scholarly journals Geology of the northern margin of the Trans-Hudson Orogen (Foxe Fold Belt), central Baffin Island, Nunavut

2001 ◽  
Author(s):  
D Corrigan ◽  
D J Scott ◽  
M R St-Onge
Keyword(s):  
Baffin Island ◽  
Fold Belt ◽  
Northern Margin

Wandel Sea Basin, eastern North Greenland

1998 ◽  
pp. 55-62 ◽  
Author(s):  
Lars Stemmerik ◽  
Finn Dalhoff ◽  
Birgitte D. Larsen ◽  
Jens Lyck ◽  
Anders Mathiesen ◽  
...  
Keyword(s):  
Barents Sea ◽  
Fault System ◽  
Hydrocarbon Potential ◽  
Fold Belt ◽  
Related Field ◽  
Northern Margin ◽  
Late Mesozoic ◽  
Early Tertiary ◽  
Late Palaeozoic ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemmerik, L., Dalhoff, F., Larsen, B. D., Lyck, J., Mathiesen, A., & Nilsson, I. (1998). Wandel Sea Basin, eastern North Greenland. Geology of Greenland Survey Bulletin, 180, 55-62. https://doi.org/10.34194/ggub.v180.5086 _______________ The Wandel Sea Basin in eastern North Greenland is the northernmost of a series of fault-bounded Late Palaeozoic – Early Tertiary basins exposed along the eastern and northern margin of Greenland (Fig. 1). The basin and the surrounding shelf areas are located in a geologically complex region at the junction between the N–S trending Caledonian fold belt in East Greenland and the E–W trending Ellesmerian fold belt in North Greenland, and along the zone of later, Tertiary, continental break-up. The Wandel Sea Basin started to develop during the Carboniferous as a result of extension and rifting between Greenland and Norway, and Greenland and Spitsbergen (Håkansson & Stemmerik 1989), and was an area of accumulation during the Early Carboniferous – Early Tertiary period. Two main epochs of basin evolution have been recognised during previous studies of the basin fill: an early (late Palaeozoic – early Triassic) epoch characterised by a fairly simple system of grabens and half-grabens, and a late (Mesozoic) epoch dominated by strike-slip movements (Håkansson & Stemmerik 1989). The Mesozoic epoch only influenced the northern part of the basin, north of the Trolle Land fault zone (Fig. 1). Thus the northern and southern parts of the basin have very different structural and depositional histories, and accordingly different thermal histories and hydrocarbon potential. This paper summarises the results of a project supported by Energy Research Program (EFP-94), the purpose of which was to model the Wandel Sea Basin with special emphasis on hydrocarbon potential and late uplift history, and to provide biostratigraphic and sedimentological data that could improve correlation with Svalbard and the Barents Sea. It is mainly based on material collected during field work in Holm Land and Amdrup Land in the south-eastern part of the Wandel Sea Basin during 1993–1995 with additional data from eastern Peary Land (Stemmerik et al. 1996). Petroleum related field studies have concentrated on detailed sedimentological and biostratigraphic studies of the Carboniferous–Permian Sortebakker, Kap Jungersen, Foldedal and Kim Fjelde Formations in Holm Land and Amdrup Land (Fig. 2; Døssing 1995; Stemmerik 1996; Stemmerik et al. 1997). They were supplemented by a structural study of northern Amdrup Land in order to improve the understanding of the eastward extension of the Trolle Land fault system and possibly predict its influence in the shelf areas (Stemmerik et al. 1995a; Larsen 1996). Furthermore, samples for thermal maturity analysis and biostratigraphy were collected from the Mesozoic of Kap Rigsdagen and the Tertiary of Prinsesse Thyra Ø (Fig. 1).

scholarly journals ARCABOUÇO TECTÔNICO E ESTRATIGRÁFICO DA FAIXA RIACHO DO PONTAL, DIVISA PERNAMBUCO-PIAUI-BAHIA

2013 ◽  
Author(s):  
Fabrício de Andrade Caxito ◽  
Alexandre Uhlein
Keyword(s):  
Plate Tectonics ◽  
Central Zone ◽  
Fold Belt ◽  
Northern Margin ◽  
External Zone ◽  
Metasedimentary Rocks ◽  
Late Neoproterozoic ◽  
Brasiliano Orogeny ◽  
Augen Gneiss ◽  
Ocean Ridge

A faixa brasiliana Riacho do Pontal bordeja a margem norte do Cráton do São Francisco e pode ser subdividida em três domíniosou zonas tectônicas de características geológicas contrastantes, de norte para sul: zonas Interna, Central, e Externa. A Zona Interna édominada por rochas metavulcanosedimentares intrudidas por rochas plutônicas relacionadas à Orogênese Cariris Velhos (augen-gnaissesda Suíte Afeição, ~1.0-0.9 Ga). A Zona Central é caracterizada pelo Complexo Monte Orebe, composto por metabasaltos de geoquímicasimilar aos basaltos de cadeia oceânica e rochas metassedimentares de ambiente marinho profundo. A Zona Externa é caracterizada pelosistema de nappes Casa Nova, composto por duas unidades: A Formação Barra Bonita na base, que representa uma sequência plataformaldesenvolvida na borda norte do paleocontinente São Francisco; e a Formação Mandacaru no topo, que representa uma sequência marinhaprofunda turbidítica, provavelmente sin-orogênica. Essas rochas foram afetadas por deformação compressiva (D1-D2-D3) com odesenvolvimento do sistema de nappes vergentes para sul, durante o Neoproterozoico (~630-575 Ma), seguida por deformaçãotranscorrente (D4) nos estágios tardios da Orogênese Brasiliana. Toda a faixa é intrudida por múltiplas gerações de plútons graníticos esieníticos sin a pós-colisionais, de idade neoproterozóica a cambriana (~630-530 Ma). A Faixa Riacho do Pontal representa um ciclo deplacas tectônicas completo no Neoproterozoico tardio, envolvendo a colisão do cráton do São Francisco a sul com os blocos litosféricos daProvíncia Borborema a norte.Palavras chave: Orogênese Brasiliana, Faixa Riacho do Pontal, Cráton do São Francisco ABSTRACTTECTONIC AND STRATIGRAPHIC FRAMEWORK OF THE RIACHO DO PONTAL FOLD BELT, PERNAMBUCO-PIAUI-BAHIA BORDER.The Riacho do Pontal Fold Belt borders the northern margin of the São Francisco Craton and can be subdivided into three tectonic domainsor zones of distinct geology, from north to south: the Internal, Central, and External zones. The Internal Zone is composed bymetavulcanosedimentary rocks intruded by plutonic rocks related to the Cariris Velhos Orogeny (Afeição Suite augen-gneiss, ~1.0-0.9 Ga);rocks of this age are absent in the other zones. The Central Zone is characterized by the Monte Orebe Complex, composed by metabasaltswhose geochemistry is similar to mid-ocean ridge basalts and deep marine metasedimentary rocks. The External Zone is characterized bythe Casa Nova nappe system, composed by two units: (a) the Barra Bonita Formation at the base, representing a platformal sequencedeveloped at the northern São Francisco Craton margin; and (b) the Mandacaru Formation at the top, which represents a syn-orogenicdeep marine unit. These rocks were affected by compressive deformation (D1-D2-D3) with the development of a south-verging nappesystem, during the Neoproterozoic (~630-575 Ma), followed by strike-slip deformation (D4) at the late stages of the Brasiliano Orogeny.The whole fold belt is intruded by multiple generations of syn- to post-collisional granitic and syenitic plutons, of Neoproterozoic toCambrian age (~630-530 Ma). The Riacho do Pontal Fold Belt represents a complete plate tectonics cycle at the late Neoproterozoic,involving the collision of the São Francisco Craton to the South with the crustal blocks of the Borborema Province towards North.Keywords: Brasiliano Orogeny, Riacho do Pontal Fold Belt, São Francisco Craton

Geology of the Foxe Fold Belt, Baffin Island, District of Franklin

1975 ◽  
Author(s):  
W C Morgan ◽  
J Bourne ◽  
R K Herd ◽  
J W Pickett ◽  
C R Tippett
Keyword(s):  
Baffin Island ◽  
Fold Belt

Metamorphic evolution of the Petersen Bay assemblage, Ellesmere Island: What can we learn about Pearya - Laurentia accretion?

2020 ◽  
Author(s):  
Karolina Kośmińska ◽  
Jane Gilotti ◽  
William McClelland ◽  
Matthew Coble
Keyword(s):  
Middle Devonian ◽  
Bulk Composition ◽  
Arctic Region ◽  
Ellesmere Island ◽  
The Arctic ◽  
Garnet Growth ◽  
Fold Belt ◽  
Weighted Mean ◽  
Northern Margin ◽  
Garnet Core

<p>The accretion of the Pearya terrane to the northern margin of Laurentia plays an important role in the paleogeographic reconstructions for the Arctic region. Earlier workers proposed a timing of its juxtaposition spanning from Late Silurian (Trettin, 1998) to Late Ordovician (Klaper 1992). In this study, we focus on the pressure-temperature-time (P-T-t) evolution of the Petersen Bay assemblage. This subduction related unit crops out between the crystalline basement of Pearya and volcano-sedimentary sequence of Clements Markham fold belt. The highest grade rocks, garnet-kyanite-bearing schist (sample 17-66) and garnet-kyanite-staurolite garbenschiefer (sample 17-64) were selected for P-T studies and in-situ monazite U-Pb dating by sensitive high resolution ion microprobe.</p><p>Thermodynamic modelling of sample 17-66 gives a P-T condition of 7.8-8.1 kbar and 590-610°C for garnet core formation, whereas a pseudosection calculated for the effective bulk composition indicates garnet rim growth at 8-9 kbar and 650-660°C. The QuiG Raman barometry coupled with Ti-in-biotite thermometry yield conditions of 6.5-7.5 kbar and 540-600°C for the garnet growth. The combination of QuiG barometry and Ti-in-biotite thermometry indicate garnet growth at 7.5-8 kbar and 500-550°C for the garbenschiefer sample.</p><p>Monazite shows distinctive zonation and 2, up to 3, domains were recognized based on textures and X-ray microprobe maps. For the sample 17-66, Monazite-I forms inclusions within garnet rims or cores of bigger matrix grains. It defines a weighted mean <sup>206</sup>Pb/<sup>238</sup>U age of 397±2 Ma (n=18, MSWD=1.6). Monazite-II occurs in the matrix and gives an age of 385±2 Ma (n=19, MSWD=1.5). Monazite-I from sample 17-64 yields a weighted mean <sup>206</sup>Pb/<sup>238</sup>U age of 394±2 Ma (n=11, MSWD=0.6). Monazite-II defines the age of 388±2 Ma (n=7, MSWD=0.8). Monazite-III was distinct only in garbenschiefer. It yields a younger age of 374±6 Ma (n=6, MSWD=3.1).</p><p>The P–T data coupled with monazite dating suggest a Middle Devonian metamorphism of the Petersen Bay assemblage under amphibolite facies conditions. These new results suggest that the juxtaposition of the Pearya terrane, Petersen Bay assemblage and the Clemens Markham fold belt is Middle Devonian or younger, i.e. much younger than previously thought.</p><p>References</p><p>Klaper E.M. 1992. The Paleozoic tectonic evolution of the northern edge of North America: A structural study of Northern Ellesmere Island, Canadian Arctic Archipelago Tectonics, 11, 854–870.</p><p>Trettin H.P. 1998. Pre-Carboniferous geology of the northern part of the Arctic Islands: Northern Heiberg Fold Belt, Clements Markham Fold Belt, and Pearya; northern Axel Heiberg and Ellesmere islands GSC Bulletin, 425, 401 p.</p>

A Regional Stratigraphic Isochron (ca. 8000 14C yr B.P.) from Final Deglaciation of Hudson Strait

1996 ◽  
Vol 46 (2) ◽  
pp. 89-98 ◽  
Author(s):  
Michael W. Kerwin
Keyword(s):  
Sediment Cores ◽  
Laurentide Ice Sheet ◽  
Time Interval ◽  
Hudson Bay ◽  
Baffin Island ◽  
Clay Layer ◽  
X Ray ◽  
Northern Margin ◽  
Group A ◽  
Glaciomarine Sediments

Sedimentologic, rock-magnetic, and X-ray fluorescence data from two marine sediment cores in Hudson Strait suggest that a red, hematite-rich clay layer was deposited throughout the strait during the final collapse of the Laurentide Ice Sheet in the vicinity of northern Hudson Bay and western Hudson Strait. This layer, which can be recognized by its reddish-pink color (10YR6/2 to 5YR4/2) and relatively high-hematite proportions (low magnetic susceptibility and magnetite-to-hematite ratio), is dated from 8000 to 7900 14C yr B.P. at both ends of the strait. The Dubawnt Group, a Proterozoic bedrock unit in northern Hudson Bay, is the most likely source of this stratigraphic isochron. In eastern Hudson strait, the recognition of this red unit and other distal glaciomarine sediments from 8400 to 7900 14C yr B.P. indicates that little sediment from the nearby Labrador Dome reached eastern Hudson Strait during this 500-yr interval. This time interval immediately postdates the Noble Inlet advance, a northward flow of Labrador ice across eastern Hudson Strait onto southern Baffin Island from ca. 8900 to 8400 14C yr B.P. One explanation for the lack of Labrador sediments is that the northern margin of the Labrador dome was cold-based for up to 500 yr following the Noble Inlet advance.

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