline, high-Mg andesitic, adakitic and high-Zr, the last two being described in this arc for the first time. The dominant calc-alkaline group ranges from primitive mafic magmas to rhyolite, and from low- to high-K in composition, and was generated from a mantle wedge with variable depletion. The high-Mg and adakitic rocks indicate periods of melting of the subducting slab and variable equilibration of the melts with mantle. The high-Zr group is interpreted as peralkaline and may have been related to extension of the arc.

scholarly journals V. Preliminary report to Professor Wyville Thomson, F. R. S., Director of the Civilian Scientific Staff, on crustacea observed during the cruise of H. M. S. 'Challenger' in the Southern Sea

1876 ◽  
Vol 24 (164-170) ◽  
pp. 585-592
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Preliminary Report ◽  
The South ◽  
Short Account ◽  
Prince Edward Islands ◽  
Scientific Staff ◽  
Large Island ◽  
The Antarctic

In the following paper it is intended to give a short account of the Crustacea found at the bottom as well as on the surface of the sea during the antarctic cruise of H. M. S. ‘Challenger.’ Our expedition, as is probably well-known to most readers, left the Cape on Decem­ber 17, proceeded towards the Prince-Edward Islands, and landed on one of them. Between these islands and the Crozets, on which landing was impossible, we had several successful deep-sea dredgings. From the Crozets we sailed to Kerguelen, where we stayed nearly a month, and where a great deal of shallow-water dredging was done. Proceeding from this large island to the south, we penetrated beyond the antarctic circle, and had four successful deep-sea dredgings near the ice-barrier. On our way to Australia we were able to trawl five times. The surface animals were generally collected by the towing-net at every station by lowering the net to a depth of 50-100 fathoms, where, as experience has shown us, nearly the same quantity of animals are found during the day which at night are to be got from the very surface. In fine nights, when the ship»was gliding very slowly through the water, the net was of course always put out, and its contents were carefully preserved; but during our antarctic cruise such nights were rare, so that in most cases we had to lower the net in the daytime, during the manipulations of dredging and sounding.

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