The Paleoproterozoic porphyry copper–molybdenum deposit of Kourki (Liptako Province, western Niger)

2020 ◽  
pp. SP502-2019-139
Author(s):  
Mallam Mamane Hallarou ◽  
Moussa Konaté ◽  
Akinade Shadrach Olatunji ◽  
Yacouba Ahmed
Keyword(s):  
Close Contact ◽  
Porphyry Copper ◽  
Porphyry Cu ◽  
The North ◽  
Andean Cordillera ◽  
Reflected Light ◽  
Geochemical Study ◽  
Propylitic Alteration ◽  
Set Up ◽  
The One

AbstractThe Kourki porphyry Cu–Mo deposit is located in the southern part of the Gorouol greenstone belt in Western Niger. The potential Cu–Mo mineralization is hosted by granitoids (granodiorite and diorite) and veins, in Paleoproterozoic plutonic rocks, which are the main porphyry Cu–Mo system. The scientific objective of this study was to determine the characteristics of Kourki Cu–Mo mineralization and to compare them with other porphyry systems in the world and particularly with those of the West African Craton. The methods implemented consist of a field study and a polarizing microscope analysis in transmitted and reflected light on the rocks bearing Cu–Mo mineralization. The use of reference diagrams made it possible, on the one hand, to confirm the origin of the Cu–Mo mineralization and, on the other hand, to specify conditions of the formation of this mineralization. The geology of the study area shows a granodiorite–tonalite pluton in close contact with dioritic intrusions to the north, clastic sediments to the east, and volcano-sedimentary rocks to the SE. The pluton is crosscut by an intrusion of molybdenum porphyry dyke with irregular shape that can be observed in outcrop. The geochemical study shows that the granodiorite–tonalite pluton can be related to a calc-alkaline plutonic series which characterizes an arc type environment. Large areas of hydrothermal quartz breccia have been identified within the pluton. They were set up by hydraulic fracturing along the zones of weakness. Most of the Cu–Mo mineralization in the Kourki deposit occurs as hydrothermal breccia, filled with veins, and was disseminated in the porphyry diorite and quartz–diorite stockworks. The mineralogical assemblage is marked by a predominance of pyrite, molybdenite, chalcopyrite and quartz with some bornite and chalcocite. The alterations include potassic alteration, propylitic alteration, sericitization and epidotization. All of these data show that the Kourki porphyry represents a characteristic system of an environmental arc, quite comparable with that of the Andean Cordillera.

Numerical Analysis of Ebb Water Split Ratio of the South and North Branch in the Changjiang Estuary

2013 ◽  
Vol 807-809 ◽  
pp. 1624-1627
Author(s):  
Ji Zhong Yang ◽  
Jie Gu ◽  
Dan Qing Ma ◽  
Xiao Li Wang ◽  
Tian Hu ◽  
...  
Keyword(s):  
Spring Tide ◽  
Changjiang Estuary ◽  
The South ◽  
The Changjiang Estuary ◽  
Hydrodynamic Analysis ◽  
The North ◽  
Split Ratio ◽  
Calculation Results ◽  
Set Up ◽  
The One

The change of water split ratio has important impacts on the fluvial process, saltwater intrusion and navigation in estuary area. A 2D hydrodynamics numerical model of the Changjiang Estuary was set up using Delft3D-FLOW. The calculation results are consistent well with the real measured data, which indicates that the model can be used in hydrodynamic analysis. Simulation results show that the ebb water split ratio of the North Branch in the flood season is larger than that in the dry season, while the situation of the South Branch is opposite. Under the condition of different tidal types, the ebb water split ratio for the North Branch is maximum during the spring tide, and minimum during the neap tide, while the one during the middle tide takes the second place.

Protracted Magmatism and Mineralized Hydrothermal Activity at the Gibraltar Porphyry Copper-Molybdenum Deposit, British Columbia

2020 ◽  
Vol 115 (5) ◽  
pp. 1119-1136 ◽  
Author(s):  
Christopher Kobylinski ◽  
Keiko Hattori ◽  
Scott Smith ◽  
Alain Plouffe
Keyword(s):  
Mineral Exploration ◽  
Porphyry Copper ◽  
Hydrothermal Activity ◽  
White Mica ◽  
Late Triassic ◽  
American Continent ◽  
North American Continent ◽  
Porphyry Cu ◽  
The North ◽  
Molybdenum Deposit

Abstract The Gibraltar Cu-Mo deposit, with a total tonnage of 3.2 million tons (Mt) Cu, is located in the Canadian Cordillera and hosted by the Late Triassic Granite Mountain batholith. The batholith formed through multiple intrusions of tonalitic rocks over a period of ~25 m.y. beginning at 229.2 ± 4.4 Ma in the Quesnel island arc before the accretion of the arc to the North American continent. Late in its evolution, Cu fertile magmas intruded in the center of the batholith, during at least three events from 218.9 ± 3.1 to 205.8 ± 2.1 Ma. The fertile magmas were hotter and more mafic than older barren magmas. They generated magmatic-hydrothermal activity, forming potassic alteration and white mica alteration, and produced Cu mineralization as chalcopyrite-quartz veinlets and disseminated chalcopyrite. Zircon in the Cu-bearing tonalite intrusion (218.9 ± 3.1 Ma) shows high Ce4+/Ce3+ (681 ± 286 [2σ], n =15) compared to those from older barren intrusions (129 ± 56 [2σ], n = 118). Oxidation conditions for parental magmas are calculated using the compositions of zircon and amphibole. The magmas for Cu-bearing intrusions have an average of fayalite-magnetite-quartz buffer (FMQ) +1.7 ± 0.7 (2σ, n = 73), whereas those for older barren intrusions have slightly lower fO2 (avg FMQ +1.3 ± 0.5 [2σ], n = 108), although the values are overlapping for the two. The bulk rocks of Cu-bearing tonalite intrusions in the Granite Mountain batholith have low Sr/Y ratios (<22) independent of the degrees of alteration. The low ratios are also reflected by low Sr/Y in zircon, suggesting that the low Sr/Y ratios of bulk rocks represent those of unaltered rocks. The values are low compared to those associated with many other porphyry Cu deposits globally. The data suggest that igneous rocks elsewhere with low Sr/Y in bulk rocks may have a potential to host economic Cu deposits. Ratios of Ce/Nd and Ce/Ce* (=Ce/((NdN)2SmN)) in zircon are positively correlated with the Ce4+/Ce3+ in zircon from the Granite Mountain batholith. Since the former two ratios can be obtained solely from zircon composition, these ratios from detrital zircon may be useful in evaluating the occurrences of oxidized intrusions in regional mineral exploration.

The Bronze Athena at Byzantium

1947 ◽  
Vol 67 ◽  
pp. 31-33 ◽  
Author(s):  
R. J. H. Jenkins
Keyword(s):  
The West ◽  
The North ◽  
North Side ◽  
Right Hand ◽  
Bronze Statue ◽  
The Common ◽  
Set Up ◽  
The One ◽  
The Right

1. A Bronze statue of Athena, armed, stood in the Forum of Constantine at Constantinople. This fact is witnessed by three well-known passages:(a) Arethas, bishop of Caesareia (ninth to tenth centuries), commenting on a passage of Aristeides, wrote: ‘I believe this (i.e., the Pheidian χαλκῆ Ἀθηνᾶ of Aristeides, Κατὰ τῶν Ἐξορχουμένων, p. 408) is the one set up in the Forum of Constantine, at the porch of the council-chamber, or senate, as they call it now; facing it, on the right-hand side of the porch as you go in, is Thetis, the ⟨mother⟩ of Achilles, with a crown of crabs. The common folk of to-day call the Athena “Earth” and Thetis “Sea”, being misled by the marine monsters on her head.’ (Cf. Kougeas in Laographia IV, 1913, 240, 241.)(b) Cedrenus (eleventh to twelfth centuries), after a note on the senate on the north side of the Forum, continues: ‘On the open square of the Forum stand two statues; to the west, that of Athena of Lindus, wearing a helmet and the monstrous Gorgon's head and snakes entwined about her neck (for so the ancients used to represent her image); and to the east, Amphitrite, with crabs' claws on her temples, which was also brought from Rhodes.’ (Cedrenus, ed. Bonn., I, p. 565; cf. Kougeas, loc. cit. sup.)

A novel route to produce structural polymer foams with a controlled solid skin-porous core structure based on gas diffusion mechanisms

2018 ◽  
Vol 22 (3) ◽  
pp. 822-832 ◽  
Author(s):  
J Pinto ◽  
J Escudero ◽  
E Solórzano ◽  
MA Rodriguez-Perez
Keyword(s):  
Close Contact ◽  
Gas Diffusion ◽  
Solid Polymer ◽  
Polymer Foams ◽  
New Production ◽  
Production Route ◽  
Foaming Process ◽  
Set Up ◽  
The One ◽  
Structural Polymer

A comprehensive study about a new production route of structural polymer foams is presented. This methodology is based on the one hand on a free foaming process induced by a chemical blowing agent inside a closed mold, and on the other hand on the use of a solid polymer able to absorb gas in close contact with the molten foamed polymer, establishing a competitive absorption of the blowing gas between both materials. This competitive absorption of the gas promotes the formation of a solid skin in all the areas in contact with the solid polymer. This phenomenon has been identified in-situ and evaluated in real time using a specific X-ray radioscopy set-up, being possible to relate unequivocally the apparition and thickness of the solid skin with the presence of the solid polymer and with the pressure achieved in the closed mould during the foaming process. The presented production route shows an accurate and independent control of the final foam relative density (even below 0.5) and the thickness of the solid skin, together with an excellent surface quality and a broad applicability, which allows the design and production of structural polymer foams with exceptional features.

MBAH HENDRO KUSUMO BIN SYECH AHMAD MUTAMAKKIN: JEJAK SYIAR ISLAM DI WILAYAH PATI

EMPIRISMA ◽  
2008 ◽  
Vol 27 (2) ◽  
Author(s):  
Fathimatuz Zahra Dan Abdul Azis
Keyword(s):  
Central Region ◽  
Marital Relationship ◽  
Southern Region ◽  
North Coast ◽  
The North ◽  
Trace Back ◽  
Northern Regions ◽  
The One

Pati is a region on the north coast, according to the hypothesis of the researcher, the region is divided into three categories. The northern regions are more religious, the central is more plural, while the southern region is in the middle. In the central region there are many relics of tombs believed to be the those of the Muslim proselytizers in the area of Pati. The one that attracts the researcher is a tomb in the Gambiran area, where there are five local Muslim saints buried, one of them belons to mbah Hendro Kusumo, the son of Syech Ahmad Mutamakkin. This article attempts to trace back the spreading of Islam in Pati based on the existence of thetomb of Mbah Hendro Kusumo. It wants to answer question of whethere the existence of his tomb is due to his studying there or marital relationship, and how it relates to the spreading of Islam.Keywords: Mbah Hendro Kusumo, Traces of Islamic Dakwah, Islam

The Rotterdam Initiative in Reducing Waste Discharges at Source

1991 ◽  
Vol 24 (10) ◽  
pp. 171-177
Author(s):  
T. Vellinga ◽  
J. P. J. Nijssen
Keyword(s):  
Public Relations ◽  
Action Plan ◽  
Detailed Balance ◽  
River Rhine ◽  
The North ◽  
Complementary Role ◽  
Action Programme ◽  
The North Sea ◽  
Set Up

Much of the material dredged from the port of Rotterdam is contaminated to such a degree that it must be placed in specially constructed sites. The aim of Rotterdam is to ensure that the dredged material will once again be clean. This will entail the thorough cleansing of the sources of the contamination of the sediment in the harbours and in the River Rhine. The Rotterdam Rhine Research Project (RRP) is one of the means to achieve this based on: technical research, legal research, public relations and dialogues with dischargers. The programme for five selected heavy metals is almost complete. For many heavy metal discharge points between Rotterdam and Rheinfelden, a specially devised independent load assessment has been carried out four times. Balance studies were used to determine the relative contributions of the point discharges to the total. Currently the results are being used in an attempt to negotiate agreements with a selected number of the major dischargers. At present, more detailed balance studies are being set up and exploratory measurements carried out for organic micropollutants. It may be concluded that the research is progressing successfully and methods and techniques developed seem satisfactory and broadly applicable. The Rhine Action Programme encompasses an international effort to improve the quality of the Rhine water. Although the RRP plays a modest complementary role to the Rhine Action Plan, there is no doubt of the value of this Rotterdam initiative. The mode of work followed in the RRP contains elements that can be of use in combatting the contamination of the North Sea by rivers other than the Rhine.

Preaching and Sermons

2017 ◽  
Author(s):  
Robert H. Ellison
Keyword(s):  
Eighteenth Century ◽  
North Atlantic ◽  
Religious Revival ◽  
Early Nineteenth Century ◽  
Denominational Identity ◽  
The North ◽  
The North Atlantic ◽  
The One ◽  
The Impact

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.

scholarly journals Thinner Sea Ice Contribution to the Remarkable Polynya Formation North of Greenland in August 2018

2021 ◽  
Author(s):  
Xiaoyi Shen ◽  
Chang-Qing Ke ◽  
Bin Cheng ◽  
Wentao Xia ◽  
Mengmeng Li ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Mean Value ◽  
Ocean Model ◽  
North Coast ◽  
Average Value ◽  
The North ◽  
Wind Sea ◽  
The One

AbstractIn August 2018, a remarkable polynya was observed off the north coast of Greenland, a perennial ice zone where thick sea ice cover persists. In order to investigate the formation process of this polynya, satellite observations, a coupled ice-ocean model, ocean profiling data, and atmosphere reanalysis data were applied. We found that the thinnest sea ice cover in August since 1978 (mean value of 1.1 m, compared to the average value of 2.8 m during 1978–2017) and the modest southerly wind caused by a positive North Atlantic Oscillation (mean value of 0.82, compared to the climatological value of −0.02) were responsible for the formation and maintenance of this polynya. The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind. Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.

Excavations at Fishbourne, 1963. Third Interim Report

1964 ◽  
Vol 44 (1) ◽  
pp. 1-8
Keyword(s):  
Interim Report ◽  
The West ◽  
Civic Society ◽  
North West ◽  
The Third ◽  
North East ◽  
The North ◽  
The Future ◽  
Set Up

Early in 1963 much of the land occupied by the Roman building at Fishbourne was purchased by Mr. I. D. Margary, M.A., F.S.A., and was given to the Sussex Archaeological Trust. The Fishbourne Committee of the trust was set up to administer the future of the site. The third season's excavation, carried out at the desire of this committee, was again organized by the Chichester Civic Society.1 About fifty volunteers a day were employed from 24th July to 3rd September. Excavation concentrated upon three main areas; the orchard south of the east wing excavated in 1962, the west end of the north wing, and the west wing. In addition, trial trenches were dug at the north-east and north-west extremities of the building and in the area to the north of the north wing. The work of supervision was carried out by Miss F. Pierce, M.A., Mr. B. Morley, Mr. A. B. Norton, B.A., and Mr. J. P. Wild, B.A. Photography was organized by Mr. D. B. Baker and Mrs. F. A. Cunliffe took charge of the pottery and finds.

Getting the Core: A Neo‐institutionalist Approach to the EMU

1995 ◽  
Vol 30 (3) ◽  
pp. 347-369 ◽  
Author(s):  
Miriam L. Campanella
Keyword(s):  
Financial Markets ◽  
Monetary Union ◽  
Trade Agreement ◽  
Maastricht Treaty ◽  
Convergence Criteria ◽  
The North ◽  
Single European Act ◽  
Effective Role ◽  
Set Up ◽  
New Institutions

THE NEW REGIONALISM, MANIFESTED IN EUROPE BY THE SINGLE European Act and the Maastricht Treaty (1992) and in North America by the signature of the North-American Free Trade Agreement (NAFTA 1993), is centred on strategic policies and new institutions, the aims of which are to achieve a more effective role in global competition. In Europe, the shift is marked by the impending process of monetary union and the creation of its related institutions. The new approach agreed in the Maastricht Treaty sets out four requirements for eligibility to membership of monetary union. Convergence criteria embodying the judgment of financial markets about future inflation, exchange rate and fiscal policy appeared to be the second best choice for governments seeking to institutionalize their commitment to inflation-avoiding policies. The whole mechanism is meant first to provide the region with a credible monetary institution able to win over the financial markets and secondly to set up bulwarks to the inflation-prone pressures of domestic sheltered interests. Thirdly, the aim is to commit member countries, through a so-called targeting exercise (in Keohane's words) to accomplishing the agreed objectives with monetary discipline and macroeconomic adjustment.

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