Articles de revues : « Hopedale »

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Bingham-Koslowski, N., M. A. Miller, T. McCartney et J. S. Carey. « Revised biostratigraphic and thermal alteration interpretations for the Paleozoic of the Hopedale Basin, offshore Labrador, Canada ». Bulletin of Canadian Petroleum Geology 67, n^o 3 (1 septembre 2019) : 185–214. http://dx.doi.org/10.35767/gscpgbull.67.3.185.

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Abstract Paleozoic rocks occur in seven wells in the Hopedale Basin, offshore Labrador (Hopedale E-33, South Hopedale L-39, Tyrk P-100, Gudrid H-55, Roberval K-92, Indian Harbour M-52, and Freydis B-87), where they represent erosional remnants primarily associated with Cretaceous syn-rift half grabens. Previous palynological studies have reported a range of ages for the Paleozoic in these wells, including Ordovician, Devonian, Carboniferous, and undifferentiated Paleozoic. Palynological analyses in the present study confirm that recovery is limited, primarily due to the predominance of lithologies that hinder palynomorph preservation, specifically dolostones. Palynomorphs (predominantly acritarchs and chitinozoans) have been analyzed from new and archived samples from the seven wells and have, for the first time, produced consistent age determinations for the Paleozoic strata in all wells: palynomorph assemblages considered in place indicate a Middle to Late Ordovician age. Thermal maturity was determined from Ordovician acritarchs and leiospheres observed in the Gudrid H-55, Roberval K-92, Indian Harbour M-52, and Freydis B-87 wells, with thermal alteration indices (TAI) ranging from approximately 5+ to 6+ (dry gas). Carboniferous miospores are present from Paleozoic strata in the southern Hopedale Basin wells, where their TAI values range from 3+ to 4. These miospores are interpreted as contaminants introduced into the samples via cavings or as drilling mud contamination. The data presented here provides new biostratigraphic constraints for the Paleozoic of the Hopedale Basin (Middle to Late Ordovician), facilitates the correlation of the Paleozoic intervals in these wells, and enables the consideration of Labrador margin Lower Paleozoic strata in regional studies as well as in paleogeographic and paleoenvironmental reconstructions.

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Finn, Gregory C. « Rb–Sr geochronology of the Archaean Maggo gneiss from the Hopedale block, Nain Province, Labrador ». Canadian Journal of Earth Sciences 26, n^o 12 (1 décembre 1989) : 2512–22. http://dx.doi.org/10.1139/e89-214.

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The Maggo gneiss, a typical grey gneiss from the Hopedale block of coastal Labrador (southern Nain Province), preserves structures of two major Archaean tectonothermal events, the Hopedalian and the younger Fiordian. Rb–Sr whole-rock analyses of four suites representing the Hopedalian event (3140 ± 95 Ma (1σ), 3125 ± 43 Ma, 3028 ± 199 Ma, and 3025 ± 163 Ma) fall within the early middle Archaean and represent a period of cratonization of the Hopedale block.Two suites with a younger Fiordian structural fabric (2899 ± 116 Ma and 2804 ± 100 Ma) fall within the late middle Archaean and are interpreted as dating a period of reworking that locally reset the Rb–Sr isotopic systematics of the Maggo gneiss. Fiordian ages were also determined from four suites (2927 ± 50 Ma, 2884 ± 86 Ma, 2854 ± 83 Ma, and 2764 ± 89 Ma) that do not display the Fiordian structural fabric, indicating that chemical and mechanical components of the Fiordian event did not occur simultaneously. Age determinations of the Fiordian do not date specific geologic events but seemingly reflect varying degrees of protracted isotopic homogenization during chemical and mineralogical reequilibration.One suite of analyses yields an age of 3305 ± 75 Ma and is interpreted as dating a pre-Hopedalian event. This older age supports field evidence as to the existence of old crust in the Hopedale block, typical also of rocks of the North Atlantic Craton.

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Wasteneys, Hardolph A., Richard J. Wardle et Thomas E. Krogh. « Extrapolation of tectonic boundaries across the Labrador shelf : U–Pb geochronology of well samples ». Canadian Journal of Earth Sciences 33, n^o 9 (1 septembre 1996) : 1308–24. http://dx.doi.org/10.1139/e96-099.

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Near Saglek Fiord, a northerly trending boundary between the early Archean Saglek block and the middle Archean Hopedale block extends between drill sites which, respectively, sampled Uivak amphibolite gneiss with U–Pb zircon intercept ages of 3742 ± 12 and 2752 ± 42 Ma, and migmatitic Lister gneiss with concordant ages of [Formula: see text] for restite and [Formula: see text], for leucosome. Titanite ages of ca. 2508 Ma are common to both rocks. A nearby metapsammitic gneiss has detrital zircon and monazite ages of 2681 ± 5, 2700 ± 4, ca. 2730, and 2750 ± 2 Ma representing high-grade metamorphism related to the Hopedale–Saglek collision and metamorphic monazite of ca. 2560 Ma age representing metamorphism of the sediment during reactivation of the Saglek–Hopedale suture. Two hundred kilometres southeast, a gneissic granite records a protolith age of 3170 Ma and Late Proterozoic Pb loss. Near the Nain–Makkovik boundary, 1269 ± 4 Ma zircons indicate a significant extension of the Nain Platonic Suite. South of the Makkovik boundary, a foliated granite yielded an upper intercept age defining intrusion at 1895 ± 8 Ma and concordant 1872 ± 5 Ma titanite ages that date subsequent metamorphism. Discordant U–Pb ages from an alkali-feldspar granite also constrain crystallization to ca. 1890 Ma and together with the gneiss represent the previously defined Iggiuk event in the Kaipokok domain. Wells near the southerly end of the transect record 1801 ± 5, 1813 ± 3, and 1806 ± 8 Ma ages, respectively, that are typical of the synorogenic granitoid suite representing the Cape Harrison domain of southern Makkovik Province.

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Fishman, Robert, et Edward K. Spann. « Hopedale : From Commune to Company Town, 1840-1920. » American Historical Review 99, n^o 3 (juin 1994) : 976. http://dx.doi.org/10.2307/2167925.

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Hall, Christopher J., Walter J. Henry et Craig R. Hyder. « Hopedale Branch : A Vessel of Opportunity Success Story ». International Oil Spill Conference Proceedings 2011, n^o 1 (mars 2011) : abs407. http://dx.doi.org/10.7901/2169-3358-2011-1-407.

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Greenwood, Richard E., Edward K. Spann et Laurence F. Gross. « Hopedale : From Commune to Company Town, 1840-1920 ». New England Quarterly 67, n^o 1 (mars 1994) : 170. http://dx.doi.org/10.2307/366473.

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Nøhr-Hansen, Henrik, Graham L. Williams et Robert A. Fensome. « Biostratigraphic correlation of the western and eastern margins of the Labrador–Baffin Seaway and implications for the regional geology ». GEUS Bulletin 37 (28 décembre 2016) : 1–74. http://dx.doi.org/10.34194/geusb.v37.4356.

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New analyses of the palynological assemblages in 13 offshore wells on the Canadian margin and six on the West Greenland Margin, in conjunction with onshore data, have led to a new biostratigraphic framework for the Cretaceous–Cenozoic strata of the Labrador Sea – Davis Strait – Baffin Bay (Labrador–Baffin Seaway) region and the first broad biostratigraphic correlation of the Canadian and Greenland margins. This framework is based on 167 last occurrences and 18 local/regional peak/common-occurrence events for dinocysts, miospores, fungal spores and Azolla. Detailed biostratigraphic evidence has confirmed the following hiatuses: pre-Aptian in the Hopedale Basin; pre-Albian in the Saglek Basin; Albian–Turonian in some wells of the Hopedale Basin; Turonian–Santonian/Campanian in some areas; pre-Campanian and late Campanian – Thanetian on the Greenland Margin; late Maastrichtian and Danian in some wells of the Hopedale Basin and in the Saglek Basin; Selandian in part of the Hopedale Basin, in all the Saglek Basin wells and in two wells on the West Greenland Margin; late Ypresian and/or Lutetian on both sides; Oligocene to middle Miocene of considerable variability on both margins, with all of the Oligocene and the lower Miocene missing in all the West Greenland Margin wells; and middle to late Miocene on the western side. On the Canadian margin, the hiatuses can be partially matched with the five previously recognised regional unconformities; on the Greenland margin, however, the relationship to the five unconformities is more tenuous. Palynomorph assemblages show that most Aptian to Albian sediments were deposited in generally non-marine to marginal marine settings, interrupted by a short-lived shallow marine episode in the Aptian. A marine transgression started in the Cenomanian–Turonian and led to the most open-marine, oceanic conditions in the Campanian–Lutetian; shallowing probably started in the late Lutetian and continued into the Rupelian, when inner neritic and marginal marine palaeoenvironments predominated. Throughout the rest of the Cenozoic, inner neritic palaeoenvironments alternated with marginal marine conditions on the margins of the Labrador–Baffin Seaway. These observations broadly reflect the tectonic evolution of the seaway, with rift conditions prevailing from Aptian to Danian times, followed by drift through much of the Paleocene and Eocene, and post-drift from Oligocene to the present. Dinocysts indicate that climatic conditions in the Labrador–Baffin Seaway region were relatively temperate in the Cretaceous, but varied dramatically through the Cenozoic. The Danian was a time of increasingly warmer climate, a thermal maximum being reached around the Paleocene–Eocene boundary reflecting the global thermal event at this time. Warm to hot conditions prevailed throughout the Ypresian, but the climate began to cool in the Lutetian, a trend that accelerated through the Priabonian and Rupelian. Throughout the Neogene, temperatures generally declined, culminating in the Quaternary.

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Scott, David J. « U–Pb geochronology of the Nain craton on the eastern margin of the Torngat Orogen, Labrador ». Canadian Journal of Earth Sciences 32, n^o 11 (1 novembre 1995) : 1859–69. http://dx.doi.org/10.1139/e95-143.

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New U–Pb geochronological results provide insight into the geological evolution of the northernmost Nain craton. A tonalitic orthogneiss, retrogressed from granulite to amphibolite facies, is interpreted to have crystallized at 2832 ± 3 Ma; zircon overgrowths, dated at 2769 ± 5 Ma, are interpreted as metamorphic in origin, whereas metamorphic monazite crystallized at 2692 ± 2 Ma. The crystallization age of this sample suggests it may be correlative with similar rocks of the Kanairiktok Plutonic Suite of the Hopedale block, whereas the age of the zircon overgrowths is synchronous with metamorphism in the Saglek block and may indicate a link at this time. A foliated tonalité crystallized at 2802 ± 2 Ma; titanite in this sample records deformation at 1745 ± 4 Ma; the emplacement age suggests a link with Hopedale block, whereas the titanite growth is clearly related to Torngat orogeny. Two foliated granites crystallized at 2587 ± 3 and 2564 ± 2 Ma, respectively, synchronous with late magmatic events recognized in the southern Nain craton. An Avayalik mafic dyke was emplaced at [Formula: see text] Ma, and subsequently metamorphosed at [Formula: see text] Ma. An intraboudin granitic pegmatite crystallized at 1780 ± 2 Ma, and titanite in a diorite formed at 1735 ± 3 Ma, recording the effects of deformation in the Komaktorvik shear zone during Torngat orogeny.

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Connelly, J. N., et B. Ryan. « Late Archean evolution of the Nain Province, Nain, Labrador : imprint of a collision ». Canadian Journal of Earth Sciences 33, n^o 9 (1 septembre 1996) : 1325–42. http://dx.doi.org/10.1139/e96-100.

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Archean gneisses of the Nain Province in the Nain area, Labrador, comprise narrow septa between intrusions of the Mesoproterozoic Nain Plutonic Suite. This region occupies a critical position between the northern (Saglek) and southern (Hopedale) blocks of the Nain Province, which experienced distinct thermotectonic histories until the late Archean. Field and geochronological evidence are indicative of a strong late Archean thermotectonic overprint that is absent from most of the remainder of the Nain Province. Archean gneisses were intruded by granites and mafic dykes at 2578 ± 3 and [Formula: see text], respectively, and subsequently subjected to amphibolite- to granulite-facies regional metamorphism and ductile shearing at ca. 2550 Ma; granite veins and dykes related to the Nain Plutonic Suite were emplaced at ca. 1310 Ma. The Archean events are interpreted to represent the juxtapositioning and final docking of Saglek and Hopedale blocks to form a single, stable cratonic mass during the late Archean. Corroborative evidence indicates that the collisional boundary zone could extend at least 200 km to the north and 150 km to the south of Nain. This late Archean junction may have subsequently been exploited by several Paleoproterozoic granitic intrusions and some members of the Mesoproterozoic Nain Plutonic Suite.

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Rollmann. « Literacy and Awakening : The Awakening of 1804/1805 in Hopedale, Labrador ». Journal of Moravian History 20, n^o 2 (2020) : 125. http://dx.doi.org/10.5325/jmorahist.20.2.0125.

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James, D. T., S. Kamo et T. Krogh. « Evolution of 3.1 and 3.0 Ga volcanic belts and a new thermotectonic model for the Hopedale Block, North Atlantic craton (Canada) ». Canadian Journal of Earth Sciences 39, n^o 5 (1 mai 2002) : 687–710. http://dx.doi.org/10.1139/e01-092.

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A new model for evolution of the Archean Hopedale Block, based on mapping and supporting UPb geochronological and geochemical studies, is highlighted by (i) ca. 3.25 Ga emplacement of igneous precursors of Maggo Gneiss; (ii) &gt3.1 Ga, high-grade Hopedalian metamorphism and attendant deformation; (iii) emplacement of the Hopedale mafic dykes; (iv) 3.1 Ga deposition of Hunt River volcanic rocks; (v) ca. 3.0 Ga deposition of Florence Lake volcanic rocks; (vi) 2.882.96 Ga, greenschist- to amphibolite-facies Fiordian metamorphism and formation of penetrative, northeast-striking Fiordian structures; and (vii) emplacement of a suite of 2.892.83 Ga tonalite to granite intrusions, which partially overlap and locally postdate Fiordian metamorphism and deformation. The Hunt River and Florence Lake volcanic sequences are different in age but similar in most other respects. The former consists mainly of amphibolite-facies mafic metavolcanic rocks and lesser amounts of komatiite flows and metasedimentary and 3105 ± 3 Ma felsic volcanic rocks. The Florence Lake volcanic belt consists mainly of greenschist- to amphibolite-facies mafic metavolcanic rocks, lesser amounts of felsic metavolcanic rocks, dated at 2979 ± 1 and 2990 ± 2 Ma, komatiite flows, and rare metasedimentary rocks. The similarity of rock types, field relationships between different rock types, such as the common association of ultramafic and felsic metavolcanic rocks, and the chemistry of volcanic rocks in both belts suggest a common tectonic setting for each belt. A model involving episodic volcanism, separated by 100 Ma, in ensialic basins is consistent with the dominance of tholeiitic basalt and an abundance of pre-volcanic basement.

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Richling, Barnett. « Stuck Up On a Rock : Resettlement and Community Development in Hopedale, Labrador ». Human Organization 44, n^o 4 (décembre 1985) : 348–53. http://dx.doi.org/10.17730/humo.44.4.t553t2685u183063.

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Cadman, Andrew C., John Tarney, R. Graham Park et Ingo F. Ermanovics. « Retrogression, geochemical alteration and deformation in Proterozoic mafic dykes, Hopedale block, Labrador ». Lithos 29, n^o 1-2 (décembre 1992) : 141–56. http://dx.doi.org/10.1016/0024-4937(92)90038-z.

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Maliat, Afreen, Siddhanth Kotian, Samaneh Shirinnezhad et Davoud Ghahremanlou. « Enhancing Sustainability in Hopedale, Newfoundland and Labrador, Through Hybrid Microgrid System Design ». Power Engineering and Engineering Thermophysics 3, n^o 1 (31 mars 2024) : 58–76. http://dx.doi.org/10.56578/peet030105.

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Cadman, Andrew C., R. Graham Park, John Tarney et Henry C. Halls. « Significance of anisotropy of magnetic susceptibility fabrics in Proterozoic mafic dykes, Hopedale Block, Labrador ». Tectonophysics 207, n^o 3-4 (juillet 1992) : 303–14. http://dx.doi.org/10.1016/0040-1951(92)90392-j.

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Rollmann, Hans J. « Moravians in Central Labrador : The Indigenous Inuit Mission of Jacobus and Salome at Snooks Cove ». Journal of Moravian History 9, n^o 1 (2010) : 6–40. http://dx.doi.org/10.2307/41179879.

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Abstract The article documents Moravian efforts to extend missionary activities from coastal to central Labrador during the second half of the nineteenth century and highlights the evangelization of fellow Inuit at Snooks Cove near Rigolet in 1871/72 by the Hopedale Inuk Jacobus and several companions. The missionary activities of Jacobus are placed in the wider nineteenth-century Moravian context of stimulating increased aboriginal participation among mission churches worldwide. In Labrador, such greater involvement of Inuit in the life of their church was particularly encouraged by Bishop Levin Theodor Reichet, a member of the Unity Elders Conference in Germany, during and after his visitation journeys to Labrador in 1861 and 1874. Appended to the article is a translation from German of Jacobus's original Inuktitut account about his evangelistic activities at Snooks Cove.

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Norton, C. H., A. Cuerrier et L. Hermanutz. « People and Plants in Nunatsiavut (Labrador, Canada) : Examining Plants as a Foundational Aspect of Culture in the Subarctic ». Economic Botany 75, n^o 3-4 (1 novembre 2021) : 287–301. http://dx.doi.org/10.1007/s12231-021-09530-7.

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AbstractThis paper emphasizes the cultural value of plants in Nunatsiavut (Labrador, Canada), a self–governing Inuit region in the Subarctic. Via interviews with community members, we describe the links between plant usage and culture to understand the direct ways that plants are utilized for food, construction, gardening, and medicine, and to then link these uses to deeper cultural significance among three communities in Nunatsiavut (Hopedale, Postville, and Rigolet). Many plants were common amongst communities with a total of 66 taxa identified. About 75% of taxa were reported in at least two communities, corresponding to 95% of all responses. Edible plants were the most common reported usage, with emphasis on berry–producing taxa such as blueberry shrubs. Our study shows that a diversity of plants (i) support cultural activities; (ii) act as markers for historical events; (iii) highlight intergenerational exchange and valuing of plant knowledge; (iv) express the deep awareness that people have for their local environment; and (v) a medium for the expression of traditional values. The similarities in the plant responses among the communities suggest a shared body of plant knowledge. Our study supports the great cultural importance of plants in northern communities.

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Royse, K. R., et R. G. Park. « Emplacement of the Nain anorthosite : diapiric versus conduit ascent ». Canadian Journal of Earth Sciences 37, n^o 8 (1 août 2000) : 1195–207. http://dx.doi.org/10.1139/e00-025.

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Estimation of settling velocities of large orthopyroxene megacrysts, found within anorthosite intrusions, are calculated and compared with ascent rates achieved by diapirism and conduit propagation. Calculations suggest that diapirism is far too slow to be an appropriate ascent mechanism for anorthositic crystal mush and favour conduit emplacement. The intrusions of the Nain Plutonic Suite (NPS) are located along the Abloviak shear zone, which marks the boundary between the Nain and Churchill provinces, and within the zone of juxtaposition of the Saglek and Hopedale blocks of the Nain Province. These crustal weaknesses have probably controlled the emplacement and distribution of the intrusions. Contact relations between intrusions of anorthosite and their gneissic host rock provide evidence for two emplacement styles within the NPS, the first typified by strongly deformed and recrystallized rocks, and the second by an outer border zone of mafic rocks. It is proposed that these differences in intrusive style are due to differences in ductility contrast between the magma and its surrounding host rocks, such that those intrusions emplaced into the thermally softened shear zone have deformed margins, whereas those intruded into the cooler Archaean crust have undeformed margins.

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Gillis, Erin, Richard Wright, Victoria Mitchell et Nick Montevecchi. « Definition of the Churchill River Delta and its petroleum potential, offshore Labrador, Canada ». Interpretation 8, n^o 2 (1 mai 2020) : SH19—SH32. http://dx.doi.org/10.1190/int-2019-0091.1.

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Starting in 2011, a multiyear modern 2D long offset broadband seismic survey was acquired offshore Labrador, Canada, by TGS and PGS in partnership with Nalcor Energy. This regional survey covers the slope and deepwater portions of the margin. Three Mesozoic and Cenozoic-aged basins were informally defined from these data, the Chidley, Henley, and Holton; also, the poorly constrained Hawke Basin was remapped. The 2D data set imaged for the first time a very large Cenozoic-aged delta adjacent to the mouth of Lake Melville. We have mapped this delta on a [Formula: see text] 2D seismic grid. The delta is 5–8 km thick, and its aerial extent is [Formula: see text]. The age of this delta has been interpreted to be Eocene to Miocene. Adjacent to this Cenozoic delta on the Labrador shelf, there is a working petroleum system within the proximal Hopedale and Saglek Basins where there are five gas discoveries and one oil discovery. The modern long-offset 2D data set appears to indicate a working petroleum system within the newly mapped Cenozoic delta, and two phases of hydrocarbons may be present.

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Clark, Peter U., et William W. Fitzhugh. « Late Deglaciation of the Central Labrador Coast and Its Implications for the Age of Glacial Lakes Naskaupi and McLean and for Prehistory ». Quaternary Research 34, n^o 3 (novembre 1990) : 296–305. http://dx.doi.org/10.1016/0033-5894(90)90042-j.

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AbstractThe age of the marine limit and associated deglaciation has been estimated from relative sea-level curves for the Hopedale and Nain areas of the central Labrador coast as approximately 7600 ± 200 and 8500 ± 200 yr ago, respectively. These ages indicate that the ice margin remained on the coast for up to 3000 yr longer than previously estimated. Because the central coast is due east of glacial lakes Naskaupi and McLean, the earliest the lakes could have formed was <8500 ± 200 yr ago, with their largest phases being fully established only after 7600 ± 200 yr ago. This suggests that the age of the lakes, and associated deglaciation of the central Labrador-Ungava region, is younger by at least 1500 yr than previously estimated. A late-glacial marine-based ice mass in Ungava Bay that dammed the lakes collapsed ca. 7000 yr ago. Within this time frame, therefore, the glacial lakes only existed for <500 yr. The persistence of the Laurentide Ice Sheet margin on the central Labrador coast until 7600 yr ago probably restricted the northward movement of early prehistoric people into northern Labrador.

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Cadman, Andrew C., Larry Heaman, John Tarney, Richard Wardle et Thomas E. Krogh. « U–Pb geochronology and geochemical variation within two Proterozoic mafic dyke swarms, Labrador ». Canadian Journal of Earth Sciences 30, n^o 7 (1 juillet 1993) : 1490–504. http://dx.doi.org/10.1139/e93-128.

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An Early Proterozoic Kikkertavak mafic dyke intruding the Archaean Hopedale block, Labrador, gives an age of 2235 ± 2 Ma using U–Pb techniques on baddeleyite. A Harp mafic dyke in the same area gives an age of 1273 ± 1 Ma using U–Pb techniques on baddeleyite and zircon. The latter age is almost identical to that of the giant Mackenzie swarm and to the age of the BD0 dykes in South Greenland, and points to a major pulse of mafic magmatism over much of the North Atlantic craton at this time. The former age is a little older than available Rb–Sr ages for the extensive MD swarm in West Greenland, but there are possible correlatives.Geochemical data are presented to ascertain whether there are significant compositional differences between the Harp and Kikkertavak dyke swarms. In fact, two distinct chemical subgroups can be recognized within the Kikkertavak dykes, and three others are recognized within the Harp suite. These differences apply more to trace element patterns rather than major element abundances, but although there are compositional differences between the average Harp and average Kikkertavak dyke, it is unlikely that geochemistry could be used unequivocally to separate the two. The compositional differences probably reflect evolutionary processes in the lithosphere. The range of composition exemplified by the subgroups is most easily interpreted in terms of proportion of asthenosphere and lithosphere components, and does not necessarily imply that either dyke swarm was emplaced over a long period. The presence of subgroups within both swarms urges some caution in assuming all dykes correspond to one or other age.

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Bridgwater, D., et L. Schiøtte. « The Archaean gneiss complex of northern Labrador A review of current results, ideas and problems ». Bulletin of the Geological Society of Denmark 39 (20 décembre 1991) : 153–66. http://dx.doi.org/10.37570/bgsd-1991-39-06.

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1. The early Archaean rocks in northern Labrador can be subdivided into the ea. 3.78 Ga Nulliak supracrustal association, the migmatitic Uivak I gneisses, the dominant phase of which was emplaced at ea. 3.73 Ga, and the Uivak II augen gneiss. Inherited low-U rounded inclusions within igneous zircons in the Uivak I gneisses have ages between 3.73 and 3.86 Ga and are more likely to have been derived from a pre-existing high-grade metamorphic gneiss complex than from the Nulliak association. In the early Archaean there were probably several rapid cycles of sedimentary deposition and volcanism followed by emplacement of major plutons. Mid Archaean gneisses are more abundant in northern Labrador than previously realised. The late Archaean metamorphic history of these gneisses is different from the history of the early Archaean gneisses. Whereas an important part of the mid Archaean suite was emplaced in granulite facies and retrogressed at the time of granitoid veining at ea. 2.99 Ga, the major part of the early Archaean rocks were reworked under granulite facies conditions in a sequence of closely spaced events between 2. 7 and 2.8 Ga. The two groups of gneisses had different metamorphic histories until ea. 2.7 Ga, but late and post-tectonic granites of 2.5- 2. 7 Ga age cut across both. It is suggested that the terrane model in southern West Greenland can be extended to Labrador and that tectonic intercalation of early and mid Archaean gneisses took place around 2.7 Ga. Correlation between the Maggo gneisses around Hopedale, mid Archaean gneisses in northernmost Labrador and gneisses from the Akia terrane in West Greenland is suggested. Like the Malene supracrustals in West Greenland the Upernavik supracrustals in Labrador are composite associations, the youngest of which are thought to have been deposited around 2. 7 Ga.

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Schiøtte, L., W. Compston et D. Bridgwater. « U–Th–Pb ages of single zircons in Archaean supracrustals from Nain Province, Labrador, Canada ». Canadian Journal of Earth Sciences 26, n^o 12 (1 décembre 1989) : 2636–44. http://dx.doi.org/10.1139/e89-224.

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Ion-probe U–Pb dating of igneous zircons from an acid metavolcanite belonging to the Nulliak supracrustal association of the Saglek area, northern Labrador, suggests an original age of 3776 ± 8 Ma (2σ), interpreted as the deposition age of the volcanite. In accordance with the field model, this is slightly but significantly older than the previously obtained ion-probe U–Pb age of igneous zircons from the main phase of the Uivak gneisses, which carries inclusions of the supracrustal association. A secondary event of zircon growth recorded in the metavolcanite has a maximum age of 3065 ± 8 Ma (2σ).A metapelite belonging to the Weekes amphibolite supracrustal association of the Hopedale area south of Nain contains rounded, low-U zircons of 3258 ± 24 Ma (2σ) age. Occasional textural evidence suggests that some of these zircons are most likely detrital grains of igneous origin, in which case 3258 ± 24 Ma is a minimum age of the source from which the sediment was derived and a maximum age for the deposition of the sediment. However, the possibility that the age represents recrystallization of the sediment under high-grade conditions cannot be ruled out. A 2841 ± 5 Ma (2σ) age obtained on a younger generation of euhedrally zoned high-U zircons from the metapelite is within error of the published bulk zircon U–Pb age of the tonalitic component of the Kanairiktok plutonic suite that intrudes the older orthogneiss and supracrustal units in the area. These younger zircons are most likely to have grown during migmatization of the metasediment at the time of emplacement of the suite.The zircon data give no positive evidence to support correlation between the Nulliak supracrustals and the Weekes amphibolite association.

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Green, Sam, Stephen A. O’Connor, Deric E. L. Cameron, James E. Carter, William Goodman, Niklas Heinemann et Alexander P. Edwards. « Producing pore pressure profiles based on theoretical models in undrilled, deepwater frontier basins ». Interpretation 3, n^o 1 (1 février 2015) : SE13—SE32. http://dx.doi.org/10.1190/int-2014-0076.1.

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A working petroleum system was established on the shelf in offshore Labrador with the Bjarni H-81 discovery in 1973 in the Hopedale Basin. The same reservoirs as those targeted on the shelf are present in the deep water, which is currently receiving attention as the result of newly acquired seismic data. To date, only a very small number of wells have been drilled in the deep water, i.e., Blue H-28, Orphan Basin, and none off mainland Labrador. The wells that were drilled in the deep water had encountered significant overpressure, e.g., kicks that indicated overpressures of 26,850 kPa in the Mid-Cretaceous. Therefore, it was reasonable to assume that pore pressures be similarly high for any new deepwater prospects identified. To help reduce the risk in unexplored environments, we developed an approach that can be adopted to model pore pressure in deepwater settings, with Labrador as the main case study area featured, but also we discussed other global examples such as the Vøring Basin, Mid-Norway. Our results indicated, as a first approximation, that seismic velocity-based pore pressures in shale-rich intervals were similar to the geologic model down to the Lower Tertiary. Deep lithologies were, by regional analogue, likely affected by cementation that will act to preserve overpressure generated by disequilibrium compaction by reducing permeability but will not generate additional pore pressure. The cements (and any carbonate or volcanic lithologies) will, however, result in faster shales and will underpredict pore pressure by mimicking low porosity. A theoretical or “geologic modeling” approach can be used to sense-check any pore pressure interpretation from seismic velocity. The geologic approach also can be used to assess the risk for mechanical seal failure by allowing for estimates of the pore pressure, and related fracture pressure, to be made without the effects of cementation that affect the logs and seismic velocity data.

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Schiøtte, L., A. P. Nutman et D. Bridgwater. « U–Pb ages of single zircons within "Upernavik" metasedimentary rocks and regional implications for the tectonic evolution of the Archaean Nain Province, Labrador ». Canadian Journal of Earth Sciences 29, n^o 2 (1 février 1992) : 260–76. http://dx.doi.org/10.1139/e92-024.

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Detrital zircons and their postdepositional overgrowths from three units of the "Upernavik" supracrustal association in the northern (Saglek) block of the Archaean Nain Province have been dated with the ion microprobe SHRIMP. In one unit, from the granulite-facies area in inner Saglek Fiord, the zircon population is dominated by early Archaean grains thought to be derived from the Uivak gneisses. Recrystallization and growth of new zircon within this metasediment took place during granulite-facies metamorphism at 2761 ± 12 Ma (2σ), which is also a younger limit on the age of deposition.In a second unit, from the amphibolite-facies area in outer Saglek Fiord, detrital zircons have predominantly mid- and late Archaean ages. The mid-Archaean zircons are comparable in age to the 3235 Ma Lister gneisses. The ages of the late Archaean detrital zircons (2800–2960 Ma) do not correspond to any known rock complex in the Saglek block, but plutonic rocks associated or correlative with the ca. 2840 Ma Kanairiktok Plutonic Suite of the southern (Hopedale) block are a possible source for many of the grains. Overgrowths were dated at 2690–2730 Ma in this sample.A third metasedimentary unit from the Okak Bay area, 100 km south of Saglek Fiord, also contains detrital zircons with ages comparable to that of the Lister gneisses (3235 Ma). The age of recrystallization and zircon overgrowths was dated at ca. 2560 Ma in this sample. A single grain dated at ca. 2780 Ma is considered most likely to be detrital, which would imply an age of deposition between ca. 2780 and 2560 Ma for this unit.The results show that although late Archaean depositional ages are possible for all three units, the "Upernavik" supracrustal association is composite and sediments in different units have widely different sources and metamorphic histories. These conclusions support a new model for the Nain Province according to which separate terranes were tectonically juxtaposed in the late Archaean. In this model, the age of plutonic and supracrustal rocks and their metamorphic histories prior to juxtaposition differ from one terrane to another.

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Burley, David G. « Brumfield, William Craft. A History of Russian Architecture. Cambridge and New York : Cambridge University Press, 1993. Pp. x, 644. 80 colour plates, 677 halftones, map, index, bibliography. US $95.00 (cloth) Dimitriou, Harry T. Urban Transport Planning : A Developmental Model. London and New York : Routledge, 1992. Tables, figures, Index, bibliography. $115.50 (cloth) Spann, Edward K. Hopedale : From Commune to Company Town, 1840–1920. Columbus : Ohio State University Press, 1992. (Urban Life and Urban Landscape Series, Z.L. Miller and H.D. Shapiro, eds.) Pp. xiii, 213. Map, index, bibliography. US $37.50 (cloth) McBride, David. From TB to AIDS : Epidemics among Urban Blacks since 1900. Albany : State University of New York Press, 1991. (SUNY Series in Afro-American Studies, J. Howard and R.C. Smith, eds.) Pp. x, 234. Tables, figures, index. US $ 16.95 (paper) Rich, John, and Andrew Wallace-Hadrill, eds. City and Country in the Ancient World. (Leicester-Nottingham Studies in Ancient Society, vol. 2) London and New York : Routledge, 1991. Pp., xviii, 305. Maps, tables, figures, tables, index, bibliography. $23.95 (paper) Rich, John, ed. The City in Late Antiquity. (Leicester-Nottingham Studies in Ancient Society, vol. 3) London and New York : Routledge, 1992. Pp., x, 204. Maps, tables, figures, tables, index, bibliography. $65.00 (cloth) ». Urban History Review 22, n^o 1 (1993) : 58. http://dx.doi.org/10.7202/1016729ar.

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Wang, Yifeng, Robert Way et Jordan Beer. « Multi-decadal degradation and fragmentation of palsas and peat plateaus in coastal Labrador, northeastern Canada ». Environmental Research Letters, 8 octobre 2023. http://dx.doi.org/10.1088/1748-9326/ad0138.

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Abstract Peatland permafrost landforms, such as palsas and peat plateaus, often represent the most southern lowland permafrost occurrences in the Northern Hemisphere. While peatland permafrost is often found in continental conditions, over a thousand permafrost peatlands were recently identified along the previously understudied coastline of the Labrador Sea in northeastern Canada. The vulnerability of these landscapes to thaw is unknown but is expected to have hydrological and ecological impacts on important caribou habitat, the abundance of culturally relevant berries, and permafrost carbon storage. Using a combination of aerial photography (from 1948, 1985, 1992, 1994, and 2021) and high-resolution satellite imagery (from 2017, 2020, and 2021), we assess multi-decadal areal changes to peatland permafrost landforms at seven peatlands along the Labrador Sea coastline spanning from Red Bay (51.7° N) to north of Hopedale (55.7° N). Analyses reveal declines in permafrost extent of 33 to 93 % at individual sites, occurring at mean rates of 0.8 to 1.5 %/a. Permafrost loss was found to occur most rapidly at mixed palsa and peat plateau sites (mean rate of 1.4 %/a), followed by palsa sites (mean rate of 1.2 %/a) and peat plateau sites (mean rate of 0.9 %/a). Patterns of permafrost loss also differed between landform types, with more complete loss of individual landforms at palsa sites and more lateral and internal loss of existing landforms at peat plateau and mixed sites. This widespread degradation of peatland permafrost over the past 28 to 73 years is attributed to regional warming and peatland greening. Understanding recent change to permafrost peatlands in coastal Labrador is an important step towards predicting future habitat change in northeastern Canada and will inform regional land management in areas dominated by these culturally important landforms.

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« Edward K. Spann. Hopedale : From Commune to Company Town, 1840–1920. (Urban Life and Urban Landscape Series.) Columbus : Ohio State University Press. 1992. Pp. xiii, 213. $37.50 ». American Historical Review, juin 1994. http://dx.doi.org/10.1086/ahr/99.3.976-a.

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Lakra, Reshma, Pushpa Kumari et Subrata Mondal. « On the discovery of new sub-populations of <i>Bentinckia nicobarica</i> ; (Kurz) Becc. (Arecaceae) in Andaman Islands,India : Mapping and updated red list assessment ». Nelumbo, 27 juillet 2023. http://dx.doi.org/10.20324/nelumbo/v65/2023/172972.

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Bentinckia nicobarica (Kurz) Becc., a threatened palm is known to be strictly endemic to the Nicobar group of Islands as per IUCN Red list assessment 1998. It grows in the lowland rainforests close to the coastlines and fairly distributed all over in Nicobar group of Islands except Great Nicobar. Recently, new natural sub-populations of this species have been discovered from Alexandra Island, Boat Island, Hopeday Island, Redskin Island, Tarmugli Island and coast of Wandoor, South Andaman. The IUCN guideline has been used for the reassessment of its threat status which will help in prioritizing conservation.

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