Palaeoproterozoic and Archaean gneiss complexes in northern Greenland: Palaeoproterozoic terrane assembly in the High Arctic

Nutman, Allen P.; Dawes, P.R; Kalsbeek, Feiko; Hamilton, M. A.

doi:10.1016/j.precamres.2007.09.006

Cited by 66 publications

(74 citation statements)

References 72 publications

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“…To account for the trend in gravity residuals along the fjord, the southern, grounded end of the profile must be underlain by denser material than the northern, seaward end. This requires either that the northern end be made of less dense material -either the Silurian carbonate reefs or a thick pile of loose sediment, or that denser rock exists at the grounding line, such as the crystalline orthogneiss that has been identified in the nearby Victoria fjord (Henriksen et al, 2009;Nutman et al, 2008). It is likely that a combination of these effects contributes to the observed trend.…”

Section: Geology Of Petermann Fjordmentioning

confidence: 99%

Bathymetry in Petermann fjord from Operation IceBridge aerogravity

Tinto

Bell

Cochran

et al. 2015

Earth and Planetary Science Letters

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Petermann Glacier is a major glacier in northern Greenland, maintaining one of the few remaining floating ice tongues in Greenland. Monitoring programs, such as NASA's Operation IceBridge have surveyed Petermann Glacier over several decades and have found it to be stable in terms of mass balance, velocity and grounding-line position. The future vulnerability of this large glacier to changing ocean temperatures and climate depends on the ocean-ice interactions beneath its floating tongue. These cannot currently be predicted due to a lack of knowledge of the bathymetry underneath the ice tongue.Here we use aerogravity data from Operation IceBridge, together with airborne radar and laser data and shipborne bathymetry-soundings to model the bathymetry beneath the Petermann ice tongue. We find a basement-cored inner sill at 540-610 m depth that results in a water cavity with minimum thickness of 400 m about 25 km from the grounding line. The sill is coincident with the location of the melt rate minimum. Seaward of the sill the fjord is strongly asymmetric. The deepest point occurs on the eastern side of the fjord at 1150 m, 600 m deeper than on the western side. This asymmetry is due to a sedimentary deposit on the western side of the fjord. A 350-410 m-deep outer sill, also mapped by marine surveys, marks the seaward end of the fjord. This outer sill is aligned with the proposed Last Glacial Maximum (LGM) grounding-line position for Petermann Glacier. The inner sill likely provided a stable pinning point for the grounding line in the past, punctuating the retreat of Petermann Glacier since the LGM.

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Section: Geology Of Petermann Fjordmentioning

confidence: 99%

Bathymetry in Petermann fjord from Operation IceBridge aerogravity

Tinto

Bell

Cochran

et al. 2015

Earth and Planetary Science Letters

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“…Age information from zircons in orthogneiss is complex, but suggests an Eoarchean age at ca. 3400 Ma for the protolith with later Archean and Neoprtoterozoic-Paleozoic overprint (Hansen et al, 1987;Nutman et al, 2008a).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…11; Dawes, 2004;Nutman et al, 2008a;St-Onge et al, 2009). The Inglefield Belt is subdivided into two terranes by the < 1800 Ma, E-trending, moderately to steeply N-dipping sinistral Sunrise Pynt Shear Zone, the Central Terrane and the Southern Terrane ( Fig.…”

Section: Inglefield Beltmentioning

confidence: 99%

“…The Inglefield Belt is subdivided into two terranes by the < 1800 Ma, E-trending, moderately to steeply N-dipping sinistral Sunrise Pynt Shear Zone, the Central Terrane and the Southern Terrane ( Fig. 11; Nutman et al, 2008a). In the Southern Terrane in Prudhoe Land, Paleoproterozoic rocks overly and intrude Neoarchean rocks of the Rae Craton .…”

Section: Inglefield Beltmentioning

confidence: 99%

“…They are intruded by the precursors of orthogneiss at ca. 1985 Ma (Dawes, 2006;Nutman et al, 2008a). Archean…”

Section: Inglefield Beltmentioning

confidence: 99%

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Metallogeny of Greenland

Kolb

Keiding

Steenfelt

et al. 2016

Ore Geology Reviews

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Geochemistry of the Cambrian Sirius Passet Lagerstätte, Northern Greenland

Boudec

Ineson

Rosing

et al. 2014

Geochem. Geophys. Geosyst.

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The lower Cambrian Sirius Passet Lagerst€ atte (518 Ma) consists of mudstones about 8 m thick located in the Franklinian Basin of North Greenland. We analyzed major and trace elements plus the S, C, Cu, Fe, Zn, and Mo isotope compositions. Factor analysis allowed the lithology of the mudstone to be broken down into variable proportions of two inputs, a dry felsic component and a hydrous mafic component (smectite or chlorite). Zircons U-Pb ages indicate multiple sources, the local Proterozoic basement of Northern Greenland (1250-2400 Ma) and Pan-African felsic magmas (620-650 Ma) from across the Iapetus ocean. Diagenesis involved the reduction of Fe, S, and Mo from seawater and pyritization. The Sirius Passet Lagerst€ atte formed in oxygen-starved muds inhibiting degradation of organic matter underneath a wellventilated water column. The chemistry of the samples, their very fine grain size, their apparent lack of graded bedding, and the age of zircons suggest that the Lagerst€ atte may represent wind-blown dust deposited on the continental slope.

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Palaeoproterozoic and Archaean gneiss complexes in northern Greenland: Palaeoproterozoic terrane assembly in the High Arctic

Cited by 66 publications

References 72 publications

Bathymetry in Petermann fjord from Operation IceBridge aerogravity

Bathymetry in Petermann fjord from Operation IceBridge aerogravity

Metallogeny of Greenland

Geochemistry of the Cambrian Sirius Passet Lagerstätte, Northern Greenland

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