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Ganpat S. Roonwal Ph.D. 《International Journal of Earth Sciences》1972,61(1):282-301
A study of the trace elements in the Singhbhum granite from its northern borders (Saraikela) and the central mass (Chaibasa) reveals that there are differences not only in the limit of concentration but also in their behaviour. It is found that while correlating with the petrographic and also the major elements behaviour, the trace elements always do not mark an increase or decrease during the various stages of the evolution of the Singhbhum granite. The behaviour of the trace-elements as revealed from the previous studies relating to both igneous and metamorphic rocks, is significant in working out the physico-chemical factors involved in the genesis of rocks. In the magmatic rocks, the trace elements obviously follow a trend and go in accordance withGoldschmidt's principles of camouflage, capture and admission. In the present study such uniformities are not found. The present study reveals firstly, the different nature of chemical gradients formed by these elements during different geological environments; secondly, the mutual relationships and the ratio of certain traceelements in the different associations, indicating the original heterogeneity of these rocks and their formation under different geological as well as physico-chemical conditions. It has been concluded (Roonwal, 1968) that the rocks studied here as representing parts of Singhbhum granite do not form one granite series as referred to byRead. In fact they represent rocks formed from material having originally different lithological composition.The trace elements determined for the present study are Va, Cr, Ga, Y, In, Sc, Co, Ni, Cu, Ba, Sr, Sn, Pb and Zr. Among these Ga, Y, In and Sc do not show the normal behaviour viz., Ga should be more in granites but is found to be more in the basic representatives. Y is also more in the basic parts than in the granites. The present granites are very poor in In. Similarly whilst the granites should not normally be rich in Sc, in the present case the distribution of Sc in basic representatives as well as the true granitic parts is more or less uniform. The behaviour of Cu limits the application ofGoldschmidt's rule to magmatic rocks. The behaviour of other elements is normal. Pb shows an antipathic relationship with K+ and Ca+2 and indicates that it has not changed the position due to granitization. An inverse relationship between Zr+4 and Si+4 is observed which indicates the formation of zircon and has been in conformity with mineralogy of the rocks.
For a preliminary account, seeRoonwal (1968). The details of petrology and the major elements are being published elsewhere. 相似文献
Zusammenfassung Eine Untersuchung der Spurenelemente in Gesteinen aus den nördlichen Randgebieten (Saraikela) und der zentralen Masse (Chaibasa) des Singhbhum-Granites zeigte, daß Unterschiede nicht nur hinsichtlich der Konzentrationsgrenzen, sondern auch im Verhalten der Spurenelemente bestehen. Bei einer Korrelation des petrographischen Verhaltens mit dem der Hauptelemente wurde festgestellt, daß die Spurenelemente im allgemeinen keine Zu- oder Abnahme während der verschiedenen Evolutionsstadien aufweisen. Das Verhalten der Spurenelemente, ersichtlich aus früheren Untersuchungen von Intrusiv- und metamorphen Gesteinen, ist bedeutsam für die Feststellung der physiko-chemischen Faktoren, welche bei der Genese der Gesteine mitwirkten. In magmatischen Gesteinen folgen die Spurenelemente offensichtlich dem Trend vonGoldschmidts Regel der Camouflage, capture and admission. Bei der vorliegenden Untersuchung wurde eine solche Übereinstimmung nicht festgestellt. Die Untersuchung enthüllt erstens eine durch diese Elemente während verschiedener geologischer Umweltverhältnisse hervorgerufene verschiedene Natur der chemischen Gradienten und ließ zweitens ein gegenseitiges Verhältnis und das Verhältnis gewisser Spurenelemente in verschiedenen Gesteinsgesellschaften erkennen, was auf die ursprüngliche Heterogenität dieser Gesteine und deren Bildung unter verschiedenen geologischen sowie physiko-chemischen Bedingungen hinweist. Es wurde daraus geschlossen (Roonwal, 1968), daß die untersuchten Gesteine, welche den typischen Singhbhum-Granit repräsentieren sollen, nicht nachRead eine einzige Granitserie bilden, sondern daß sie Gesteine darstellen, welche ursprünglich aus Material verschiedener lithologischer Zusammensetzung stammen.Für diese Untersuchung wurden die folgenden Spurenelemente bestimmt: Va, Cr, Ga, Y, In, Sc, Co, Ni, Cu, Ba, Sr, Sn, Pb, Zr. Von diesen zeigen Ga, In und Sc nicht das normale Verhalten, da Ga eigentlich in größeren Mengen in Graniten auftreten sollte, was jedoch im vorliegenden Falle für die basischen Gesteinsvertreter zutrifft. Ebenfalls ist Y zahlreicher in den letzteren Vertretern vorhanden. Die vorliegenden Granite sind sehr arm an In, während sie andererseits normalerweise auch nicht reich an Sc sein sollten. Hier ist die Verteilung von Sc in den basischen Vertretern sowie auch in den wirklichen Granitanteilen mehr oder weniger gleichmäßig. Das Verhalten von Cu schränkt die Anwendung vonGoldchmidts Regel in bezug auf magmatische Gesteine ein. Das Verhalten anderer Elemente ist normal; Pb zeigt eine antipathische Beziehung zu K+1 und Ca+2, was darauf hinweist, daß es als Folge der Granitisation seine Position nicht geändert hat. Es wurde ein umgekehrtes Verhältnis zwischen Zr+4 und Sr+4 beobachtet, was auch die Bildung von Zirkon beweist und was durchaus der Mineralogie dieser Gesteine entspricht.
Résumé L'étude des éléments mineurs (traces) des roches de la région septentrionale aux environs de Saraikela et des massifs centraux de Chaibasa révèle une différence, non seulement dans le mode de concentration des éléments, mais également dans leurs caractères. Il apparaît, d'après la corrélation des études pétrographiques et les éléments principaux (major), que les éléments mineurs n'ont subit aucune augmentation ou diminution pendant les différentes phases de l'évolution.Le comportement des éléments mineurs, selon des études antérieurs de roches éruptives et de roches métamorphiques, est significatif dans la détermination des facteurs physico-chimiques qui contribuèrent à la génèse de ces gisements. Quant aux roches d'origine magmatique, les éléments mineurs suivent apparemment la tendance au principe deGoldschmidt « camouflage, envahissement et admission ». Mais l'étude actuelle n'a pas permis d'établir une telle conformité.L'étude de ces éléments révèle: premièrement, les différents caractères d'ordre chimique pendant les époques géologiques; deuxièmement les relations mutuelles et les rapports de certains éléments mineurs dans différentes associations; ceci indique l'hétérogénéité primordiale de ces roches et leur formation sous diverses conditions d'ordre géologique et physico-chimique.En conclusion (Roonwal, 1968), les roches étudiées figurant le granite-type de Singhbhum, ne forment pas la moindre série de granite — comme le ditRead — mais constituent des roches engendrées par les matériaux de différentes compositions lithologiques.De par ces études, il a été déterminé les éléments suivants: Va, Cr, Ga, Y, In, Sc, Co, Ni, Cu, Ba, Sr, Sn, Pb et Zr. Parmi ces éléments, Ga, In et Sc ne se rencontrent pas de façon normale puisque Ga devrait en réalité être plus répandu dans les roches granitiques ce qui pourtant s'avère dans le cas du substitut basique. De même, y se trouve en plus grande quantité dans les derniers substituts. Les granites de la région sont pauvres en In et riches en Sc — bien que le contraire soit attendu en ce qui concerne le Sc. Ici, la distribution de Sc, aussi bien dans les substituts basiques que dans les roches granitiques est plus ou moins régulière. Le comportement du Cu suit l'application de la loi deGoldschmidt sur les roches magnétiques; celui des autres éléments est normal; le plomb montre de l'antipathie pour les ions K+ et Ca+2, ceci indique qu'il n'a pas changé sa position par suite de la granitisation du magma. On observe une relation inverse entre Zr+4 et Sr+4, relation indiquant la formation de zircon en concordance avec la minéralogie de ces roches.
Sakaikela Chaibasa Singhbum , , . , , , . , , - , . : Camoflage, capture and admission. . , , -, , , , - , , , - . (Roonwal, 1968), , Singhbum, Read'a , , , . : V, Cr, Ga, Y, In, Sc, Co, Ni, Cu, Ba, Sr, Pb, Zr. Ga, In Sc. , Ga , . . In, , . , , . . — . Pb K Ca, , Pb . Zr4+ Sr4+, , .
For a preliminary account, seeRoonwal (1968). The details of petrology and the major elements are being published elsewhere. 相似文献
2.
G. S. Lodha K. J. S. Sawhney H. Razdan D. P. Agrawal N. Juyal 《Journal of Earth System Science》1987,96(2):135-145
Major and trace element concentrations of a few representative loess profiles in Kashmir valley are studied using EDXRF spectroscopy.
Principal component analysis for pattern recognition has been employed to study association between elemental concentration
variations in various horizons. The present study reveals that elements related to clay illuviation (K, Rb, Fe, Ti, Mn) and
plant activity (Cu, Zn) are generally higher in B horizon of the palaeosols whereas Ca and Sr have a high concentration in
the loess layers. Such an elemental concentration variation provides us with an objective index for identification and confirmation
of palaeosols. There is further a close association in the movement of (i) K, Rb, (ii) Fe, Ti, Mn, (iii) Cu, Zn and (iv) Ca,
Sr. These clusters of elements are also present in modern soils, suggesting that the soil characteristics in palaeosols have
been preserved. Concentration of iron and titanium is also observed to be higher in loess profiles on Pir Panjal mountain
flank which is dominated by basic rocks, compared to profiles on Himalayan flank, suggesting that the loess in Kashmir might
have been derived from the nearby rocks in a localized way. 相似文献
3.
Archna Sagdeo S. K. Rai Gyan S. Lodha K. P. Singh Nisha Yadav R. Dhawan Umesh Tonpe M. N. Vahia 《Experimental Astronomy》2010,28(1):11-23
X-ray reflectivity measurements were performed on several thin foil gold mirrors fabricated in TIFR for a Soft X-ray Imaging
Telescope. The mirrors were made from thin aluminum foils with a reflecting layer of sputtered gold transferred from a smooth
glass mandrel using an epoxy. X-ray reflectivity measurements were performed on a sample of randomly selected mirrors using
CuK
α
(8.05 keV), CrK
α
(5.41 keV) X-rays and also at several energies in the energy range of 155–300 eV using the synchrotron source Indus-1. It
was found that the roughness of the low-density top gold layer as obtained from the fitting of X-ray reflectivity data for
CuK
α
radiation is relatively more as compared to that obtained from the CrK
α
radiation. This indicates that in the mirrors made by this process, the upper surfaces are smoother as compared to the deeper
layers. It was also observed that the critical angle almost vanishes in the very low energy range of 290–300 eV due to strong
absorption effects of the low density material sitting on top of these mirrors. Due to this absorption effect, efficiency
of these mirrors reduces in this energy range. This is first time that reflectivity measurements are being reported for very
soft X-rays (≤ 300 eV) for mirrors made for any X-ray astronomy mission. 相似文献
4.
Surface reflection seismic techniques have the capability of mapping subsurface geological features without disturbing the rock mass. They also have an added capability of penetrating to a much deeper depth than any other geophysical technique, including the ground probing radar. However, the successful application of reflection seismic techniques in crystalline rocks has in general been more difficult than in sedimentary basins, because of the irregular geometry and low acoustic impedance contrasts across geological boundaries. In this paper, we describe the imaging of fracture zones in crystalline rocks. Effective data processing, carefully modified from the conventional approaches, was applied on two high-resolution field data previously collected by different contractors. The strategy included enhancement of the signal hidden under the large-amplitude scattering noise, through pre- and post-stack processing such as shot f-k filtering, residual statics and careful muting after NMO correction. Two sets of low S/N test data from Canada and Sweden are analyzed in this research. The reflected energy in these data sets appeared to be more closely related to fracturing than to lithologic boundaries. The major fracture zones at shallow depth have been mapped with the desired resolution and can be correlated to the available well-log and seismic crosshole tomographic data. Once the surface waves were removed, shallow reflectors in the fracture zones could be identified and analyzed on the field records. Focusing analysis of the seismic image was performed in the constant-offset section to investigate the trends of major fracture zones. The complex attributes were also analyzed to determine whether they could be applied to the shallow fracture zones. Instantaneous frequency plots outline the intense fracturing zone and instantaneous phase plots identify the major and minor fractures, and other coherent events with different dip attitudes which interfere with each other. 相似文献
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