The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias...The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent paragneiss.The mineralization is associated with a dyke-like body which is termed the feeder dyke.This dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps Intrusion.Where the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps Intrusion.The Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide mineralization.The Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are mineralized.The Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day surface.It is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/Co of sulfide between the two.The boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, development of barren olivine gabbro, and by a change from typically massive sulfides and breccias sulfides into more typical variable-textured troctolites with heavy to weak disseminated sulfide.Sulfides hosted in the feeder dyke tend to have low metal tenors ([Ni]100=2.5%-3.5%); sulfides in Eastern Deeps massive and breccia ores have intermediate Ni tenors ([Ni]100=3.5%-4%) and disseminated sulfides in overlying rocks have high Ni tenors ([Ni] 100=4%-8%) . Conduit-hosted mineralization and mineral zones in the paragneiss adjacent to the Reid Brook Deposit tend to have lower Ni tenor than the Ovoid and Eastern Deeps Deposits.The tenor of mineral hosted in the country rock gneisses tends to be the same as that developed in the conduit ; the injection of the sulfide into the country rocks likely occurred before formation of monosulfide solid solution.The Ovoid Deposit is characterized by coarse-grained loop-textured ores consisting of 10cm-2msized pyrrhotite crystals separated by chalcopyrite and pentlandite.A small lens of massive cubanite surrounded by more magnetite-rich sulfide assemblages represents what appears to be the product of in-situ sulfide fractionation. Detailed exploration in the area between the Reid Brook Zone and the Eastern Deeps has shown that these intrusions and ore deposits are connected by a branched dyke and chamber system in a major westeast fault zone.The Eastern Deeps chamber may be controlled by graben-like fault structures , and the marginal structures appear to have controlled dykes which connect the chambers at different levels in the crust.The geological relationships in the intrusion are consistent with emplacement of the silicate and sulfide laden magma from a deeper sub-chamber (possibly a deep eastward extension of the Western Deeps Intrusion where S-saturation was initially achieved) .The silicate and sulfide magmas were likely emplaced through this conduit into the Eastern Deeps intrusion as a number of different fragment laden pulses of sulfide-silicate melt that evolved with different R factors and in response to some variation in the degree of evolution of the parental magma.S isotope and S/Se data coupled with geological evidence point to a crustal source for the sulfur , and the site of equilibration of mafic magma and crustal S is placed at depth in a sulfidic Tasiuyak Gneiss. The structural control on emplacement of small intrusions with transported sulfide is a feature found in different nickel sulfide deposits around the world.Champagne glass-shaped openings in sub-vertical chonoliths are a common morphology for this deposit type (e.g.the Jinchuan , Huangshan , Huangshandong , Jingbulake , Limahe , Hong Qi Ling deposits in China , the Eagle deposits in the United States , and the Double Eagle deposit in Canada) .Some of the structures of the Midcontinent Rift of North America also host Ni-Cu-(PGE) deposits of this type (e.g.the Current Lake Complex in the Quetico Fault Zone in Ontario , Canada and the Tamarac mineralisation in the Great Lakes Structural Zone of the United States) .Other major nickel deposits associated with flat structures adjacent to major mantle-penetrating structures include the Noril'sk , Noril'sk II , Kharaelakh , NW Talnakh , and NE Talnakh Intrusions of the Noril'sk Region of Russia , the Kalatongke deposit in NW China , and Babel-Nebo in Western Australia.These deposits are all formed in mantle-penetrating structural conduits that link into the roots of large igneous provinces near the edges of old cratons.展开更多
The role of winter sea-ice in the Labrador Sea as a precursor for precipitation anomalies over southeastern North America and Western Europe in the following spring is investigated. In general terms, as the sea ice in...The role of winter sea-ice in the Labrador Sea as a precursor for precipitation anomalies over southeastern North America and Western Europe in the following spring is investigated. In general terms, as the sea ice increases, the precipitation also increases. In more detail, however, analyses indicate that both the winter sea-ice and the sea surface temperature(SST)anomalies related to increases in winter sea-ice in the Labrador Sea can persist into the following spring. These features play a forcing role in the spring atmosphere, which may be the physical mechanism behind the observational relationship between the winter sea-ice and spring precipitation anomalies. The oceanic forcings in spring include Arctic sea-ice anomalies and SST anomalies in the tropical Pacific and high-latitude North Atlantic. Multi-model Coupled Model Intercomparison Project Phase 5 and Atmospheric Model Intercomparison Project simulation results show that the atmospheric circulation response to the combination of sea-ice and SST is similar to that observed, which suggests that the oceanic forcings are indeed the physical reason for the enhanced spring precipitation. Sensitivity experiments conducted using an atmospheric general circulation model indicate that the increases in precipitation over southeastern North America are mainly attributable to the effect of the SST anomalies, while the increases over Western Europe are mainly due to the sea-ice anomalies. Although model simulations reveal that the SST anomalies play the primary role in the precipitation anomalies over southeastern North America, the observational statistical analyses indicate that the area of sea-ice in the Labrador Sea seems to be the precursor that best predicts the spring precipitation anomaly.展开更多
Deep convection in the Labrador Sea is confined within a small region in the southwest part of the basin.The strength of deep convection in this region is related to the local atmospheric and ocean characteristics,whi...Deep convection in the Labrador Sea is confined within a small region in the southwest part of the basin.The strength of deep convection in this region is related to the local atmospheric and ocean characteristics,which favor processes of deep convection preconditioning and intense air-sea exchange during the winter season.In this study,we explored the effect of eddy-induced flux transport on the stratification of the Labrador Sea and the properties of deep convection.Simulations from an eddy-resolving ocean model are presented for the Labrador Sea.The general circulation was well simulated by the model,including the seasonal cycle of the deep Labrador Current.The simulated distribution of the surface eddy kinetic energy was also close to that derived from Topex-Poseidon satellite altimeter data,but with smaller magnitude.The energy transfer diagnostics indicated that Irminger rings are generated by both baroclinic and barotropic processes; however,when they propagate into the interior basin,the barotropic process also disperses them by converting the eddy energy to the mean flow.In contrast to eddy-permitting simulations,deep convection in the Labrador Sea was better represented in the eddyresolving model regarding their lateral position.Further analysis indicated that the improvement might be due to the lateral eddy flux associated with the resolved Irminger rings in the eddy-resolving model,which contributes to a realistic position of the isopycnal dome in the Labrador Sea and correspondingly a realistic site of deep convection.展开更多
An overview of the seasonal variation of sea-ice cover in Baffin Bay and the Labrador Sea is given. A coupled ice-ocean model, CECOM, has been developed to study the seasonal variation and associated ice-ocean process...An overview of the seasonal variation of sea-ice cover in Baffin Bay and the Labrador Sea is given. A coupled ice-ocean model, CECOM, has been developed to study the seasonal variation and associated ice-ocean processes. The sea-ice component of the model is a multi-category ice model in which mean concentration and thickness are expressed in terms of a thickness distribution function. Ten categories of ice thickness are specified in the model. Sea ice is coupled dynamically and thermodynamically to the Princeton Ocean Model. Selected results from the model including the seasonal variation of sea ice in Baffin Bay, the North Water polynya and ice growth and melt over the Labrador Shelf are presented.展开更多
For a period of two years, a survey of 110 parturitions of Labrador breed bitches was carried out in Rosario City to determine the average number of puppies per litter, percentage of dystocia of all parturitions, perc...For a period of two years, a survey of 110 parturitions of Labrador breed bitches was carried out in Rosario City to determine the average number of puppies per litter, percentage of dystocia of all parturitions, percentage of males and females born and causes of dystocia, as well as the incidence of clinically detectable congenital pathologies. Over a total of 110 parturitions ninety three （84.5%） parturitions were normal and 17 （15.5%） were dystocic ones, it was established that atony 1 was the most numerous cause of dystocia （53%）, followed by atony 2 （23%）, dystocia by fetal disorders （6%）, hydramnios （6%）, uterine rupture （6%） and vagina fibrous band （6%）. The whole puppies born was 866, 7.9 puppies per litter, if comparison between normal parturitions and dystocic ones is made, numbers are 7.05 and 8.02 respectively. When sex evaluation percentage is made 51.5% are males and 48.5% are females. When viability of puppies born is calculated it is established that in ones born by normal parturition perinatal death was 9.3%, while in those born by dystocia it was 10.9%. Among clinically verifiable congenital disorders low weight at birth was the most frequent congenital alteration, followed by cleft palate, lethal congenital edema or walrus syndrome and hare lip.展开更多
目的探究社会性不同的拉布拉多犬认知能力是否存在差异。方法参照瑞典工作犬协会(the Swedish Working Dog Association)创建的犬气质评估测试(dog mentality assessment,DMA),使用DMA测试中的社会接触、游戏Ⅰ、距离游戏、扮鬼和游戏Ⅱ...目的探究社会性不同的拉布拉多犬认知能力是否存在差异。方法参照瑞典工作犬协会(the Swedish Working Dog Association)创建的犬气质评估测试(dog mentality assessment,DMA),使用DMA测试中的社会接触、游戏Ⅰ、距离游戏、扮鬼和游戏Ⅱ5个子测试中的12个行为变量来评估犬的社会性,根据评分标准对中国导盲犬大连培训基地提供的49只拉布拉多犬的社会性行为变量进行评分,使用聚类分析将其分为社会性高分组(n=15)和低分组(n=34)。根据Bray等的犬认知发展系列测试(dog cognitive development battery,DCDB)建立了新的犬认知能力测试体系,对犬的社会线索使用、无法解决任务、抑制控制、认知灵活、工作记忆和多步骤解决任务等不同领域的认知能力进行测试,记录犬在测试中的行为表现及持续时长,统计分析社会性不同的犬认知能力是否存在差异。结果社会性高分组与低分组的犬在无法解决任务、抑制控制测试和多步骤解决任务中的行为变量上存在显著差异。在无法解决任务中,社会性高分组的犬注视人时长显著高于社会性低分组的犬(P=0.008),注视人潜伏时长显著低于社会性低分组的犬(P=0.0001)。在抑制控制测试中,社会性高分组的犬选择正确率显著高于社会性低分组的犬(P=0.034),选择时长显著低于社会性低分组的犬(P=0.039)。在多步骤解决任务中,社会性高分组的犬完成木桩任务数量显著高于社会性低分组的犬(P=0.044);操作木桩时长占比显著低于社会性低分组的犬(P=0.05);完成骨头盘任务平均时长显著高于社会性低分组的犬(P=0.037);操作骨头盘时长占比显著低于社会性低分组的犬(P=0.038)。涉及可操作仪器的测试中,社会性高分组的犬注视人时长高于社会性低分组的犬,操作仪器时长低于低分组的犬,但经统计无显著差异(P>0.05)。结论社会性不同的犬的认知能力存在差异。社会性好的拉布拉多犬表现出更强的认知能力,它们在测试时抑制冲动的能力更强,完成多步骤解决任务的能力更强,在遇到无法解决任务时更倾向于转变策略向人寻求新线索而不是执着于操作仪器。展开更多
文摘The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, Canada.The Ni-Cu-Co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent paragneiss.The mineralization is associated with a dyke-like body which is termed the feeder dyke.This dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps Intrusion.Where the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps Intrusion.The Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide mineralization.The Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are mineralized.The Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day surface.It is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/Co of sulfide between the two.The boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, development of barren olivine gabbro, and by a change from typically massive sulfides and breccias sulfides into more typical variable-textured troctolites with heavy to weak disseminated sulfide.Sulfides hosted in the feeder dyke tend to have low metal tenors ([Ni]100=2.5%-3.5%); sulfides in Eastern Deeps massive and breccia ores have intermediate Ni tenors ([Ni]100=3.5%-4%) and disseminated sulfides in overlying rocks have high Ni tenors ([Ni] 100=4%-8%) . Conduit-hosted mineralization and mineral zones in the paragneiss adjacent to the Reid Brook Deposit tend to have lower Ni tenor than the Ovoid and Eastern Deeps Deposits.The tenor of mineral hosted in the country rock gneisses tends to be the same as that developed in the conduit ; the injection of the sulfide into the country rocks likely occurred before formation of monosulfide solid solution.The Ovoid Deposit is characterized by coarse-grained loop-textured ores consisting of 10cm-2msized pyrrhotite crystals separated by chalcopyrite and pentlandite.A small lens of massive cubanite surrounded by more magnetite-rich sulfide assemblages represents what appears to be the product of in-situ sulfide fractionation. Detailed exploration in the area between the Reid Brook Zone and the Eastern Deeps has shown that these intrusions and ore deposits are connected by a branched dyke and chamber system in a major westeast fault zone.The Eastern Deeps chamber may be controlled by graben-like fault structures , and the marginal structures appear to have controlled dykes which connect the chambers at different levels in the crust.The geological relationships in the intrusion are consistent with emplacement of the silicate and sulfide laden magma from a deeper sub-chamber (possibly a deep eastward extension of the Western Deeps Intrusion where S-saturation was initially achieved) .The silicate and sulfide magmas were likely emplaced through this conduit into the Eastern Deeps intrusion as a number of different fragment laden pulses of sulfide-silicate melt that evolved with different R factors and in response to some variation in the degree of evolution of the parental magma.S isotope and S/Se data coupled with geological evidence point to a crustal source for the sulfur , and the site of equilibration of mafic magma and crustal S is placed at depth in a sulfidic Tasiuyak Gneiss. The structural control on emplacement of small intrusions with transported sulfide is a feature found in different nickel sulfide deposits around the world.Champagne glass-shaped openings in sub-vertical chonoliths are a common morphology for this deposit type (e.g.the Jinchuan , Huangshan , Huangshandong , Jingbulake , Limahe , Hong Qi Ling deposits in China , the Eagle deposits in the United States , and the Double Eagle deposit in Canada) .Some of the structures of the Midcontinent Rift of North America also host Ni-Cu-(PGE) deposits of this type (e.g.the Current Lake Complex in the Quetico Fault Zone in Ontario , Canada and the Tamarac mineralisation in the Great Lakes Structural Zone of the United States) .Other major nickel deposits associated with flat structures adjacent to major mantle-penetrating structures include the Noril'sk , Noril'sk II , Kharaelakh , NW Talnakh , and NE Talnakh Intrusions of the Noril'sk Region of Russia , the Kalatongke deposit in NW China , and Babel-Nebo in Western Australia.These deposits are all formed in mantle-penetrating structural conduits that link into the roots of large igneous provinces near the edges of old cratons.
基金supported by the Natural Science Foundation of China (Grant Nos.41305064 and 41375085)a strategic project of the Chinese Academy of Sciences (Grant No.XDA11010401)the China Scholarship Council
文摘The role of winter sea-ice in the Labrador Sea as a precursor for precipitation anomalies over southeastern North America and Western Europe in the following spring is investigated. In general terms, as the sea ice increases, the precipitation also increases. In more detail, however, analyses indicate that both the winter sea-ice and the sea surface temperature(SST)anomalies related to increases in winter sea-ice in the Labrador Sea can persist into the following spring. These features play a forcing role in the spring atmosphere, which may be the physical mechanism behind the observational relationship between the winter sea-ice and spring precipitation anomalies. The oceanic forcings in spring include Arctic sea-ice anomalies and SST anomalies in the tropical Pacific and high-latitude North Atlantic. Multi-model Coupled Model Intercomparison Project Phase 5 and Atmospheric Model Intercomparison Project simulation results show that the atmospheric circulation response to the combination of sea-ice and SST is similar to that observed, which suggests that the oceanic forcings are indeed the physical reason for the enhanced spring precipitation. Sensitivity experiments conducted using an atmospheric general circulation model indicate that the increases in precipitation over southeastern North America are mainly attributable to the effect of the SST anomalies, while the increases over Western Europe are mainly due to the sea-ice anomalies. Although model simulations reveal that the SST anomalies play the primary role in the precipitation anomalies over southeastern North America, the observational statistical analyses indicate that the area of sea-ice in the Labrador Sea seems to be the precursor that best predicts the spring precipitation anomaly.
基金funded by the Canadian Foundation for Climate and Atmospheric Science through projects GOAPP and GR-631 and NSERCThe support of ACEnet (the Atlantic Computational Excellence Network), which provided the computing assistance for this work
文摘Deep convection in the Labrador Sea is confined within a small region in the southwest part of the basin.The strength of deep convection in this region is related to the local atmospheric and ocean characteristics,which favor processes of deep convection preconditioning and intense air-sea exchange during the winter season.In this study,we explored the effect of eddy-induced flux transport on the stratification of the Labrador Sea and the properties of deep convection.Simulations from an eddy-resolving ocean model are presented for the Labrador Sea.The general circulation was well simulated by the model,including the seasonal cycle of the deep Labrador Current.The simulated distribution of the surface eddy kinetic energy was also close to that derived from Topex-Poseidon satellite altimeter data,but with smaller magnitude.The energy transfer diagnostics indicated that Irminger rings are generated by both baroclinic and barotropic processes; however,when they propagate into the interior basin,the barotropic process also disperses them by converting the eddy energy to the mean flow.In contrast to eddy-permitting simulations,deep convection in the Labrador Sea was better represented in the eddyresolving model regarding their lateral position.Further analysis indicated that the improvement might be due to the lateral eddy flux associated with the resolved Irminger rings in the eddy-resolving model,which contributes to a realistic position of the isopycnal dome in the Labrador Sea and correspondingly a realistic site of deep convection.
文摘An overview of the seasonal variation of sea-ice cover in Baffin Bay and the Labrador Sea is given. A coupled ice-ocean model, CECOM, has been developed to study the seasonal variation and associated ice-ocean processes. The sea-ice component of the model is a multi-category ice model in which mean concentration and thickness are expressed in terms of a thickness distribution function. Ten categories of ice thickness are specified in the model. Sea ice is coupled dynamically and thermodynamically to the Princeton Ocean Model. Selected results from the model including the seasonal variation of sea ice in Baffin Bay, the North Water polynya and ice growth and melt over the Labrador Shelf are presented.
文摘For a period of two years, a survey of 110 parturitions of Labrador breed bitches was carried out in Rosario City to determine the average number of puppies per litter, percentage of dystocia of all parturitions, percentage of males and females born and causes of dystocia, as well as the incidence of clinically detectable congenital pathologies. Over a total of 110 parturitions ninety three （84.5%） parturitions were normal and 17 （15.5%） were dystocic ones, it was established that atony 1 was the most numerous cause of dystocia （53%）, followed by atony 2 （23%）, dystocia by fetal disorders （6%）, hydramnios （6%）, uterine rupture （6%） and vagina fibrous band （6%）. The whole puppies born was 866, 7.9 puppies per litter, if comparison between normal parturitions and dystocic ones is made, numbers are 7.05 and 8.02 respectively. When sex evaluation percentage is made 51.5% are males and 48.5% are females. When viability of puppies born is calculated it is established that in ones born by normal parturition perinatal death was 9.3%, while in those born by dystocia it was 10.9%. Among clinically verifiable congenital disorders low weight at birth was the most frequent congenital alteration, followed by cleft palate, lethal congenital edema or walrus syndrome and hare lip.
文摘目的探究社会性不同的拉布拉多犬认知能力是否存在差异。方法参照瑞典工作犬协会(the Swedish Working Dog Association)创建的犬气质评估测试(dog mentality assessment,DMA),使用DMA测试中的社会接触、游戏Ⅰ、距离游戏、扮鬼和游戏Ⅱ5个子测试中的12个行为变量来评估犬的社会性,根据评分标准对中国导盲犬大连培训基地提供的49只拉布拉多犬的社会性行为变量进行评分,使用聚类分析将其分为社会性高分组(n=15)和低分组(n=34)。根据Bray等的犬认知发展系列测试(dog cognitive development battery,DCDB)建立了新的犬认知能力测试体系,对犬的社会线索使用、无法解决任务、抑制控制、认知灵活、工作记忆和多步骤解决任务等不同领域的认知能力进行测试,记录犬在测试中的行为表现及持续时长,统计分析社会性不同的犬认知能力是否存在差异。结果社会性高分组与低分组的犬在无法解决任务、抑制控制测试和多步骤解决任务中的行为变量上存在显著差异。在无法解决任务中,社会性高分组的犬注视人时长显著高于社会性低分组的犬(P=0.008),注视人潜伏时长显著低于社会性低分组的犬(P=0.0001)。在抑制控制测试中,社会性高分组的犬选择正确率显著高于社会性低分组的犬(P=0.034),选择时长显著低于社会性低分组的犬(P=0.039)。在多步骤解决任务中,社会性高分组的犬完成木桩任务数量显著高于社会性低分组的犬(P=0.044);操作木桩时长占比显著低于社会性低分组的犬(P=0.05);完成骨头盘任务平均时长显著高于社会性低分组的犬(P=0.037);操作骨头盘时长占比显著低于社会性低分组的犬(P=0.038)。涉及可操作仪器的测试中,社会性高分组的犬注视人时长高于社会性低分组的犬,操作仪器时长低于低分组的犬,但经统计无显著差异(P>0.05)。结论社会性不同的犬的认知能力存在差异。社会性好的拉布拉多犬表现出更强的认知能力,它们在测试时抑制冲动的能力更强,完成多步骤解决任务的能力更强,在遇到无法解决任务时更倾向于转变策略向人寻求新线索而不是执着于操作仪器。
