Oligocene to Holocene erosion and glacial history in Marie Byrd Land, West Antarctica, inferred from exhumation of the Dorrel Rock intrusive complex and from volcano morphologies

2006 ◽  
Vol 118 (7-8) ◽  
pp. 991-1005 ◽  
Author(s):  
S. Rocchi ◽  
W. E. LeMasurier ◽  
G. Di Vincenzo
Keyword(s):  
Intrusive Complex ◽  
Glacial History ◽  
West Antarctica

Englacial stratigraphy in Ellsworth Subglacial Highlands, West Antarctica

2021 ◽  
Author(s):  
Felipe Napoleoni ◽  
Neil Ross ◽  
Michael J. Bentley ◽  
Stewart S.R. Jamieson ◽  
Andrew M. Smith ◽  
...  
Keyword(s):  
Internal Structure ◽  
Ice Sheet ◽  
Glacial History ◽  
West Antarctica ◽  
Large Area ◽  
Ice Dynamics ◽  
Ice Flow ◽  
Surface Mass ◽  
West Antarctic ◽  
Ice Stream

<p>Airborne ice-penetrating radar surveys around the Ellsworth Subglacial Highlands (ESH) have mapped and dated englacial ice sheet layers, hereafter referred to as ‘Internal Reflection Horizons’ (IRHs). The geometry and internal structure of IRHs can reveal the cumulative effects of surface mass balance, strain, basal melt and ice dynamics, to improve understanding of the glacial history of West Antarctic Ice Sheet (WAIS). Despite the airborne-surveyed IRHs however, international efforts to develop a continental-wide scale coverage of IRHs (i.e. AntArchitecture), are limited by a lack of data in the critical regions between the upper reach of Pine Island Glacier (PIG), Rutford Ice Stream (RIS) and Institute Ice Stream (IIS). This region is important because any significant collapse of WAIS or reorganisation of ice flow would likely be felt in the ESH because it hosts deep subglacial troughs (Ellsworth Trough and CECs Trough), that represent a potential connection between the Weddell and Amundsen Seas. Using an extensive ground-based ice radar dataset acquired by Centro de Estudios Científicos (CECs) we bridge this regional gap by mapping IRHs across the Amundsen-Weddell divide of the WAIS. This work links airborne-derived IRH datasets across PIG and IIS, to develop an extensive layer characterisation across a large area of West Antarctica. We present the regional internal structure of the ice sheet, gridded paleo ice surfaces, and identify areas with complex IRH structures, and evaluate the possible glaciological processes responsible. We then compare our results with modelled outputs of ice sheet geometry and outline our current understanding of the past ice flow behaviour of the ESH, and the implications for WAIS glacial history. We consider our results in the context of the characterisation of ‘old-ice’ in WAIS and in relation to the upcoming plans for accessing subglacial Lake CECs in order to determine its history.</p>

Miocene to Pleistocene glacial history of West Antarctica inferred from Nunatak geomorphology and cosmogenic-nuclide measurements on bedrock surfaces

2020 ◽  
Vol 320 (8) ◽  
pp. 637-676
Author(s):  
Perry Spector ◽  
John Stone ◽  
Greg Balco ◽  
Trevor Hillebrand ◽  
Mika Thompson ◽  
...  
Keyword(s):  
Glacial History ◽  
West Antarctica ◽  
Cosmogenic Nuclide ◽  
History Of

Carbon and nitrogen zooplankton isoscapes in West Antarctica reflect oceanographic transitions

2018 ◽  
Vol 593 ◽  
pp. 29-45 ◽  
Author(s):  
EK Brault ◽  
PL Koch ◽  
KW McMahon ◽  
KH Broach ◽  
AP Rosenfield ◽  
...  
Keyword(s):  
West Antarctica ◽  
Carbon And Nitrogen

Central West Antarctica aeromagnetic data; a web site for distribution of data and maps (paper edition)

1999 ◽  
Author(s):  
R.E. Sweeney ◽  
C.A. Finn ◽  
D.D. Blankenship ◽  
R.E. Bell ◽  
John C. Behrendt
Keyword(s):  
Web Site ◽  
Aeromagnetic Data ◽  
West Antarctica ◽  
Paper Edition

Ultramafic-alkaline-carbonatite complexes as a result of two-stage melting of mantle plume: evidence from the mid-paleoproterozoic Tiksheozero intrusion, Northern Karelia, Russia

2019 ◽  
Vol 486 (4) ◽  
pp. 460-465
Author(s):  
E. V. Sharkov ◽  
A. V. Chistyakov ◽  
M. M. Bogina ◽  
O. A. Bogatikov ◽  
V. V. Shchiptsov ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Mantle Plume ◽  
Large Igneous Province ◽  
Intrusive Complex ◽  
Incongruent Melting ◽  
Isotopic Data ◽  
Two Stage ◽  
Similar Composition ◽  
Igneous Province ◽  
Alkaline Magmas

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids  that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland

1999 ◽  
pp. 103-112
Author(s):  
Feiko Kalsbeek ◽  
Lilian Skjernaa
Keyword(s):  
Intrusive Complex ◽  
The South ◽  
Original Series ◽  
Early Proterozoic ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Southern Border ◽  
Area North ◽  
Igneous Layering

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kalsbeek, F., & Skjernaa, L. (1999). The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 103-112. https://doi.org/10.34194/ggub.v181.5118 _______________ The 2800 Ma Atâ intrusive complex (elsewhere referred to as ‘Atâ granite’ or ‘Atâ tonalite’), which occupies an area of c. 400 km2 in the area north-east of Disko Bugt, was emplaced into grey migmatitic gneisses and supracrustal rocks. At its southern border the Atâ complex is cut by younger granites. The complex is divided by a belt of supracrustal rocks into a western, mainly tonalitic part, and an eastern part consisting mainly of granodiorite and trondhjemite. The ‘eastern complex’ is a classical pluton. It is little deformed in its central part, displaying well-preserved igneous layering and local orbicular textures. Near its intrusive contact with the overlying supracrustal rocks the rocks become foliated, with foliation parallel to the contact. The Atâ intrusive complex has escaped much of the later Archaean and early Proterozoic deformation and metamorphism that characterises the gneisses to the north and to the south; it belongs to the best-preserved Archaean tonalite-trondhjemite-granodiorite intrusions in Greenland.

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