Comparison of structures in zircons from lunar and terrestrial impactitesThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.

2011 ◽  
Vol 48 (2) ◽  
pp. 107-116 ◽  
Author(s):  
R. T. Pidgeon ◽  
A. A. Nemchin ◽  
S. L. Kamo
Keyword(s):  
Careful Examination ◽  
Special Issue ◽  
Progressive Development ◽  
Internal Structures ◽  
Impact Ejecta ◽  
Deformation Features ◽  
Post Shock ◽  
Qualitative Measure ◽  
The Impact ◽  
Planar Deformation Features

There have been a number of reports of the presence of shock features, such as planar fracturing and granulation, the transformation of zircon to reidite, and the breakdown of zircon to baddeleyite in zircons associated with terrestrial impacts. It has also been proposed that the progressive development of these shock features, and the degree of disturbance of the zircon U–Pb isotopic system, could be used as a qualitative measure of the shock pressures and post-shock temperatures of the impact. Such behaviour of zircon from terrestrial impacts could be potentially useful in interpreting structures and U–Pb isotopic behaviour of shocked zircons from lunar impactites. However, careful examination of over one hundred zircon grains from samples of lunar breccias from Apollo 14 and 17 have not revealed any grains with terrestrial-like shock features, such as planar deformation features (PDFs), and we have not observed the high-pressure zircon phases reidite or the breakdown of zircon to baddeleyite in zircon grains from the breccias. Most lunar zircon grains show no evidence of a disturbance of their U–Pb systems. However, we have identified a few zircons from lunar breccias that have characteristic internal structures and accompanying Pb loss that we attribute to extreme shock. These structures differ from shock features reported for zircons associated with terrestrial impacts. Whether terrestrial-like impact features were present in the lunar zircons and have been removed during transport and heating in the impact ejecta, or whether these features never developed in the first place, has not been resolved.

scholarly journals A Study of Shock-Metamorphic Features of Feldspars from the Xiuyan Impact Crater

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 231
Author(s):  
Feng Yin ◽  
Deqiu Dai
Keyword(s):  
Impact Crater ◽  
Alkali Feldspar ◽  
Shock Temperature ◽  
Deformation Features ◽  
Post Shock ◽  
History Of ◽  
Temperature And Pressure ◽  
The Impact ◽  
Planar Deformation Features ◽  
Alkali Feldspars

Feldspar is the most abundant mineral in the Earth’s crust and is widely distributed in rocks. It is also one of the most common minerals in meteorites. Shock-metamorphic features in feldspar are widely used to calibrate the temperature and pressure of shock events and can also provide clues for searching for impact craters on Earth. In this study, shocked alkali feldspars in the lithic breccia and suevite from Xiuyan Impact Crater were investigated using polarizing optical microscopes, Raman spectroscopy and electron microprobes to better constrain the shock history of this crater. For this study, feldspar grains occurring in gneiss clasts in the impact breccia and four shock stages were identified, e.g., weakly shocked feldspar, moderately shocked feldspar, strongly shocked feldspar, and whole rock melting. According to the shock classification system for alkali feldspar and felsic rocks, we estimated the shock pressure (SP) and post-shock temperature (PST) histories of these gneiss clasts. Weakly shocked feldspars display irregular fractures and undulatory extinction, and their shock stage is F-S2, which indicates that SP and PST are from ~5 to ~14 GPa and ~100 °C, respectively. Moderately shocked feldspars show planar deformation features and are partially transformed into diaplectic glass, which indicates that the F-S5 shock stage of SP and PST is from ~32 to ~45 GPa and 300–900 °C. Strongly shocked feldspars that occur as vesicular glass indicate a shock stage of F-S6, and the SP and PST are 45–60 GPa and 900–1500 °C, respectively. The whole felsic rock melting occurs as mixed melt glass clast and belongs to the F-S7 stage, and SP and PST are >60 GPa and >1500 °C, respectively.

The Cleanskin impact structure, Northern Territory and Queensland, Australia: A reconnaissance study

2021 ◽  
Author(s):  
T. Kenkmann ◽  
P.W. Haines ◽  
I.P. Sweet ◽  
K. Mitchell
Keyword(s):  
Remote Sensing ◽  
Northern Territory ◽  
Impact Structure ◽  
Impact Event ◽  
Deformation Features ◽  
Apparent Diameter ◽  
The Impact ◽  
Planar Deformation Features ◽  
Impact Origin ◽  
Quartz Grains

ABSTRACT We report on the Cleanskin structure (18°10′00″S, 137°56′30″E), situated at the border between the Northern Territory and Queensland, Australia, and present results of preliminary geological fieldwork, microscopic analyses, and remote sensing. The Cleanskin structure is an eroded complex impact structure of ~15 km apparent diameter with a polygonal outline caused by two preexisting regional fault sets. The structure has a central uplift of ~6 km diameter surrounded by a rather shallow ring syncline. Based on stratigraphy, the uplift in the center may not exceed ~1000 m. The documentation of planar deformation features (PDFs), planar fractures (PFs), and feather features (FFs) in quartz grains from sandstone members of the Mesoproterozoic Constance Sandstone confirms the impact origin of the Cleanskin structure, as proposed earlier. The crater was most likely eroded before the Cambrian and later became buried beneath Cretaceous strata. We infer a late Mesoproterozoic to Neoproterozoic age of the impact event. In this chapter, the Cleanskin structure is compared with other midsized crater structures on Earth. Those with sandstone-dominated targets show structural similarities to the Cleanskin structure.

scholarly journals Shocked quartz in distal ejecta from the Ries impact event (Germany) found at ~ 180 km distance, near Bernhardzell, eastern Switzerland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sanna Holm-Alwmark ◽  
Carl Alwmark ◽  
Ludovic Ferrière ◽  
Matthias M. M. Meier ◽  
Sofie Lindström ◽  
...  
Keyword(s):  
Impact Structure ◽  
Impact Cratering ◽  
Impact Ejecta ◽  
Deformation Features ◽  
Different Depths ◽  
Shocked Quartz ◽  
Depositional Age ◽  
Impact Events ◽  
Planar Deformation Features ◽  
Quartz Grains

AbstractImpact ejecta formation and emplacement is of great importance when it comes to understanding the process of impact cratering and consequences of impact events in general. Here we present a multidisciplinary investigation of a distal impact ejecta layer, the Blockhorizont, that occurs near Bernhardzell in eastern Switzerland. We provide unambiguous evidence that this layer is impact-related by confirming the presence of shocked quartz grains exhibiting multiple sets of planar deformation features. Average shock pressures recorded by the quartz grains are ~ 19 GPa for the investigated sample. U–Pb dating of zircon grains from bentonites in close stratigraphic context allows us to constrain the depositional age of the Blockhorizont to ~ 14.8 Ma. This age, in combination with geochemical and paleontological analysis of ejecta particles, is consistent with deposition of this material as distal impact ejecta from the Ries impact structure, located ~ 180 km away, in Germany. Our observations are important for constraining models of impact ejecta emplacement as ballistically and non-ballistically transported fragments, derived from vastly different depths in the pre-impact target, occur together within the ejecta layer. These observations make the Ries ejecta one of the most completely preserved ejecta deposit on Earth for an impact structure of that size.

Pengaruh Lintas Budaya Pada Pemasaran Internasional Dengan Pendekatan Perilaku Konsumen

2017 ◽  
Vol 1 (2) ◽  
pp. 168-176
Author(s):  
Endy Gunanto ◽  
Yenni Kurnia Gusti
Keyword(s):  
Consumer Behavior ◽  
Marketing Strategy ◽  
Consumer Culture ◽  
International Organization ◽  
Future Research ◽  
Special Issue ◽  
Cross Culture ◽  
Several Variables ◽  
Cultural Orientations ◽  
The Impact

In this article we present a conceptual of the effect of cross culture on consumer behavior incorporating the impact of globalization. This conceptual idea shows that culture inûuences various domains of consumer behavior directly as well as through international organization to implement marketing strategy. The conceptual identify several factors such as norm and value in the community, several variables and also depicts the impact of other environmental factors and marketing strategy elements on consumer behavior. We also identify categories of consumer culture orientation resulting from globalization. Highlights of each of the several other articles included in this special issue in Asia region. We conclude with the contributions of the articles in terms of the consumer cultural orientations and identify directions for future research.

Syrian Crisis and Migration

2015 ◽  
Vol 12 (3) ◽  
pp. 181-192 ◽  
Author(s):  
Pinar Yazgan ◽  
Deniz Eroglu Utku ◽  
Ibrahim Sirkeci
Keyword(s):  
Human Mobility ◽  
Special Issue ◽  
Host Countries ◽  
Syrian Crisis ◽  
Mass Migration ◽  
Large Numbers ◽  
And Migration ◽  
Europe Today ◽  
The Impact ◽  
Near Future

With the growing insurrections in Syria in 2011, an exodus in large numbers have emerged. The turmoil and violence have caused mass migration to destinations both within the region and beyond. The current "refugee crisis" has escalated sharply and its impact is widening from neighbouring countries toward Europe. Today, the Syrian crisis is the major cause for an increase in displacement and the resultant dire humanitarian situation in the region. Since the conflict shows no signs of abating in the near future, there is a constant increase in the number of Syrians fleeing their homes. However, questions on the future impact of the Syrian crisis on the scope and scale of this human mobility are still to be answered. As the impact of the Syrian crisis on host countries increases, so does the demand for the analyses of the needs for development and protection in these countries. In this special issue, we aim to bring together a number of studies examining and discussing human mobility in relation to the Syrian crisis.

scholarly journals Fluvial Geomorphology and River Management

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1608
Author(s):  
Salvatore Ivo Giano
Keyword(s):  
Human Activities ◽  
River Restoration ◽  
Fluvial Geomorphology ◽  
Landscape Evolution ◽  
River Management ◽  
Special Issue ◽  
Fluvial Systems ◽  
The Impact

This Special Issue deals with the role of fluvial geomorphology in landscape evolution and the impact of human activities on fluvial systems, which require river restoration and management [...]

scholarly journals Editorial: Education in Europe and the COVID-19 Pandemic

2021 ◽  
Vol 20 (4) ◽  
pp. 393-402
Author(s):  
Sotiria Grek ◽  
Paolo Landri
Keyword(s):  
Global Health ◽  
Liberal Education ◽  
Education For All ◽  
Policy Debate ◽  
Special Issue ◽  
Current Crisis ◽  
New Era ◽  
European Education ◽  
The Impact ◽  
Research And Policy

Although the global Covid-19 pandemic is still affecting our lives enormously, we know that a new era of deep reflection about ‘normality’, our planet and our existence on it has also begun. The ‘Education in Europe and the Covid-19 Pandemic’ double Special Issue intends to be part of this reflexive discussion about the post-pandemic European education policy and research space. This is a space shaped continuously by crises and opportunities, by utopias of a shared progressive and liberal education for all, but also the dystopias of nationalism, populism, climate destruction and now a global health emergency. This editorial offers an overview of the current crisis context and of the articles; further, it positions the journal within the post-pandemic research and policy debate about how to understand the impact of the pandemic on the changing forms of education and its enduring inequalities.

scholarly journals Fast deformation of shocked quartz and implications for planar deformation features observed in shocked quartz

2020 ◽  
Author(s):  
Toshimori Sekine ◽  
Tomoko Sato ◽  
Norimasa Ozaki ◽  
Kohei Miyanishi ◽  
Ryosuke Kodama ◽  
...  
Keyword(s):  
Planar Deformation ◽  
Deformation Features ◽  
Shocked Quartz ◽  
Planar Deformation Features

Who Cares for the Family?

1978 ◽  
Vol 7 (3) ◽  
pp. 257-284 ◽  
Author(s):  
Hilary Land
Keyword(s):  
Labour Market ◽  
Domestic Workers ◽  
Careful Examination ◽  
Family Policies ◽  
Adult Men ◽  
The Family ◽  
The Disabled ◽  
Unpaid Labour ◽  
Maintenance Systems ◽  
The Impact

ABSTRACTAlthough Britain has never had a set of policies explicitly labelled ‘family policies’, most if not all social policies are implicitly family policies because they are based on certain assumptions about the nature of relationships between the sexes and the generations. By careful examination of the detail of the legislation and administrative rules, together with the way in which services are allocated and used, it is possible to expose these assumptions and show that they are not only consistent between policies but very persistent over time. This paper first examines the assumptions concerning the division of unpaid labour within the family whereby women care for the young, the sick and the old and for able-bodied adult men (their husbands). The examples are selected from a variety of income maintenance systems and services for children, the old and the disabled. Particular attention is focused on the extent to which it is recognized that women are at the same time workers in the labour market and unpaid domestic workers in the home. The second part of the paper analyses the impact on their participation and opportunities in the labour market of the ideology which accords to women the primary responsibilities for caring for other members of their family. The perpetuation of such an ideology favours the interests of men and frequently the interests of the economically powerful, but it is not assumed that these interests always coincide.

Translation, interpreting and the genealogy of conflict

2012 ◽  
Vol 11 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Luis Pérez-González
Keyword(s):  
Special Issue ◽  
Social Phenomena ◽  
The Public ◽  
Institutional Settings ◽  
Public Consciousness ◽  
The Media ◽  
Methodological Approaches ◽  
To Come ◽  
The Stability ◽  
The Impact

While the growing ubiquitousness of translation and interpreting has established these activities more firmly in the public consciousness, the extent of the translators’ and interpreters’ contribution to the continued functioning of cosmopolitan and participatory postmodern societies remains largely misunderstood. This paper argues that the theorisation of translation and interpretation as social phenomena and of translators/interpreters as agents contributing to the stability or subversion of social structures through their capacity to re-define the context in which they mediate constitutes a recent development in the evolution of the discipline. The consequentiality of the mediators’ agency, one of the most significant insights to come out of this new body of research, is particularly evident in situations of social, political and cultural confrontation. It is contended that this conceptualisation of agency opens up the possibility of translation being used not only to resolve conflict and tension, but also to promote them. Through a variety of theoretical and methodological approaches, the contributing authors to this special issue explore a number of sites of linguistic and cultural mediation across a range of institutional settings and textual/interactional genres, with particular emphasis on the contribution of translation and interpreting to the genealogy of conflict. The papers presented here address a number of overlapping themes, including the dialectics of governmental policy-making and translation, the interface between translation, politics and the media, the impact of the narrative affiliation of translators and interpreters as agents of mediation, the frictional dynamics of interpreter-mediated institutional encounters and the dynamics of identity negotiation.

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