Some centric diatoms (Bacillariophyta) from Neogene deposits of the Fisher Massif (Prince Charles Mountains, East Antarctica)

2011 ◽  
Vol 45 ◽  
pp. 32-49
Author(s):  
R. M. Gogorev ◽  
Z. V. Pushina
Keyword(s):  
Marine Sediments ◽  
East Antarctica ◽  
Benthic Diatoms ◽  
Detailed Data ◽  
Planktonic Algae ◽  
Centric Diatoms ◽  
Planktonic Diatom ◽  
Oceanic Species ◽  
Diatom Complexes

The richest diatom complexes have revealed due to the study of glacial-marine sediments sampled in the Fisher Massif (Prince Charles Mountains, East Antarctica) during 52nd and 53rd Russian Antarctic Expeditions (Polar Marine Geol. Survey Expedition) in 2006/07 and 2007/08. Three diatom complexes are distinguished according to different palaeoecological conditions: the planktonic one is located in the basis of the outcrop, while mixed planktonic-benthic and benthic ones being located above. The planktonic diatom complexes are dominated by two oceanic species Actinocyclus ingens (up to 8%) and Denticulopsis simonseni (up to 80%). There are 15 planktonic algae, e. g. Eucampia аntarctica, Fragilariopsis spp., Rhizosolenia spp., Rouxia antarctica, Podosira antarctica sp. nov., Stellarima microtrias; and also unknown and non-described benthic diatoms Achnanthes sp., Cocconeis spp., Rhabdonema (s. l.) spp. and Synedra (s. l.) spp. Detailed data on morphology and taxonomy of 10 centric diatoms are presented, including 3 newly described species.

Сentric diatoms (Biddulphiales, Hemiaulales, Rhizosoleniales, Chaetocerotales, Bacillariophyta) from Neogene deposits of the Fisher Massif (Prince Charles Mountains, East Antarctica)

2012 ◽  
Vol 46 ◽  
pp. 36-45
Author(s):  
R. M. Gogorev ◽  
Z. M. Pushina
Keyword(s):  
New Species ◽  
Marine Sediments ◽  
East Antarctica ◽  
Detailed Data ◽  
Centric Diatoms ◽  
Two New Species

Detailed data on morphology and taxonomy of 11 species of centric diatoms from the Neogene glacial-marine sediments of the Fisher Massif (Prince Charles Mountains, East Antarctica) are presented. Two new species Dicladia antarctica Gogorev et Pushina sp. nov. and Trigonium antarcticum Gogorev et Pushina sp. nov. are described.

Phytoplankton of the La Trobe River, Victoria

1985 ◽  
Vol 36 (1) ◽  
pp. 115 ◽  
Author(s):  
BC Chessman
Keyword(s):  
Chlorophyll A ◽  
Marked Reduction ◽  
Benthic Diatoms ◽  
Monthly Basis ◽  
Centric Diatoms ◽  
Cell Densities

Phytoplankton was sampled on a monthly basis for 1 year at five stations on the La Trobe River in Gippsland, Victoria. In the upper, mostly forested, reaches of the river, chlorophyll a concentrations and cell densities were uniformly very low, and the dominant algae were detached benthic diatoms and flagellated species. In the plains section of the river, downstream of an impoundment (Lake Narracan), spring and autumn blooms occurred, with a marked reduction in abundance in midsummer and midwinter. The lowland planktonic flora was dominated by centric diatoms, particularly Melosira distans in autumn and Skeletonema potamos in spring.

scholarly journals Basal conditions beneath enhanced-flow tributaries of Slessor Glacier, East Antarctica

2006 ◽  
Vol 52 (179) ◽  
pp. 481-490 ◽  
Author(s):  
D.M. Rippin ◽  
J.L. Bamber ◽  
M.J. Siegert ◽  
D.G. Vaughan ◽  
H.F.J. Corr
Keyword(s):  
Sea Level ◽  
Marine Sediments ◽  
East Antarctica ◽  
Flow Rates ◽  
The Past ◽  
Radio Echo Sounding ◽  
Slow Moving ◽  
Bed Roughness ◽  
Rough Beds ◽  
Interesting Area

AbstractRadio-echo sounding data are used to investigate bed roughness beneath the three enhanced-flow tributaries of Slessor Glacier, East Antarctica. Slow-moving inter-tributary areas are found to have rough beds, while the bed of the northernmost tributary is relatively smooth. A reconstruction of potential subglacial drainage routing indicates that water would be routed down this tributary, and investigations of basal topography following isostatic recovery reveal that the bed would have been below sea level in preglacial times, so marine sediments may have accumulated here. Together, these factors are further support for the dominance of basal motion in this tributary, reported elsewhere. Conversely, although the other two Slessor tributaries may have water routed beneath them, they would not have been below sea level before the growth of the ice sheet, so cannot be underlain by marine sediments. They are also found to be rough, and, within the range of uncertainties, it is likely that basal motion does not play a major role in the flow of these tributaries. Perhaps the most interesting area, however, is a deep trough where flow rates are currently low but the bed is as smooth as the northern Slessor trough. It is proposed that, although ice deformation currently dominates in this trough, basal motion may have occurred in the past, when the ice was thicker.

Bulk Sediment and Diatom Silica Carbon Isotope Composition from Coastal Marine Sediments off East Antarctica

Silicon ◽  
2012 ◽  
Vol 5 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Sonja Berg ◽  
Melanie J. Leng ◽  
Christopher P. Kendrick ◽  
Holger Cremer ◽  
Bernd Wagner
Keyword(s):  
Carbon Isotope ◽  
Marine Sediments ◽  
Isotope Composition ◽  
Carbon Isotope Composition ◽  
East Antarctica ◽  
Bulk Sediment ◽  
Coastal Marine Sediments ◽  
Coastal Marine ◽  
Diatom Silica

The catabolic fission of the aromatic ring of phenylalanine by marine planktonic algae

1971 ◽  
Vol 49 (2) ◽  
pp. 259-261 ◽  
Author(s):  
J. R. Vose ◽  
J. Y. Cheng ◽  
N. J. Antia ◽  
G. H. N. Towers
Keyword(s):  
Aromatic Ring ◽  
Marine Species ◽  
Planktonic Algae ◽  
Catabolic Activity ◽  
Centric Diatoms ◽  
Pennate Diatoms

Twenty-two unicellular marine species belonging to seven algal divisions were tested for their ability to cleave the aromatic ring of phenylalanine. Nine species showed production of 14CO2 after incubation with 14C-ring labeled DL-phenylalanine. This catabolic activity was randomly distributed among the algal classes, although it appeared to be particularly common in pennate diatoms and absent in centric diatoms.

Suspected meteorite fragments in marine sediments from East Antarctica

2018 ◽  
Vol 30 (5) ◽  
pp. 307-321
Author(s):  
Naresh C. Pant ◽  
Francisco J. Jimenez-Espejo ◽  
Cary P. Cook ◽  
Paromita Biswas ◽  
Robert Mckay ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Mafic Rock ◽  
East Antarctica ◽  
Time Interval ◽  
Ocean Drilling Program ◽  
Rock Fragments ◽  
Integrated Ocean Drilling Program ◽  
Wilkes Land ◽  
Oxygen Isotopic ◽  
Sediment Layers

AbstractUnusual mafic rock fragments deposited in Plio-Pleistocene-aged marine sediments were recorded at Integrated Ocean Drilling Program (IODP) Site U1359, in Wilkes Land, East Antarctica. These fragments were identified from sediment layers deposited between c. 3 and 1.2 Ma, indicating a sustained supply during this time interval. Clinopyroxenes in these basalts are Al–Ti diopside–hedenbergite, uncommon in terrestrial magmatic rocks. A single strong peak in the Raman spectra of a phosphate-bearing mineral at 963 cm-1 supports the presence of merrillite. Although not conclusive, petrological traits and oxygen isotopic compositions also suggest that the fragments may be extra-terrestrial fragments affected by shock metamorphism. Nevertheless, it is concluded that the basaltic fragments incorporated in marine sediments at Site U1359 represent ice-rafted material supplied to the continental rise of East Antarctica, probably from the bedrocks near the proximal Ninnis Glacier. Further studies on Plio-Pleistocene sediments near Site U1359 are required to characterize the unusual mafic rocks described.

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