An outline of shear-sense analysis in high-grade rocks

Ductile shear zones are important in tectonic reconstructions as a source of information on the relative motion of large crustal blocks or plates in the geological past. Methods to interpret fabric in ductile shear zones were mostly developed for low grade rocks where overprinting relations are usually well preserved. However, high grade shear zones are common and dominate in many Precambrian terrains. High grade shear zones should be analysed in a different way from low grade zones. The plane on which shear sense markers should be observed, the vorticity profile plane, is more difficult to find than in low grade shear zones. The most reliable shear sense markers in high grade shear zones are shear bands, mineral fish, mantled porphyroclasts, sigmoids and asymmetric boudins.     

Correspondence cluster analysis and its application in exploration geochemistry

Correspondence cluster analysis, developed in this paper, regroups the main advantages of correspondence analysis and cluster analysis. The output of the method, correspondence cluster dendrograms, shows clearly the relationships between variables, between samples, and between variables and samples, on a single diagram. The technique has been applied successfully to distinguish geochemical anomalies from background, to recognize types of anomalies, to study the geochemical characteristics of deposits, etc. Several practical examples presented in this paper show that the method can be used to classify elements and samples into meaningful groups, and that the geochemical character of each sample group can be interpreted in terms of the corresponding element group. The results are consistent with the geological situations at hand, and are usually more elucidating than other classification methods.     

Regional policy in Switzerland: an analysis of its effectiveness and an outline of a strategic reorientation

First, regional policy in Switzerland is examined theoretically. This is followed by a short review of those partial effects of this policy which, according to current empirical findings, can be regarded as proved. Finally, with the failings of present policy in mind, the basis for a strategically new concept is drawn up. Swiss regional policy is unlike that of other countries, in that it is not influenced by any one particular theory of regional economics. On the contrary, there is a combination of widely varying forms, especially a mixture of theoretical elements based on both neoclassicism and polarization. Viewed as a whole, this concept can be considered well-balanced, despite the criticisms brought forward here. A radical departure from the present concept appears neither necessary nor sensible, although the individual points of criticism show that to be really effective, present policy requires a few additions or shifts of emphasis. Thus regional policy should increasingly build on the region's existing potential, aiming for the broadest possible development and mobilization of local resources. This should enhance regional self-reliance, simultaneously, in economic, social-cultural, and political terms. In addition, appropriate measures should be taken to improve the innovative strength of peripheral regions. Finally, an essential aspect of strategic reorientation is increased attention to the problems of settlement structure in peripheral parts of the country. In this respect the promotion of small and medium-sized development centres deserves special attention.     

The construction and development of SHRIMP I: An historical outline

In 1973 Bill Compston advocated the building of an ion microprobe at the Research School of Earth Sciences (RSES) at the Australian National University (ANU). The commercial ion probes available at this time were too small to have sufficient sensitivity for trace element analysis and too low in mass resolution to avoid molecular interferences. The project commenced in 1974 with the appointment of a former ANU PhD student Steve Clement who had expertise in beam transport theory. To achieve high sensitivity and high mass resolution, beam transport theory indicated that a much larger magnet than in any commercially available mass spectrometer would be required. Clement chose an ion optical design, by Professor Matsuda of Osaka University in 1974, which had the required combination of high mass resolution and high transmission. Clement's job was to produce the detailed scientific designs and machine drawings for the new instrument as well as testing the completed instrument. Clement coined the term SHRIMP-Sensitive High Resolution Ion MicroProbe. By the end of 1977 nearly all the components had been manufactured and the big electromagnet had been successfully tested. In the following year the secondary mass analyzer was assembled and tested using a thermal ionization source and showed great promise with flat-topped peaks at 5000 resolution and 50% transmission with 50 V energy spread. At this stage the machine had far exceeded the specifications for the available commercial ion probes. Continued development during 1981 to the point where the original design specifications were fully realized was time consuming since learning how to use the entirely novel instrument was no simple task; no one else had an instrument like SHRIMP. The application of the instrument to zircon U–Pb geochronology established the necessary operating conditions for measuring Pb isotopic compositions and the elemental ratios Pb/U and U/Zr from 20 μm diameter spots on single zircon grains. Application of this in the early 1980s started a revolution in Precambrian geology by the ability to produce rapidly accurate and precise age determinations on structurally complex zircon samples.     

Developing perspectives upon the areal extent of Israel: An outline evaluation

This paper considers certain proposals for the future of the present Israeli-Occupied Territories. An essential yet brief review of various backgrounds, including the notion of Eretz Yisrael, is presented. The two principal Israeli viewpoints on the future of the territories, the Eretz Yisrael and the Regional Compromise positions are considered in some detail. While the so-termed Jordanian Option is outlined the Joshua Option is introduced as it may possibly indicate an even broader dimension for future deliberations and actions. A brief introduction to the proceeding study of Jewish settlement-development in the Samarian core is presented. The importance of such fieldwork is stressed. The overall contentious nature of the subject is emphasized yet academic consideration must proceed.     

An outline of the geology of the Afghan Pamirs

In the Great Afghan Pamir (Pamir-e Kaland) the following formations can be distinguished, from bottom to top: Wakhan Fm. (3000–4000 m thick anchimetamorphic slates and sandstones with frequent intercalations of quartzites and rare beds of crystalline limestones; conodonts of Lower Triassic); Qal'a-e Panja Tonalite (epimetamorphic, cataclastic); Qal'a-e Ust Gneiss (meta- and orthogneisses); Issik Granodiorite (batholite of the Afghan Pamirs, equivalent to Baba Tangi-Lunkho Granodiorite; xenoliths, flow structures and diaphtoritic portions; Upper Jurassic to Eocene). The tectonics are determined by the Peripheric Southern Fault of the Pamirs and the Wakhan Fault, showing vertical dislocation up to 1000 m and sinistral thrusting in connection with the Western Himalayan Syntaxis. Late Variscan and Alpine deformations and an intensive middle Alpine metamorphism can be observed. Interpretations of satellite pictures lead to an insertion of the regional tectonic features into the model of plate tectonics of the Himalayan arc.     

Fennoscandia — A short outline of its geodynamical development

Based on the strong heat flow in the Archaean and Proterozoic a concept for dynamical processes is developed that agrees with observation of low and high pressure metamorphism in ensialic belt of the Precambrian in Scandinavia and other old shield areas. Heat release is considered to have taken place predominantly at fast spreading oceanic ridges, some of them certainly adjacent to continental margins. Thinner, warmer, lighter, and faster oceanic plates descended with very small dip below the continent, leading to an underplating, to a decrease of the continental thermal gradient, and to a compressive stress with the tendency to keep the growing Archaean supercontinent together. Ensialic belts may have partly been created by a shallow secondary back-arc creep pattern. The general decrease of heat production and heat release continuously slowed all creep processes. At around 1000 ± 300 Ma, oceanic plates must have reached critical values of thickness, weight, and density to perform a real steep angle subduction, reinforced by sediment loads and phase transition at depth. A well developed plate tectonic pattern with an opening and closing of the lapetus ocean, with subduction, and a subsequent continent-continent collision can be inferred for the forming of the Caledonian-Appalachian mountain range. Even today, dynamical movements at asthenospheric levels below Fennoscandia are still present as indicated by observations of seismic travel time residuals, deep seismic soundings, gravity, compressive stresses, and theoretical calculations of temperature and viscosity.     

Expertise in the age of post-factual politics: An outline of reflexive strategies

What has become known as post-factual politics poses particular challenges to the role of expertise, calling for a new type of reflexivity able to inform scholarly strategies towards policy. Taking recent literature on the ‘practice turn’ as our point of departure, we argue for introducing a sense of ‘practical reflexivity’ that can provide guidance for the practice of scholars. Practical reflexivity focuses on the everyday practices of scholars rather than epistemic ideals or formal methodological rules. It directs our attention to the relation between academic and other practices. At this conjunction, several practical challenges arise. We discuss three major challenges and identify them as the epistemic, the autonomy and the performativity dilemmas. To seek answers to these, we explore the repertoire provided by three reflexive strategies outlined in neo-Gramscianism, Bourdieusian praxeology and pragmatism. The outcome is a tool for rethinking the relation between everyday practices of scholars and non-scholarly practices that may be usefully adopted in the current situation.     

Typological factor analysis: A new classification method applied to geology

The purpose of typological factor analysis is to detect, within a multidimensional sample, the existence of subsets characterized by different maximal elongation directions. The method which has been successfully applied in the field of pattern recognition can be considered from two points of view: (1) an automatic classification or dynamic clustering technique: and (2) a form of factor analysis. Using this form of analysis nuclei of affine varieties (points, axes, planes, etc) are identified. Different case studies were analyzed in order to establish the advantages of the method compared to other methods. Geochemical analyses of rock samples; that is, rhyolites, mafic, and intermediate rocks of the Normetal (Abitibi) area were subjected to typological factor analysis for the purpose of classification of geological deposits and detection of geochemical anomalies. The method was also applied to the classification of sediments from the Barataria Bay area in Louisiana.     

An oblique factor analysis solution for the analysis of mixtures

The problems involved in the factor analysis of data consisting of measurements of material quantity or proportion are discussed, and the inability of existing factor analysis solutions to properly model such data is pointed out. A new factor analysis solution using the linear programming technique is presented which properly analyzes mixture data. A numerical example is presented in which a body of suspended sediment grain-size distribution data is analyzed using the new factor analysis solution. FORTRAN-IV subroutines for computing this solution are included in an Appendix.     

An outline of studies on the Precambrian stromatolites of China

This paper outlines studies of Chinese Precambrian stromatolites, which may be subdivided preliminarily into two ‘stromatolite successions’ and seven assemblages.Secondly, based on Chinese data, stromatolites have undoubted stratigraphic significance for intrabasinal correlation, but it is necessary to depend on some of the ‘bridging elements’ and the ‘related assemblages’, as well as on other methods for interbasinal correlation.Finally, the paper discusses some problems of fossil stromatolites, i.e. the principal classification and the stromatolite cycles.     

An outline of population geography of Jiangsu province,China

"Jiangsu (Kiangsu) Province [China] is located in the lower reaches of the Yangtze River which divides it into two parts, South Jiangsu and North Jiangsu. The area of the province is 102,000 sq. km with a population of 60,521,114 and a density of 605 per sq. km in 1982. The area of Jiangsu is slightly larger than that of Hungary (93,000 sq. km). But the population is 5.7 times and the density of population 5.2 times larger than those of Hungary. This paper states the tendency of population growth, the geographical distribution and present condition of urban and rural population, discussing briefly the rational redistribution of [the] population of Jiangsu."     

滑坡稳定性分析的点安全系数法

建立滑坡数值计算的三维模型,将滑带离散为薄层8节点六面体单元,采用基于摩尔-库仑强度准则的理想弹塑性本构模型模拟滑带材料,通过数值计算,可获得滑带单元的三维应力状态和滑动方向。定义单元点安全系数为滑带单元抗剪强度与滑面上平行滑动方向的剪应力之比,定义滑坡整体安全系数为单元点安全系数对滑带面积的加权平均值。采用点安全系数分析滑坡的空间滑动机制,采用整体安全系数评价滑坡稳定性。算例分析表明,分析结果符合现场实际情况。     

The micro-scale simulation of maturation: outline of a new technique and its potential applications

A micro-analytical technique has been developed for artifically maturing sedimentary organic matter and then quantifying the major components generated during this process in a single analytical step. Such a capability is well-suited for examining the compositional relationships between kerogens and petroleums, determining reaction kinetics and making precursor-product mass balances. According to this technique, simulations are made using sealed glass capillary tubes (heated here for three days at 300 °C, 330 °C and 350 °C). Pyrolysis products are then released directly into a combined thermovaporisation/pyrolysis-GC instrument and the major components of the entire C₁ yto C³⁵ range can be quantified in a single step using gas chromatography. Alkene yields are very low and pyrolysates are oil-like. This is exemplified by the fact that then–C₉–C₁₉ alkane distribution range of simulated whole petroleum chromatograms, from originally immatureGloeocapsamorpha-typz alginite A, resembles that seen in crude oils generated from this same kerogen type in nature. Sealed tube experiments usingBotryococcus type alginite A generated a »high wax« pyrolysate. The relative abundance ofn-alkanes in the C₂–C₃₂ range of many kerogen pyrolysates does not appear to change significantly despite an approximately fifteen-fold difference inn-alkane yield between the 300 °C and 350 °C experiments. Kerogens which are »paraffinic« oil-prone, and whose pyrolysates are very rich inn-alkanes might therefore generate petroleums in nature with a fixed wet gas (C₂-C₄) to oil (C₅+) ratio. Alginite B in a Greenland shale is much more thermally labile than eitherBotryococcus-type alginite A orGloeocapsamorpha-type alginite A. The mass balance capabilities of the technique have been tested using Alum Shale kerogen. Two gas chromatograms were obtained, one for the free compounds generated during simulation, and one for the high temperature pyrolysate of the kerogen residue, for each heating experiment. Precursor-product relationships were qualitatively assessed, and dead carbon formation was quantified in this exercise.

---

Zusammenfassung Eine mikro-analytische Methode zur künstlichen Reifung sedimentärer organischer Substanz konnte entwickelt werden. Dabei werden die Hauptkomponenten, die während des Vorgangs freigesetzt werden, quantitativ erfaßt. Grundlagen dieser Methode sind Simulationen mit kapillaren Glasröhren, nach welchen die Pyrolyse-Produkte direkt in ein kombiniertes Thermovaporation/Pyrolyse-GC Instrument freigesetzt werden. Mit Hilfe der Gas-Chromatographie können in einem einzigen Schritt die Hauptkomponenten der gesamten C₁ bis C₃₅ Spannbreite quantitativ erfaßt werden. Kerogen-Typisierung und Abschätzung des Muttergesteinspotentials werden stark vereinfacht, wenn die Verhältnisse der Vorläufer-Produkte sorgfältig bestimmt und die chemisch-kinetischen Parameter für einzelne Komponenten, Komponentengruppen und/oder Siedepunktbereiche berechnet werden. Diese Anwendung stimmt mit Techniken im Makro-Bereich (z. B. Hydro-Pyrolyse) überein, aber die Vorteile der Annäherung im Mikro-Bereich liegen darin, daß geochemische Informationen schneller und bequemer gewonnen werden können und sehr kleine Probenmengen ausreichen. Ferner kann neben der Möglichkeit der singulären Anwendung die Annäherung im Mikro-Bereich dazu verwendet werden, Proben für detailierte und Labor-intensive Simulationen im Makro-Bereich effizient auszuwählen.

---

Résumé Les auteurs présentent une technique micro-analytique qui comporte la maturation artificielle de la matière organique sédimentaire suivie du dosage des composants majeurs ainsi engendrés. Dans le cadre de ce procédé, on réalise des simulations dans des tubes capillaires en verre, après quoi les produits de la pyrolyse sont libérés directement dans un instrument combiné de thermovaporisation/hydrolyse-GC et les composants majeurs de la lignée complète C₁ à C₃₅ peuvent être dosés en une seule opération de Chromatographie en phase gazeuse. De cette manière, la caractérisation du kérogène et l'estimation du potentiel de la rochemère sont grandement facilitées dans la mesure où les relations des produits précurseurs sont soigneusement établies et où il est possible de calculer les paramètres chimico-cinétiques pour des composants isolés, pour des groupes de composants et/ou les domaines de température où se situent les points d'ébullition. Ces procedures sont en accord avec celles des techniques macroscopiques (p.ex l'hydro-pyrolyse), mais l'avantage de l'approche microanalytique réside dans le fait que les résultats géochimiques sont obtenus plus rapidement et plus aisément et qu'il est possible de traiter de très petits échantillons. Enfin, nonobstant ses avantages propres, l'approche micro-analytique peut être utilisée à la sélection d'échantillons destinés à des simulations détaillées et laborieuses à l'échelle macroscopique.

---

. , . . _{1 35} . - - , / , , - . , .: , , . .

     

Climatic classification of Saudi Arabia: An application of factor -- Cluster analysis

This study is aimed to be a contribution to climatic regionalization of Saudi Arabia. The study applies a multivariate factor -- cluster analysis technique. The data used here have been obtained from 56 meteorological stations. The application of the technique is made into two stages. In the first stage, factor analysis alone is considered and its results in Saudi Arabia are discussed. In the second stage, the resultant factor scores are taken as an input in a cluster analysis process to obtain climatic regions. Thus the regions obtained in the second stage are a result of the integration of factor and cluster techniques. The results obtained by the technique are compared with those of some traditional methods. The factor-cluster analysis technique is found advantageous over many of those methods, as it produces richer regions and shows clear climate variations within this vast country.     

An outline tephrochronology for the Holocene of the north of Ireland

Geochemically typed thin layers of Icelandic Holocene tephras form a tephrochronology for the north of Ireland. Tephrochronology construction is based on geochemical linkage with dated historic Icelandic eruptions and high-precision multisample radiocarbon dating. Comparison with geochemically typed Holocene layers at sites throughout Scotland and northern England shows that some layers are widespread throughout much of the northern British Isles. Other layers of known historic date have so far been detected only in Ireland.