Hydrothermal precipitates associated with bimodal volcanism in the Central Bransfield Strait, Antarctica

2004 ◽  
Vol 39 (3) ◽  
pp. 358-379 ◽  
Author(s):  
Sven Petersen ◽  
Peter M. Herzig ◽  
Ulrich Schwarz-Schampera ◽  
Mark D. Hannington ◽  
Ian R. Jonasson
2020 ◽  
Vol 20 (2) ◽  
pp. 1-6 ◽  
Author(s):  
E. E. Khimchenko ◽  
D. I. Frey ◽  
E. G. Morozov

2016 ◽  
Vol 3 ◽  
Author(s):  
James B. Bell ◽  
Clare Woulds ◽  
Lee E. Brown ◽  
Christopher J. Sweeting ◽  
William D. K. Reid ◽  
...  

2006 ◽  
Vol 69 (4) ◽  
pp. 373-399 ◽  
Author(s):  
C. Lacasse ◽  
H. Sigurdsson ◽  
S. N. Carey ◽  
H. Jóhannesson ◽  
L. E. Thomas ◽  
...  

Oceanology ◽  
2014 ◽  
Vol 54 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Al. A. Schreider ◽  
A. A. Schreider ◽  
E. I. Evsenko
Keyword(s):  

2021 ◽  
Author(s):  
Eugene Morozov ◽  
Dmitry Frey ◽  
Elizaveta Khimchenko

<p>Observations of tidal internal waves in the Bransfield Strait, Antarctica, are analyzed. The measurements were carried out for 14 days on a moored station equipped with five autonomous temperature and pressure sensors. The mooring was deployed on the slope of Nelson Island (South Shetland Islands archipelago) over a depth of 70 m at point 62°21ꞌ S, 58°49ꞌ W. Analysis is based on the fluctuations of isotherms.  Vertical displacements of temperature revealed that strong internal vertical oscillations up to 30–40 m are caused by the diurnal internal tide. Spectral analysis of vertical displacements of the 0.9°C isotherm showed a clear peak at a period of 24 h. It is known that the tides in the Bransfield Strait are mostly mixed diurnal and semidiurnal, but during the Antarctic summer, diurnal tide component may intensify. The velocity ellipses of the barotropic tidal currents were estimated using the global tidal model TPXO9.0. It was found that tidal ellipses rotate clockwise with a period of 24 h and anticlockwise with a period of 12 h. The waves are forced due to the interaction of the barotropic tide with the bottom topography. Diurnal internal tides do not develop at latitudes higher than 30º over flat bottom. The research was supported by RFBR grant 20-08-00246.</p>


2017 ◽  
Vol 6 (1) ◽  
pp. 155
Author(s):  
Yao Honoré Koffi ◽  
Sagbrou Chérubin Djro ◽  
Urbain Wenmenga

The Djarkadougou gold prospect is located on the Birimian greenstone belt of the Houndé exploration permit held by the company Orezone Inc. The permit is at 275 km far from the capital Ouagadougou south- western Burkina Faso, West Africa. This area is based on sheared and metamorphosed greenschist facies rocks. Metamorphism locally reaches to the amphibolite facies around intrusions. There are two major lithological units whose interface is marked by a NW-SE trending shear corridor: an unit of andesite-basaltic rocks of andesitic breccias in the East and volcaniclastic and sedimentary unit composed flows, tuffs and felsic to mafic breccia, interbedded volcano-sedimentary rocks. All this together is intruded by plutonic rocks, and various felsic to mafic dykes. These rocks have undergone ductile to brittle heterogeneous deformations and hydrothermal alteration sericite ±carbonate ±quartz±sulphide within deformation corridors. The rocks of the East and West domains affected by three phases of brittle-ductile deformation (D1, D2, and D3) and the meteoric alteration is systematic in superficial facies of Djarakadougou core drilling.Geochemical analysis shows a tholeiitic to calc-alkaline volcanic serie characteristic a bimodal volcanism. The spectra of normalized REE chondrites are generally flat and constant reminding those of N-MORB basalt. The chemical compositions of andesite and basalt are deferred on several discrimination diagrams especially Th / Yb - Nb / Yb and 2 Nb - Zr / 4 - Y show that andesites and basalts of the prospect are issued in geotectonic setting of volcanism preponderant arc.


Author(s):  
Eduardo M. Ruiz Barlett ◽  
Gabriela V. Tosonotto ◽  
Alberto R. Piola ◽  
Marta E. Sierra ◽  
Mauricio M. Mata

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