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681.
Kuzmenko N. V. Tsyrlin V. A. Pliss M. G. 《Izvestiya Atmospheric and Oceanic Physics》2021,57(10):1271-1292
Izvestiya, Atmospheric and Oceanic Physics - It is known that in mammals living in climates other than tropical, hemoconcentration is usually observed in winter. The average modern person actively... 相似文献
682.
Summary Nickel-copper mineralization occurs near the base of a diorite intrusion close to its contact with hornfelsed Ordovician and Silurian shales and greywackes. The principal ore minerals are nickeline, gersdorffite, pyrrhotine, pentlandite and chalcopyrite with minor amounts of molybdenite, tellurobismutite, gold, sphalerite and argentopentlandite. Pyrite, marcasite, violarite and goethite also occur but are interpreted as later alteration products. Much of the pyrrhotine-rich mineralization at the base of the intrusion is in the form of blebs and interstitial aggregates with amphiboles, plagioclase feldspar, biotite, chlorite and quartz. Chalcopyrite-rich and nickeline-gersdorffite-rich mineralization occurs above this and immediately below unmineralized diorite in the form of patches, lenticular masses and stringers along joints and fractures.Whole rock and ore analyses and electron microprobe data on the silicates, sulphides and sulpharsenides are presented.The unmineralized diorite has low SiO2 and high MgO contents compared to typical diorites and relatively high Cr, Ni and Ti trace element values. In the mineralized diorite, platinum-group elements occur in very low concentrations in the pyrrhotineand chalcopyrite-rich assemblages but Pt, Pd and Au show significant enrichment in the nickeline-gersdorffite-rich mineralization.A magmatic origin for the mineralization is proposed rather than formation by hydrothermal solutions or metasomatism.
With 3 Figures 相似文献
Die nickel-kupfer vererzung von Talnotry, Newton Stewart, Schottland
Zusammenfassung Die Nickel-Kupfer Vererzung befindet sich im Kontaktbereich einer Dioritintrusion mit hornfelsdurchdrungenen silurischen und ordovizischen Grauwacken. Die am häufigsten auftretenden Erzmineralien sind Nickelin, Gersdorffit, Pyrrhotin, Pentlandit, und Chalcopyrit mit kleineren Mengen von Molybdenit, Tellurwismuth, Gold, Sphalerit und Argentopentlandit. Weiters treten als spätere Umwandlungsprodukte Pyrit, Markasit, Violarit und Goethit auf. Ein großer Teil der Pyrrhotin-reichen Vererzung am Fuße des eingedrungenen Diorits bildet fleckige, lückenfüllende Aggregate zwischen den Silikatphasen (Amphibol, Plagioklas, Biotit, Chlorit, Quarz). Die Chalcopyrit- und Nickelin-Gersdorffit-reiche Vererzung tritt zwischen dem unvererzten Diorit im Hangenden und der Pyrrhotin-reichen Vererzung im Liegenden als linsige, lappenartige Konzentration und entlang von Fugen und Brücken auf.Vollgesteins-Analysen sowie ausgewählte Erzanalysen und Mikrosondenergebnisse der Silikate, Sulfide und Sulfarsenide liegen vor.Im Unterschied zu den typischen Dioriten zeigt der unvererzte Diorit einen niedrigen SiO2 und hohen MgO Gehalt und relativ hohe Cr, Ni und Ti Spurenelementwerte. Die Platingruppenelemente sind in den Pyrrhotin- und Chalcopyrit-reichen Vererzungen nur schwach vertreten, jedoch sind Pt, Pd und An in der Gersdorffit-reichen Vererzung stark angereichert.Ein magmatischer Ursprung dieser Vererzung, im Gegensatz zu einer metasomatischen Entstehung oder Bildung aus hydrothermalen Lösungen wird vermutet.
With 3 Figures 相似文献
683.
684.
A. A. Zhamaletdinov A. N. Shevtsov E. P. Velikhov A. A. Skorokhodov V. E. Kolesnikov T. G. Korotkova P. A. Ryazantsev B. V. Efimov V. V. Kolobov M. B. Barannik P. I. Prokopchuk V. N. Selivanov Yu. A. Kopytenko E. A. Kopytenko V. S. Ismagilov M. S. Petrishchev P. A. Sergushin P. E. Tereshchenko B. V. Samsonov M. A. Birulya M. Yu. Smirnov T. Korja Yu. M. Yampolski A. V. Koloskov N. A. Baru S. V. Poljakov A. V. Shchennikov G. I. Druzhin W. Jozwiak J. Reda Yu. G. Shchors 《Izvestiya Atmospheric and Oceanic Physics》2015,51(8):826-857
685.
Guiomar Rotllant Carles G. Simeó Guillermo Guerao Marta Sastre Daniel F. R. Cleary Ricardo Calado Alicia Estévez 《Marine Ecology》2014,35(3):298-307
The spider crab Maja brachydactyla is an important commercial species in Europe and supports intensive fisheries in the NE Atlantic. A field survey was performed to assess long‐term and consecutive interannual (2005–2010) variation of the biochemical composition of newly hatched larvae of M. brachydactyla. Larval biochemical profiles differed significantly among years, with pronounced differences being recorded in 2010. Differences among batches of newly hatched larvae were mainly explained by the contribution of triacylglycerols and, to a lesser degree, by protein and lipid content. The use of different nutrition indices is discussed. The biochemical composition of newly hatched larvae from M. brachydactyla was highly variable, even though surveyed broodstock was obtained from the same local population and was always sampled during the same season. The unpredictable biochemical profiles of newly hatched larvae may condition their survival and recruitment. This largely overlooked aspect of larval variability should be considered in future fisheries management strategies and captive production of marine organisms that still rely on wild seeds. 相似文献
686.
Reservoir potential of Late Cretaceous terrestrial to shallow marine sandstones,Taranaki Basin,New Zealand 总被引:2,自引:0,他引:2
Late Cretaceous coals and coaly source rocks are the main source of hydrocarbons in the Taranaki Basin, yet to date there have not been any hydrocarbon discoveries within Cretaceous strata, and sandstone distribution and reservoir quality for this interval have been poorly understood. The Late Cretaceous sediments were deposited in several sub-basins across Taranaki, with their distribution largely determined by sediment supply, subsidence, and sea level change. In this study, we describe potential reservoir facies in well penetrations of Cretaceous strata in Taranaki, as well as from outcrop in northwest Nelson, on the southern edge of the basin. 相似文献
687.
This paper discusses the impact of local and national policies in the Philippines on the participation of indigenous peoples in relation to fisheries management. Specifically, this research focuses on the Tagbanua, an indigenous group in Coron Island, Palawan, on the western side of the Philippines. The struggle of the Tagbanua in reclaiming their ancestral title to the land and sea reflects broader moves toward self-determination, which is critical not only to their ancestral lands and waters, but also to their survival. Indigenous rights are essential in addressing social justice and in giving a greater voice that encourages indigenous peoples towards self-governing institutions and common management of resources. Significantly, the fundamental development of indigenous peoples lies in the recognition of their rights in their ancestral domain and the preservation of their culture, tradition, system, practices and their natural resources. This paper examines the Tagbanua experience, through a critical exploration of institutions and property rights, with attention to corresponding effects in reducing conflict with other stakeholders in the area, and in affecting the sustainability of fishery resources. 相似文献
688.
Feng Ding Volkhard Spiess Ian R. MacDonald Markus Brüning Noemi Fekete Gerhard Bohrmann 《Marine and Petroleum Geology》2010,27(4):959-972
During German R/V Meteor M67/2 expedition to Campeche Knolls, southern Gulf of Mexico, a set of 2D high resolution seismic data was acquired to study the near-surface sediment structure and its relationship with hydrocarbon seepages in this salt province. The comprehensive survey covered 20 individual bathymetric highs or ridges and identified three principle structural types: Passive Type, Chaopopte Type, and Asymmetric Flap Type. The first type is the result of passive diapirism, whereas the latter two were initialized by a regional compressional event in the Miocene, but are later differently modified by salt tectonism. Chapopote Type structures appear as symmetrical domes, with uplifted coarse-grained Miocene sediments in their cores and rather thin syn-kinematic sediments covering the crests. Asymmetric Flap Type structures are also first folded as domes or ridges, but one flap later subsided together with salt evacuation, resulting in single uplifted monoclines. With the coarse-grained pre-kinematic sediments as reservoir units, both structural types can focus and accumulate hydrocarbons. The geometries of the structures suggest that hydrocarbons are accumulated in the center of the Chapopote Type structures and in the subsided flaps of the Asymmetric Flap Type structures. Hydrocarbon leakage from these thinly sealed reservoirs is regarded as the principle mechanism for the seepage in the study area, and accordingly the most seepage-prone positions are above these reservoirs. The seep locations suggested by analysis of sea-surface oil slick images of SAR satellite data are also examined in this study. These independently derived seep locations confirm the seepage-prone positions to be above the shallow buried reservoirs. This study suggest that the shallow sediment structures control the distribution of the hydrocarbon seeps of the north-western Campeche Knolls, although the hydrocarbons are sourced from the greater depth. 相似文献
689.
G. N. Baturin 《Oceanology》2010,50(1):83-92
The ferromanganese concretions spread at the bottom of the shallow northwestern part of the Black Sea are mainly represented
by Fe and Mn hydrate nodules on shells and substituted worm tubes. The element composition of these formations was found by
the methods of chemical, atomic-absorbtion, neutron activation, and plasmic (ICP-MS) analyses. It is established that the
content and the ratio of Fe and Mn in the concretions ranges within considerable limits, which controls the occurrence of
several associated iron-free metals and microelements, some which have not been previously studied in the Black Sea concretions. 相似文献
690.
This paper studies the causes and mechanisms of the formation of extreme anomalies in the tropospheric temperature associated
with the North Atlantic Oscillation (NAO). Our approach is based on understanding that, in the annual cycle, continental-scale
tropospheric temperature anomalies (planetary waves with longitudinal wave numbers of 1–3) can both intensify under the direct
action of heat inflow as an energy source for these anomalies (radiation cooling/heating) and weaken as a result of the destructive
action of heat inflow under temperature advections with the opposite (to the heat inflow) sign [4, 5]. According to the monthly
mean data of the NCEP/NCAR reanalysis over the 40-year period, seasonal air temperature anomalies have been studied at the
level 850 hPa (T
850) in different regions of Eurasia. It has been confirmed that the negative NAO phase in winter is favorable for preserving
negative T
850 anomalies in the east of the continent at this time of year, whereas the positive NAO phase is favorable for negative T
850 anomalies in the west. However, it has been revealed that this dependence was critically violated during the winter seasons
approximately two years before an extreme event. This was explained by the fact that, in those years, the NAO influence on
winter T
850 anomalies was limited. This paper formally considers a certain mechanism of anomalous heat inflow as an energy source for
these anomalies with functions of the formation (intensification) of negative T
850 anomalies in winter and positive T
850 anomalies in summer, as well as with a function of the limitation of the influence of the predominant dynamic mode on some
regions of the continent. It is shown that, in the 1960s, T
850 anomalies with negative NAO indices in the east of the continent were governed by a hypothetic mechanism of heat inflow as
an energy source for anomalies; in 1980s, at prolonged positive NAO indices, T
850 anomalies in the west of the continent could also be governed by this mechanism. This paper, within the accepted degree of
detail, demonstrates the process of limitation of the NAO influence in some years (1966, 1967, 1987, and 1988), which leads
to an unbalance of the anomalies and a possible extreme phenomenon. It is demonstrated that, in some seasons, the anomalies
were not governed by the hypothetic mechanism of the heat inflow under the action of large NAO changes and a complete upset
of the annual cycle of anomalies. Determining the first indicators of the unbalance, which can lead to extreme anomalies,
is shown to be difficult if it is based only on an analysis of winter seasons (as is the case with most of the works) without
invoking the annual trends of the tropospheric temperature and the NAO index. 相似文献