Isotopic composition of lead in galena and Ni-arsenides of the Midwest deposit, northern Saskatchewan

1984 ◽  
Vol 21 (6) ◽  
pp. 649-656 ◽  
Author(s):  
G. L. Cumming ◽  
D. Krstic ◽  
J. M. Worden ◽  
H. Baadsgaard
Keyword(s):  
Isotopic Composition ◽  
Close Association ◽  
Isotope Ratios ◽  
Pb Isotope ◽  
Macroscopic Scale ◽  
Loss Mechanism ◽  
The Third ◽  
The Past ◽  
Isotopic Compositions ◽  
Basement Rocks

Pb-isotope ratios from galenas and Ni-arsenides of the Midwest deposit indicate that there are three classes of Pb present. The first, with 206Pb/204Pb ratios of about 22.5 and 208Pb/204Pb ratios of about 43.5, occurs only in galenas and is restricted to the basal Athabasca Formation. The second occurs from about 35 m above the unconformity to the deepest samples available to us (60 m into the basement rocks). Characteristically the 206Pb/204Pb ratios are 30–35 and the 208Pb/204Pb ratios are about 50, and this Pb occurs in both galenas and Ni-arsenides. The third class has elevated 206Pb/204Pb ratios ranging up to 350 and occurs within about 10 m of the unconformity in close association with U minerals.A model is developed in which radiogenic additions to galena have occurred during at least two different events. The first added U and Th daughters to "sandstone-type" Pb at 265 ± 50 Ma, and the second added U daughter only to the "basement-type" Pb in the past 50 Ma or less. These events are consistent with Pb loss recorded in the U minerals and indicate that the lead-loss mechanism from these U minerals is catastrophic rather than continuous diffusion.Some trace Pb isotopic compositions in Ni-arsenides suggest to us the occurrence of disequilibrium migration of 238U daughter products, but there is no clear evidence that this occurred on a macroscopic scale in the galena.The model implies that some galena predates the U mineralization, and thus that there is a potential for Pb–(Zn?) mineralization in the basal Athabasca Formation.

Elemental, lead and sulfur isotopic compositions of galena from Kola carbonatites, Russia – implications for melt and mantle evolution

2015 ◽  
Vol 79 (2) ◽  
pp. 219-241 ◽  
Author(s):  
K. Bell ◽  
A. N. Zaitsev ◽  
J. Spratt ◽  
S. Fröjdö ◽  
A. S. Rukhlov
Keyword(s):  
Isotopic Composition ◽  
Mantle Source ◽  
Noble Gas ◽  
Isotope Ratios ◽  
Pb Isotope ◽  
Mantle Evolution ◽  
Isotopic Compositions ◽  
Kola Alkaline Province ◽  
Mantle Sources ◽  
Heterogeneous Mantle

AbstractGalena from four REE-rich (Khibina, Sallanlatvi, Seblyavr, Vuoriyarvi) and REE-poor (Kovdor) carbonatites, as well as hydrothermal veins (Khibina) all from the Devonian Kola Alkaline Province of northwestern Russia was analysed for trace elements and Pb and S isotope compositions. Microprobe analyses show that the only detectable elements in galena are Bi and Ag and these vary from not detectable to 2.23 and not detectable to 0.43 wt.% respectively. Three distinct galena groups can be recognized using Bi and Ag contents, which differ from groupings based on Pb isotope data. The Pb isotope ratios show significant spread with 206Pb/204Pb ratios (16.79 to 18.99), 207Pb/204Pb (15.22 to 15.58) and 208Pb/204Pb ratios (36.75 to 38.62). A near-linear array in a 207Pb/204Pb vs.206Pb/204Pb ratio diagram is consistent with mixing between distinct mantle sources, one of which formed during a major differentiation event in the late Archaean or earlier. The S isotopic composition (δ34S) of galena from carbonatites is significantly lighter (–6.7 to –10.3% Canyon Diablo Troilite (CDT) from REE-rich Khibina, Seblyavr and Vuoriyarvi carbonatites, and – 3.2% CDT from REE-poor Kovdor carbonatites) than the mantle value of 0%. Although there is no correlation between S and any of the Pb isotope ratios, Bi and Ag abundances correlate negatively with δ34S values. The variations in the isotopic composition of Pb are attributed to partial melting of an isotopically heterogeneous mantle source, while those of δ34S (together with Bi and Ag abundances) are considered to be process driven. Although variation in Pb isotope values between complexes might reflect different degrees of interaction between carbonatitic melts and continental crust or metasomatized lithosphere, the published noble gas and C, O, Sr, Nd and Hf isotopic data suggest that the variable Pb isotope ratios are best attributed to isotopic differences preserved within a sub-lithospheric mantle source. Different Pb isotopic compositions of galena from the same complex are consistent with a model of magma replenishment by carbonatitic melts/fluids each marked by quite different Pb isotopic compositions.

scholarly journals Constraining N<sub>2</sub>O emissions since 1940 using firn air isotope measurements in both hemispheres

2017 ◽  
Vol 17 (7) ◽  
pp. 4539-4564 ◽  
Author(s):  
Markella Prokopiou ◽  
Patricia Martinerie ◽  
Célia J. Sapart ◽  
Emmanuel Witrant ◽  
Guillaume Monteil ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Mole Fraction ◽  
Radiative Forcing ◽  
Temporal Evolution ◽  
Atmospheric Model ◽  
Site Preference ◽  
Ocean Water ◽  
The Third ◽  
The Past ◽  
Global Mean

Abstract. N2O is currently the third most important anthropogenic greenhouse gas in terms of radiative forcing and its atmospheric mole fraction is rising steadily. To quantify the growth rate and its causes over the past decades, we performed a multi-site reconstruction of the atmospheric N2O mole fraction and isotopic composition using new and previously published firn air data collected from Greenland and Antarctica in combination with a firn diffusion and densification model. The multi-site reconstruction showed that while the global mean N2O mole fraction increased from (290 ± 1) nmol mol−1 in 1940 to (322 ± 1) nmol mol−1 in 2008, the isotopic composition of atmospheric N2O decreased by (−2.2 ± 0.2) ‰ for δ15Nav, (−1.0 ± 0.3) ‰ for δ18O, (−1.3 ± 0.6) ‰ for δ15Nα, and (−2.8 ± 0.6) ‰ for δ15Nβ over the same period. The detailed temporal evolution of the mole fraction and isotopic composition derived from the firn air model was then used in a two-box atmospheric model (comprising a stratospheric box and a tropospheric box) to infer changes in the isotopic source signature over time. The precise value of the source strength depends on the choice of the N2O lifetime, which we choose to fix at 123 years. The average isotopic composition over the investigated period is δ15Nav =  (−7.6 ± 0.8) ‰ (vs. air-N2), δ18O  =  (32.2 ± 0.2) ‰ (vs. Vienna Standard Mean Ocean Water – VSMOW) for δ18O, δ15Nα =  (−3.0 ± 1.9) ‰ and δ15Nβ =  (−11.7 ± 2.3) ‰. δ15Nav, and δ15Nβ show some temporal variability, while for the other signatures the error bars of the reconstruction are too large to retrieve reliable temporal changes. Possible processes that may explain trends in 15N are discussed. The 15N site preference ( = δ15Nα − δ15Nβ) provides evidence of a shift in emissions from denitrification to nitrification, although the uncertainty envelopes are large.

Deposition and migration of atmospheric Pb in soils from a forested silicate catchment today and in the past (Strengbach case): Evidence from 210Pb activities and Pb isotope ratios

2011 ◽  
Vol 289 (1-2) ◽  
pp. 140-153 ◽  
Author(s):  
P. Stille ◽  
L. Pourcelot ◽  
M. Granet ◽  
M.-C. Pierret ◽  
F. Guéguen ◽  
...  
Keyword(s):  
Isotope Ratios ◽  
Pb Isotope ◽  
The Past ◽  
And Migration

Al-Rasm al-ʿUthmānī: Towards Correct Pronunciation and the Preclusion of Ambiguity

2011 ◽  
Vol 13 (2) ◽  
pp. 201-171
Author(s):  
Nāṣir Al-Dīn Abū Khaḍīr
Keyword(s):  
Specific Pattern ◽  
Writing Style ◽  
The Third ◽  
The Past ◽  
Different Ages ◽  
Correct Pronunciation ◽  
The One ◽  
The Mind

The ʿUthmānic way of writing (al-rasm al-ʿUthmānī) is a science that specialises in the writing of Qur'anic words in accordance with a specific ‘pattern’. It follows the writing style of the Companions at the time of the third caliph, ʿUthmān b. ʿAffān, and was attributed to ʿUthmān on the basis that he was the one who ordered the collection and copying of the Qur'an into the actual muṣḥaf. This article aims to expound on the two fundamental functions of al-rasm al-ʿUthmānī: that of paying regard to the ‘correct’ pronunciation of the words in the muṣḥaf, and the pursuit of the preclusion of ambiguity which may arise in the mind of the reader and his auditor. There is a further practical aim for this study: to show the connection between modern orthography and the ʿUthmānic rasm in order that we, nowadays, are thereby able to overcome the problems faced by calligraphers and writers of the past in their different ages and cultures.

Lot's Offer of his Daughters to his People in the Torah and the Qur'an: A Comparative Study in Two Parts (Part One)

2016 ◽  
Vol 18 (3) ◽  
pp. 161-224
Author(s):  
ʿĀʾiḍ B. Sad Al-Dawsarī
Keyword(s):  
Comparative Study ◽  
Comparative Studies ◽  
The Third ◽  
The Past ◽  
The Status ◽  
Moral Problems ◽  
Moral Dimensions ◽  
Similarities And Differences

The story of Lot is one of many shared by the Qur'an and the Torah, and Lot's offer of his two daughters to his people is presented in a similar way in the two books. This article compares the status of Lot in the Qur'an and Torah, and explores the moral dimensions of his character, and what scholars of the two religions make of this story. The significance of the episodes in which Lot offers his daughters to his people lies in the similarities and differences of the accounts given in the two books and the fact that, in both the past and the present, this story has presented moral problems and criticism has been leveled at Lot. Context is crucial in understanding this story, and exploration of the ways in which Lot and his people are presented is also useful in terms of comparative studies of the two scriptures. This article is divided into three sections: the first explores the depiction of Lot in the two texts, the second explores his moral limitations, and the third discusses the interpretations of various exegetes and scholars of the two books. Although there are similarities between the Qur'anic and Talmudic accounts of this episode, it is read differently by scholars from the two religions because of the different contexts of the respective accounts.

Negotiating Tripartite Philosophy (Strategy–tactics–technique)

2019 ◽  
Vol 1 (1) ◽  
pp. 53
Author(s):  
Hazem Hamad Mousa Al Janabi
Keyword(s):  
Bottom Line ◽  
Negotiation Strategy ◽  
The Third ◽  
The Past

Tripartite Negotiating philosophy: (strategy - tactics - technique) At the beginning , the research consists of four sections as follows: The first axis titled: "what negotiation", and the second axis: "philosophy of negotiation," The third axis titled: "negotiation strategy". Down to the fourth axis which included titled: "negotiating tactic", Sajama with the past and as a supplement came fifth axis titled: "negotiating technique", to be the bottom line in the form of a set of conclusions. Negotiation consists of a base triple hierarchical strategy - tactics - technique. The philosophy of negotiating interactive basis of rationality. Negotiable three parties are the position and the case and the parties involved. Is the process of negotiating strategic recruitment capacity and capabilities to achieve the desired goal of the crisis prematurely. Negotiating tactic is the process of hiring capacity and capabilities to achieve the desired goal at the negotiating table. •The technique is the process of negotiating employment capacity and capabilities to achieve the desired goal at the negotiating table to contain thesudden things check response and renewed flexibility.

Same Address, Different Doors: Post-Heritage Deconstruction of the Heritage Household in Upstairs Downstairs in the 1970s and 2010s

2020 ◽  
Author(s):  
William Abbiss
Keyword(s):  
Final Section ◽  
Social Structures ◽  
The Third ◽  
The Past ◽  
War Narrative ◽  
Critical History ◽  
The Social ◽  
Fourth Series ◽  
History Of ◽  
Multiple Episodes

This article offers a ‘post-heritage’ reading of both iterations of Upstairs Downstairs: the LondonWeekend Television (LWT) series (1971–5) and its shortlived BBC revival (2010–12). Identifying elements of subversion and subjectivity allows scholarship on the LWT series to be reassessed, recognising occasions where it challenges rather than supports the social structures of the depicted Edwardian past. The BBC series also incorporates the post-heritage element of self-consciousness, acknowledging the parallel between its narrative and the production’s attempts to recreate the success of its 1970s predecessor. The article’s first section assesses the critical history of the LWT series, identifying areas that are open to further study or revised readings. The second section analyses the serialised war narrative of the fourth series of LWT’s Upstairs, Downstairs (1974), revealing its exploration of female identity across multiple episodes and challenging the notion that the series became more male and upstairs dominated as it progressed. The third section considers the BBC series’ revised concept, identifying the shifts in its main characters’ positions in society that allow the series’ narrative to question the past it evokes. This will be briefly contrasted with the heritage stability of Downton Abbey (ITV, 2010–15). The final section considers the household of 165 Eaton Place’s function as a studio space, which the BBC series self-consciously adopts in order to evoke the aesthetics of prior period dramas. The article concludes by suggesting that the barriers to recreating the past established in the BBC series’ narrative also contributed to its failure to match the success of its earlier iteration.

Same Address, Different Doors: Post-Heritage Deconstruction of the Heritage Household in Upstairs Downstairs in the 1970s and 2010s

2020 ◽  
Author(s):  
William Abbiss
Keyword(s):  
Final Section ◽  
Social Structures ◽  
The Third ◽  
The Past ◽  
War Narrative ◽  
Critical History ◽  
The Social ◽  
Fourth Series ◽  
History Of ◽  
Multiple Episodes

This article offers a ‘post-heritage’ reading of both iterations of Upstairs Downstairs: the LondonWeekend Television (LWT) series (1971–5) and its shortlived BBC revival (2010–12). Identifying elements of subversion and subjectivity allows scholarship on the LWT series to be reassessed, recognising occasions where it challenges rather than supports the social structures of the depicted Edwardian past. The BBC series also incorporates the post-heritage element of self-consciousness, acknowledging the parallel between its narrative and the production’s attempts to recreate the success of its 1970s predecessor. The article’s first section assesses the critical history of the LWT series, identifying areas that are open to further study or revised readings. The second section analyses the serialised war narrative of the fourth series of LWT’s Upstairs, Downstairs (1974), revealing its exploration of female identity across multiple episodes and challenging the notion that the series became more male and upstairs dominated as it progressed. The third section considers the BBC series’ revised concept, identifying the shifts in its main characters’ positions in society that allow the series’ narrative to question the past it evokes. This will be briefly contrasted with the heritage stability of Downton Abbey (ITV, 2010–15). The final section considers the household of 165 Eaton Place’s function as a studio space, which the BBC series self-consciously adopts in order to evoke the aesthetics of prior period dramas. The article concludes by suggesting that the barriers to recreating the past established in the BBC series’ narrative also contributed to its failure to match the success of its earlier iteration.

Holy Land, Whose Land

2003 ◽  
Vol 20 (3-4) ◽  
pp. 208-210
Author(s):  
Zaineb Lstrabadi
Keyword(s):  
Holy Land ◽  
The Third ◽  
The Past ◽  
Third Millennium ◽  
Arab Israeli Conflict

Dorothy Drummond's book was born at the dawn of the third millennium,when the author was in Jerusalem. She had taken notes throughout hertravels in the Holy Land, which she defines not only as the land of historicPalestine, but also the lands of present-day Lebanon, Jordan, Syria, Iraq,and Egypt (i.e., where the Patriarchs, Prophets, and the Holy Familyroamed). Rather than write a travelogue, she decided to write a book aboutthe Arab-Israeli conflict while interspersing her personal comments (initalics) about her journeys. Her intent is not to "answer the question posedin the title of this book. Rather, by shedding light on dark corners, itattempts to bring understanding," as she explains in the prologue.The book is divided into three parts: a discussion of the IsraeliPalestinianconflict in the present, a discussion of the roots of the conflicttraveling 4,000 years into the past, and a brief discussion of how negotiationis the only way to resolve the conflict. There are maps and pho tographsthroughout the book, as well as a 40-page glossary of the HolyLand's people and places. Drummond has written the work in the presenttense, because of the immediacy of all that has happened in the MiddleEast, but the discussion ultimately centers on the area between theMediterranean Sea and the Jordan River.Her book promises to be a good, balanced account written in a wonwonderfullyaccessible style. However, early on it runs into problems. Forexample, when she talks about the 1956 Israeli attack on Egypt, she fails ...

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