PALAEOMAGNETISM OF DIABASE DYKES OF THE CANADIAN SHIELD

1965 ◽  
Vol 2 (4) ◽  
pp. 278-298 ◽  
Author(s):  
W. F. Fahrig ◽  
E. H. Gaucher ◽  
A. Larochelle
Keyword(s):  
Remanent Magnetization ◽  
Lake Superior ◽  
Canadian Shield ◽  
Igneous Rocks ◽  
Palaeomagnetic Data ◽  
The World ◽  
Oriented Samples ◽  
The Mean ◽  
The Individual ◽  
Dyke Swarms

Some areas of the Canadian Shield are profusely intruded by swarms of subparallel basaltic dykes. These typically have a diabasic texture and formerly were considered to be strictly the intrusive equivalents of tholeiitic flood basalt.About 650 oriented samples were collected from about 25 dyke swarms and preliminary palaeomagnetic data from six of them are presented here. The Mackenzie swarm has a K–Ar age of 1 295 million years, occurs throughout the western Canadian Shield, and is the most extensive swarm of basic dykes known anywhere in the world. The other swarms are the Molson dykes (1 445 m.y.) in northeastern Manitoba, the Marathon dykes (1 810 m.y.) just north of Lake Superior, the Sudbury dykes (1 285 m.y.) of southeastern Ontario, the Matachewan dykes (2 485 m.y.) of western Quebec and northeastern Ontario, and the Abitibi dykes (1 230 m.y.), which occur from Sault Ste. Marie, Ontario, to Lake Mistassini, Quebec.The palaeomagnetic virtual pole positions of six swarms were derived from the mean of their measured remanent magnetization directions. These directions of magnetization were determined from the samples after they were magnetically washed in an a-c. field of 80 or 130 oersteds. The reasons for the dispersion within the individual swarms are discussed. The pole positions of the Sudbury and Mackenzie dykes are almost identical and the two swarms are the same age within the limits of analytical uncertainty. However, basalt of the Sudbury swarm is alkalic and more undersaturated than basalt of the Mackenzie dykes.No evidence was found to contradict the usual assumption that unaltered basic igneous rocks of this type acquire and generally retain a stable magnetization which was parallel with the earth's magnetic field at the time of the dyke intrusion.

scholarly journals Internal consistency of the Regional Brewer Calibration Centre for Europe triad during the period 2005–2016

2018 ◽  
Vol 11 (7) ◽  
pp. 4059-4072 ◽  
Author(s):  
Sergio Fabián León-Luis ◽  
Alberto Redondas ◽  
Virgilio Carreño ◽  
Javier López-Solano ◽  
Alberto Berjón ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Data Sets ◽  
Individual Values ◽  
Relative Standard ◽  
The World ◽  
The Mean ◽  
The Individual ◽  
Ozone Column

Abstract. Total ozone column measurements can be made using Brewer spectrophotometers, which are calibrated periodically in intercomparison campaigns with respect to a reference instrument. In 2003, the Regional Brewer Calibration Centre for Europe (RBCC-E) was established at the Izaña Atmospheric Research Center (Canary Islands, Spain), and since 2011 the RBCC-E has transferred its calibration based on the Langley method using travelling standard(s) that are wholly and independently calibrated at Izaña. This work is focused on reporting the consistency of the measurements of the RBCC-E triad (Brewer instruments #157, #183 and #185) made at the Izaña Atmospheric Observatory during the period 2005–2016. In order to study the long-term precision of the RBCC-E triad, it must be taken into account that each Brewer takes a large number of measurements every day and, hence, it becomes necessary to calculate a representative value of all of them. This value was calculated from two different methods previously used to study the long-term behaviour of the world reference triad (Toronto triad) and Arosa triad. Applying their procedures to the data from the RBCC-E triad allows the comparison of the three instruments. In daily averages, applying the procedure used for the world reference triad, the RBCC-E triad presents a relative standard deviation equal to σ = 0.41 %, which is calculated as the mean of the individual values for each Brewer (σ157 = 0.362 %, σ183 = 0.453 % and σ185 = 0.428 %). Alternatively, using the procedure used to analyse the Arosa triad, the RBCC-E presents a relative standard deviation of about σ = 0.5 %. In monthly averages, the method used for the data from the world reference triad gives a relative standard deviation mean equal to σ = 0.3 % (σ157 = 0.33 %, σ183 = 0.34 % and σ185 = 0.23 %). However, the procedure of the Arosa triad gives monthly values of σ = 0.5 %. In this work, two ozone data sets are analysed: the first includes all the ozone measurements available, while the second only includes the simultaneous measurements of all three instruments. Furthermore, this paper also describes the Langley method used to determine the extraterrestrial constant (ETC) for the RBCC-E triad, the necessary first step toward accurate ozone calculation. Finally, the short-term or intraday consistency is also studied to identify the effect of the solar zenith angle on the precision of the RBCC-E triad.

scholarly journals Palaeomagnetism of the Mahatta Humaid Group (Cambrian – Early Ordovician, Oman), including a re-interpretation of previous Neoproterozoic palaeomagnetic data

GeoArabia ◽  
2009 ◽  
Vol 14 (2) ◽  
pp. 71-96
Author(s):  
Haroldo Vizán ◽  
Peter Turner ◽  
John A. Millson ◽  
Rob A. Ixer
Keyword(s):  
Remanent Magnetization ◽  
Sedimentary Basins ◽  
Vertical Axis ◽  
Petrographic Analysis ◽  
Polar Wander ◽  
Magnetic Carriers ◽  
Palaeomagnetic Data ◽  
Primary Origin ◽  
The Mean ◽  
Early Palaeozoic

ABSTRACT We carried out a palaeomagnetic study in the Al-Huqf region (Sultanate of Oman) on rocks that belong to different units of the Cambrian – Ordovician Mahatta Humaid Group. Thirty-nine samples were systematically collected from a succession ca. 520–495 Ma old. Seventeen samples showed characteristic remanent magnetization components with two antipodal polarities carried by hematite. Evidence suggests that these components have a primary origin. A detailed petrographic analysis revealed syntaxial overgrowths parallel to the easy plane of magnetization of the magnetic carriers that has probably enhanced and reinforced the primary magnetization. A palaeopole computed with the mean direction of the 17 characteristic remanent magnetization components was considered alongside previously published Neoproterozoic – early Palaeozoic palaeomagnetic data, which we placed in an updated chronostratigraphic framework for the Neoproterozoic – Cambrian Huqf Supergroup. Two interpretations were considered: (1) Oman was detached from the Arabian-Nubian craton until ca. 660 Ma, and it became attached (or was nearby) to it by ca. 630 Ma. In this interpretation, an apparent polar wander (APW) path of Arabia is proposed between ca. 630 and 500 Ma. The palaeomagnetic directions of Mirbat obtained by Killner et al. (2005) in rocks 720–660 Ma old are therefore assumed as primary, and taking into account that Oman was an independent block of the Arabian-Nubian craton, the corresponding palaeopole is not considered in the proposed segment of the Arabian APW path. (2) The Neoproterozoic data belong to two different tectonic blocks within the Arabian-Nubian craton and were involved in left-lateral, strike-slip movements along NW-trending faults. One block included the localities of Al Jabal al-Akhdar and Al-Huqf and may have rotated counter-clockwise c. 45° about a vertical axis between ca. 600 and 500 Ma. The other block included the locality of Mirbat and rotated counter-clockwise c. 25° about a vertical axis between ca. 600 and 550 Ma. These suggested block rotations may have played a role in generating the underlying fabrics for some of the sedimentary basins in Oman. In the second model, the rocks sampled by Killner et al. (2005) in Mirbat were re-magnetized during the intrusion of dike swarms at ca. 615–600 Ma.

Geological constraints on the origin of the mantle root beneath the Canadian shield

1990 ◽  
Vol 331 (1620) ◽  
pp. 523-532 ◽  
Keyword(s):  
Seismic Anisotropy ◽  
Sedimentary Cover ◽  
Oceanic Lithosphere ◽  
Systematic Difference ◽  
Canadian Shield ◽  
Cratonic Mantle ◽  
Crustal Reworking ◽  
The Mean ◽  
Geological Constraints ◽  
Dyke Swarms

Cratonic North America is composed of a cluster of Archaean microcontinents centred on the Canadian shield, and juvenile Proterozoic crust that lies mainly buried beneath the sedimentary cover of the western and southern interior platforms. The shield is underlain by an anomalous low-temperature mantle root that is absent beneath the platform. As there appears to be no systematic difference in crustal thickness or density between the shield and the platform, the long-lived arching of the shield implies an intrinsic buoyancy imparted by the mantle root that more than offsets its colder temperature. Isotopic and seismic anisotropy data indicate an Archaean age for the mantle root, close to the time of formation of the overlying crust. The preferential development of the mantle root beneath Archaean crust is consistent with an origin by imbrication of partly subducted slabs of highly depleted oceanic lithosphere, assuming that buoyant subduction was more common in the Archaean. Formation of the mantle root was not dependent on collisional orogenesis, as has been suggested, but the Archaean cratonic mantle was sufficiently buoyant and refractory to survive later tectonic thickening. The mantle root persists beneath Archaean crust that was transected by mafic dyke swarms and subjected to short-lived episodes of post-orogenic crustal melting, but the root is reduced at mantle plume initiation sites. The partitioning of Archaean and Proterozoic crust between the shield and the platform, respectively, causes the shield to misrepresent Precambrian crust as a whole. Studies of the shield falsely conclude that a high percentage of Precambrian crust formed in the Archaean, and that the Proterozoic was characterized by epicontinental volcanism and sedimentation, and crustal ‘reworking’. Furthermore, the isotopic ratios of detritus eroded from the craton may tend to overestimate the mean age of continental crust.

scholarly journals Is “Unconsummated Marriage” Still an Appropriate Term? A Snapshot of Reality

2016 ◽  
Vol 9 (1) ◽  
pp. 64-64
Author(s):  
M. Silvaggi ◽  
◽  
P. M. Michetti ◽  
A. Fabrizi ◽  
R. Rossi ◽  
...  
Keyword(s):  
Causal Attribution ◽  
Middle Eastern ◽  
Performance Anxiety ◽  
The Other ◽  
Sexual Dysfunctions ◽  
Social Variables ◽  
The World ◽  
The Mean ◽  
The Individual ◽  
Mean Time

Objective: In the middle eastern (MES) and western (WS) societies, sexuality follows different patterns in terms of meaning and rules. Moreover the evolution of societies all around the world created new contexts and kinds of relationship. This could hamper a correct taxonomy of such sexual dysfunctions where social variables are crucial. The aim of the present work is to collect and review data on Unconsummated Marriage (UCM) all around the world, to understand if in different societies it refers to the same situation. Design and Method: A review of published literature on UCM from different areas of the world was conducted. Results: Substantial difference emerged from MES to WS. In MES, sexuality is allowed only in marriage, while in WS sexuality and relationship are not strongly linked. This could suggest that the term “marriage” is unable to cover the phenomenon in such different countries. Moreover, the mean time before the consultation, causal attribution and prevalence are very different in such societies. Conclusions: We found that the term “Honeymoon impotence” could better describe male, female or both difficulties related to ignorance about sexuality or state/performance anxiety, typical in MES. On the other hand in WS over the individual category of sexual dysfunctions, we suggest a new term as “Unconsummated relationship”, where individual difficulties are involved creating a couple’s dysfunction.

Paleomagnetism of the Precambrian Martin Formation, Saskatchewan

1973 ◽  
Vol 10 (10) ◽  
pp. 1485-1493 ◽  
Author(s):  
M. E. Evans ◽  
D. K. Bingham
Keyword(s):  
North America ◽  
Strong Evidence ◽  
Sedimentary Basins ◽  
Canadian Shield ◽  
Igneous Rocks ◽  
Paleomagnetic Pole ◽  
Oriented Samples ◽  
The Subject

Oriented samples of the Martin Formation were collected from 23 sites, both sediments and igneous rocks being represented. Detailed laboratory treatment yields an overall mean direction corresponding to a paleomagnetic pole at 9 °S, 72 °W (dp = 6.3°, dm = 11.5°). Strong evidence for the primary nature of the magnetization involved is provided by a positive fold test. The paleomagnetic pole obtained provides further evidence for a major eastward loop in the polar wandering path for North America during late Aphebian – early Helikian times. The exact age of Martin Formation deposition is the subject of debate, but extreme limits given by various authors are 1930 to 1490 m.y. However, the paleomagnetic results themselves somewhat restrict this range, and are of use in setting up a regional chronology, since they enable stratigraphic correlations between isolated sedimentary basins of the Canadian Shield to be made.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Perbedaan Pengetahuan Siswa Tentang Penyakit Hepatitis A Sebelum Dan Sesudah Penyuluhan Di MTsN 02 Bondowoso Tahun 2015

2017 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Putri Megasari
Keyword(s):  
Hepatitis A ◽  
Hepatitis Virus ◽  
Sampling Technique ◽  
Mean Value ◽  
Test Design ◽  
The World ◽  
Before And After ◽  
Post Test ◽  
The Mean ◽  
Paired T Test

Hepatitis has become a health problem in the world. The hepatitis virus infected many people. According to the teacher of MTsN 02 Bondowoso more than 20 students have hepatitis A viral infection. The purpose of this research was to know the differences of students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study used pre-experimental (pre-post test design). This study used stratified random sampling technique, 127 students from 270 sample involved this research,and 143 students was excluded. We used questionnaires to collect data. The results showed that the mean value of the students 'knowledge about hepatitis A before counseling in MTsN 02 Bondowoso 2015 was 83.96 with the lowest value of 37.5 and the highest value was 100. The mean value of the students' knowledge about hepatitis A after counseling in MTsN 02 Bondowoso 2015 was 93.21 with the lowest value waf 62.5 and the highest value was 100. Paired t test showed that t (-9.07) > t table (1.98), the null hypothesis (H0) was rejected. There was a difference between students' knowledge about hepatitis A before and after counseling in MTsN 02 Bondowoso 2015. This study showed that routine counseling by healthcare provider was important to prevent hepatitis A infection.; Keywords: counseling, knowledge of students, hepatitis

New walls to keep the bad out: populism and the totalitarian psyche

2019 ◽  
Vol 1 (2) ◽  
pp. 120-130
Author(s):  
Coline Covington
Keyword(s):  
Cold War ◽  
Balance Of Power ◽  
Berlin Wall ◽  
Group Solidarity ◽  
Freedom Of Movement ◽  
Psychological Understanding ◽  
Psychic Development ◽  
The World ◽  
The Individual ◽  
The Cold War

The Berlin Wall came down on 9 November 1989 and marked the end of the Cold War. As old antagonisms thawed a new landscape emerged of unification and tolerance. Censorship was no longer the principal means of ensuring group solidarity. The crumbling bricks brought not only freedom of movement but freedom of thought. Now, nearly thirty years later, globalisation has created a new balance of power, disrupting borders and economies across the world. The groups that thought they were in power no longer have much of a say and are anxious about their future. As protest grows, we are beginning to see that the old antagonisms have not disappeared but are, in fact, resurfacing. This article will start by looking at the dissembling of a marriage in which the wall that had peacefully maintained coexistence disintegrates and leads to a psychic development that uncannily mirrors that of populism today. The individual vignette leads to a broader psychological understanding of the totalitarian dynamic that underlies populism and threatens once again to imprison us within its walls.

Virginia Woolf and Being-in-the-world

2017 ◽  
Author(s):  
Emma Simone
Keyword(s):  
Virginia Woolf ◽  
Historical Context ◽  
The Political ◽  
Cartesian Dualism ◽  
Self And Other ◽  
The World ◽  
Binary Oppositions ◽  
The Individual ◽  
The Relationship ◽  
Existential Perspective

Virginia Woolf and Being-in-the-world: A Heideggerian Study explores Woolf’s treatment of the relationship between self and world from a phenomenological-existential perspective. This study presents a timely and compelling interpretation of Virginia Woolf’s textual treatment of the relationship between self and world from the perspective of the philosophy of Martin Heidegger. Drawing on Woolf’s novels, essays, reviews, letters, diary entries, short stories, and memoirs, the book explores the political and the ontological, as the individual’s connection to the world comes to be defined by an involvement and engagement that is always already situated within a particular physical, societal, and historical context. Emma Simone argues that at the heart of what it means to be an individual making his or her way in the world, the perspectives of Woolf and Heidegger are founded upon certain shared concerns, including the sustained critique of Cartesian dualism, particularly the resultant binary oppositions of subject and object, and self and Other; the understanding that the individual is a temporal being; an emphasis upon intersubjective relations insofar as Being-in-the-world is defined by Being-with-Others; and a consistent emphasis upon average everydayness as both determinative and representative of the individual’s relationship to and with the world.

“Utopia First!” A Machiavellian Conception of Solidarity in More's Utopia

Moreana ◽  
2018 ◽  
Vol 55 (Number 209) (1) ◽  
pp. 79-93
Author(s):  
Marie-Claire Phélippeau
Keyword(s):  
At Risk ◽  
Human Beings ◽  
Farm Work ◽  
The World ◽  
Social Difficulties ◽  
The Republic ◽  
The Individual ◽  
Democratic Elections ◽  
Communal Organization

This paper shows how solidarity is one of the founding principles in Thomas More's Utopia (1516). In the fictional republic of Utopia described in Book II, solidarity has a political and a moral function. The principle is at the center of the communal organization of Utopian society, exemplified in a number of practices such as the sharing of farm work, the management of surplus crops, or the democratic elections of the governor and the priests. Not only does solidarity benefit the individual Utopian, but it is a prerequisite to ensure the prosperity of the island of Utopia and its moral preeminence over its neighboring countries. However, a limit to this principle is drawn when the republic of Utopia faces specific social difficulties, and also deals with the rest of the world. In order for the principle of solidarity to function perfectly, it is necessary to apply it exclusively within the island or the republic would be at risk. War is not out of the question then, and compassion does not apply to all human beings. This conception of solidarity, summed up as “Utopia first!,” could be dubbed a Machiavellian strategy, devised to ensure the durability of the republic. We will show how some of the recommendations of Realpolitik made by Machiavelli in The Prince (1532) correspond to the Utopian policy enforced to protect their commonwealth.

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