scholarly journals Tectonics-mineralisation relationships within weak continental lithospheres: a new structural framework for Precambrian cratons

2018 ◽  
Vol 189 (3) ◽  
pp. 14 ◽  
Author(s):  
Denis Gapais
Keyword(s):  
Mineral Resources ◽  
Structural Data ◽  
The Other ◽  
Suitable Model ◽  
Structural Patterns ◽  
Structural Framework ◽  
Analogue Modelling ◽  
Other Hand ◽  
Deformation Patterns ◽  
Mining Exploration

Many Archaean and Paleoproterozoic cratons show deformation patterns that differ from those observed in modern orogens. On the other hand, they constitute an important part of present-day emerged continents and contain a large part of continental mineral resources known to date. On the basis of a summary of structural data from some typical field examples and of results of analogue modelling, we emphasize that pop-down tectonics marked by vertical burial of supracrustals within an underlying hot and weak crust may be the most suitable model to account for deformation patterns of many ancient deformation zones. An overview of relationships between structural patterns and mineralisation in several ancient deformation zones further emphasizes that pop-down tectonics provides a very promising structural framework for mining exploration in Precambrian cratons.

Ideophones’ challenges for typological linguistics

2014 ◽  
Vol 5 (3) ◽  
pp. 355-383 ◽  
Author(s):  
Janis B. Nuckolls
Keyword(s):  
The Other ◽  
Special Focus ◽  
Motion Verbs ◽  
Structural Patterns ◽  
Action Event ◽  
Other Hand ◽  
Verbs Of Motion ◽  
Amazonian Ecuador ◽  
The One ◽  
Made In

Typological studies of motion verbs have struggled to conceptualize a framework that would adequately account for languages which make use of ideophoness for expressing manner of motion. This paper examines ideophones in the Pastaza Quichua dialect of Amazonian Ecuador, with a special focus on the structural patterns observable in two categories of Quichua verbs of motion: verbs of motion by limited translocation and verbs of motion by nonlimited translocation. These two types of verbs and their ideophones manifest 5 major patterns of verb/ideophone interaction, which may be schematized with a gradient scale of possibilities. On the one hand, verbs and their ideophones may come together and coalesce into a unity of meaning, a meaning that is, in fact, lexicalized in one verb form by other languages. On the other hand, verbs and their ideophones may be more inclined toward a ‘separatist semantics’, in which each entity expresses a conceptually distinctive action, event, or process. These patterns problematize several assumptions made in typological studies.

X-ray structures and luminescence properties of Co(II) and Co(III) complexes of cofacial diporphyrins

2003 ◽  
Vol 07 (07) ◽  
pp. 474-483 ◽  
Author(s):  
Frédéric Bolze ◽  
Marc Drouin ◽  
Pierre D. Harvey ◽  
Claude P. Gros ◽  
Enrique Espinosa ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Structural Data ◽  
Previous Literature ◽  
The Other ◽  
Luminescence Properties ◽  
X Ray ◽  
Face To Face ◽  
Other Hand

The crystal structures of two face-to-face diporphyrin compounds based upon the DPA ligand (1,8-bis(5-(2,8,13,17-tetraethyl-3,7,12,18-tetramethyl-porphyrinyl))anthracene), i.e. H 4( DPA ) and ( DPA ) Co 2 are reported. The structural data are compared to that of other bimetallic DPA systems, and diporphyrinic Co complexes. In addition, the luminescence properties of ( OEP ) Co ( OEP = 2,3,7,8,12,13,17,18-octaethylporphyrin), H 2( DPA ) Co , H 2( DPA )( CoIm ) O 2, ( DPA ) Co 2, ( DPA )( CoIm )2 O 2 are reported, where Im is 1-t-butyl-5-phenyl imidazole. Contrary to previous literature reports, the Co (II) species are found to be weakly luminescent, where fluorescence is detected for both the mono- and diporphyrinic systems, and is assigned to emissions arising from the lowest 1 Q (ππ*) states, while phosphorescence is detected at 77 K only for the monoporphyrin species, ( OEP ) Co . On the other hand, the Co (III) complexes are not luminescent.

Brittle Deformation and Neotectonics of the Serra da Cantareira Ridge, Pico do Jaraguá Hill, and Perus Region – Southeastern Brazil

2020 ◽  
Author(s):  
Marcos Pinheiro ◽  
Paola Cianfarra
Keyword(s):  
Structural Data ◽  
The Other ◽  
Tectonic Activity ◽  
Southeastern Brazil ◽  
Brittle Deformation ◽  
Stress Regime ◽  
Tectonic Regime ◽  
Neotectonic Activity ◽  
Other Hand

<p>Classical geomorphological and geological researches state that the Brazilian landscapes are mostly influenced by the old tectonics (Pre Cenozoic), considering that such region is currently far away from the South America plate border, where seismic activity is higher. On the other hand, recent studies are pointing out present-day tectonic activity in the southeast Brazil thus revealing that Neotectonics, the tectonic regime acting since Neogene, has an important role on the evolution of the Brazilian landforms, including the Continental Rift of Southeastern Brazil, which comprises a set of 900 km length of ENE-WSW tectonic lines and tertiary basins. However, information about Neotectonic activity in the nearby zones of the rift are still missing, such as in the Serra da Cantareira Ridge, Pico do Jaraguá Hill and Perus region, both of them characterized by outcrops of Pre Cambrian igneous and metamorphic rocks. In this way, the objective of this research is to study the brittle deformation of these areas in order to identify possible traces of Neotectonics. This young tectonic was explored through lineament domains, which were automatically detected by SID software and statistically analyzed through Daisy 3 software. In the field, 712 structural data were surveyed in 51 outcrops and cumulated into databases of the Daisy 3 software, in order to identify the main fault azimuthal trends, fault kinematics, and compute the paleostresses. The lineament analysis show the presence of a principal E-W lineament domain, coincident and possibly related to an old (Neoproterozoic), shear zone probably reactivated in the current tectonic regime.  The field data indicate the predominance of NW-SE, E-W, and NE-SW strike-slip faults, compatible with the left and right-lateral kinematics of the E-W shear corridor. The computed paleostresses are similar to the Neotectonic stress regime identified in the surrounding areas by other researches: NE-SW compression and NW-SE extension (Neogene); Nearly N-S compression and E-W extension (Holocene). On the other hand, only some of the studied faults present evidence of Neotectonic activity. In fact, most of the surveyed faults are closed or mineral-filled, suggesting they are old or were not recently reactivated. The preliminary results of this work suggest the important role of inherited (Pre-Cambrian) crustal weakens crustal zone probably reactivated in Cenozoic and also in the Neotectonic stress regime. Further detailed studies and field surveys are still necessary to highlight the role of the current Neotectonic regime on the present-day Brazilian landscape as well as to better define the geographic extent and location of the E-W shear corridor.</p>

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Don’t Put Me in This Group

2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke
Keyword(s):  
Positive Emotions ◽  
Negative Emotions ◽  
Negative Information ◽  
The Self ◽  
The Other ◽  
Other Hand ◽  
Group Memberships

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.

ON THE OTHER HAND

1961 ◽  
Vol 6 (6) ◽  
pp. 222-223
Author(s):  
Edwin G. Boring
Keyword(s):  
The Other ◽  
Other Hand
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