Поиск по книгам
Автор(ы):Stel H, Veenhof R.P.
Издание:Elsevier, 1991 г., 14 стр.
Язык(и)Английский
A cleavage triple point and its meso-scopic structures: the Mustio Sink (Svecofennides of SW Finland)

Veenhof, R.P. and Stel, H.. 1991. A cleavage triple point and its meso-scopiс structures: the Mustio Sink (Svecofennides of SW Finland) Precambrian Res., 50: 269-282,

A cleavage-triple-point (CTP) structure is analyzed, located at the west side of the Mustio gneiss dome in the Svecofennides of southwest Finland. The presence of the CTP and the pattern of mesoscopic fold structures exclude the origin of the Mustio dome by successive interference of fold phases. The highly variable deformation structures are explained in a single-phase deformation model by using the theoretical specific strain environments ofa CTP. These environment are (1) horizontal oblation on lop ofa dome, (2) transition from horizontal to vertical obiation on ihe flanks ofa dome, and (3) vertical constriction in the center of the CTP, It is shown that each strain environment is associated with specific development of foliation, folds, mesoscopic fold interference and strain intensity. The theoretical strain environments are confirmed by strain analysis.


Издание:UNESCO, Paris, 1996 г., 133 стр., ISBN: 92-3-103085-X, 92-3-104013-8
Язык(и)Английский
A global geochemical database for enviromental and resource managment / Глобальная геохимическая база данных для рационального использования ресурсов и окружающей среды

“Prevention is better than cure” has been the leitmotiv of UNESCO, since its creation, in addressing world problems: prevention through education at all levels and in all sectors, the advancement of science and its applications, cultural development and adequate information. Whether in facing wars, conflicts or in coping with hazards, natural and technological in origin, UNESCO has constantly favoured an educational, scientific and cultural approach that sees anticipation as the only possible solution. It is the only possible cost-effective way of dealing with potential risks and disasters. It is of vital importance that the world community takes the long-term view and learns to be proactive rather than reactive.

Том 39, Выпуск 4
Издание:Москва, 2005 г., 7 стр.
Язык(и)Английский
A New Record of an Azhdarchid (Pterosauria: Azhdarchidae) from the Upper Cretaceous of the Volga Region

A distal fragment of a radius of Azhdarchidae indet. from Upper Campanian (Upper Cretaceous) marine deposits of Saratov is described. The bone belongs to a large pterosaur, of about 4.3 m wing span. It differs from the radii of Azhdarcho, Montanazhdarcho, and cf. Quetzalcoatlus in the asymmetrical distal epi-physis and, in addition, from Montanazhdarcho and cf. Quetzalcoatlus in the absence of a pneumatic foramen on the posterior side. In its geographical and stratigraphical positions, this specimen is close to the azhdarchid Bogolubovia orientalis (3–4 m in wing span), known from a fragmentary cervical vertebra from the Campanian of the Penza Region, and may belong to this species.

Выпуск 55
Автор(ы):Xiaoling W., Yinxiu L.
Издание:Journal of Geochemical Exploration, 1995 г., 5 стр.
Язык(и)Английский
A rapid field analytical method for gold in geochemical exploration

A rapid field method for gold analysis in geochemical exploration has been developed. Cold extraction of Au, at room temperature, using a mixture of sodium bromide, sulphuric acid, hydrogen peroxide is performed; the technique has the advantage of avoiding the irritating odour of commonly used aqua regia digestion. Polyurethane foam is used to concentrate gold from solution. After desorption of Au using mixed reagents (0.5% Na2S03-NaCl solution at pH 8), two sequential procedures, depending on the concentration, are followed for the determination of gold. (1) A 1 mL portion of desorbed solution is used to form Au-TMK-DBS (Thio Micher's Ketone and dodecyl benzene sodium sulphonate) ternary complex. Concentrations below 20 ng/g Au are determined by visual colour comparison of the organic layer with a series of standards. (2) If the concentration is greater than 20 ng/g Au, a complexation reaction using the same reagents is followed by fibre-optic colorimetry. The method is rapid and simple, and the tiresome operation of ashing the foam is avoided. The limit of detection is 0.5 ng/g Au and eighty determinations can be made in one working day. The method could be used for rapid follow-up of rock sample or in situ drill core analyses. About 600 samples from 5 gold districts were tested by this method. The results are very satisfactory.


Автор(ы):Steve C.Brown
Издание:PGS Publishing, Linden Park, 2005 г., 16 стр.
Язык(и)Английский
A Review of the Geology and Mineralisation of the Alumbrera Porphyry Copper-Gold Deposit, Northwestern Argentina.

The Bajo de la Alumbrera porphyry copper-gold deposit is located within the northern Sierras Pampeanas in the eastern Andes Mountains of northwestern Argentina. It formed in a tectonically favourable location within a major arc-oblique wrench fault system, the Tucuman Transfer Zone. Initial andesitic volcanism deposited on crystalline Lower Palaeozoic basement, and subsequently emplaced dacitic subvolcanic stocks are directly related to eastward subduction of the Nazca oceanic plate beneath the western continental margin of South America. Structural preparation and shallowing of the angle of subduction of the Nazca plate -related to the arc-normal Juan Fernandez Ridge on that plate - probably aided the ascent of calc-alkaline oceanic arc-related magma into the Tucuman Transfer Zone.

Издание:PGS Publishing, Linden Park, 2002 г., 11 стр.
Язык(и)Английский
A Short Review of Palaeozoic Hydrothermal Magnetite Iron-Oxide Deposits of the South and Central Urals, and their Geological Setting

The Urals orogen represents the site of Palaeozoic oceanic crust creation and subsequently a zone of arc development, arc-continent collision, continent-continent collision and post-orogenic collapse. The orogen is host to a number of world-class VMS deposits in the Silurian to Devonian arc sequences but in addition is host to highly significant iron oxide deposits of both hydrothermal and orthomagmatic origin. The hydrothermal ores are developed in Palaeozoic belts associated with rift-related, dominantly mafic, largely subaerial, alkaline volcanism intruded by comagmatic stocks of varying ages, from the Late Silurian to Early Carboniferous. Volcanism, sedimentation and mineralisation all seem to be controlled by major N to NNE trending structures. Much of the mafic volcanic sequence shows hematisation, which is evidence of early oxidation of the lava-tuff packages. Mineralisation comprises massive and disseminated magnetite bodies with elevated REE and ubiquitous accessory apatite. The deposits can be huge, as for example the giant Carboniferous Kachar deposit in Kazakhstan with reserves of over a billion tonnes of >45% Fe are defined. Some of the bodies are true contact skarns developed at the interface between intrusive bodies and volcano-sediments which include limestones. Other bodies, including Kachar, are distal to any possible related intrusions and are developed within regionally extensive scapolite alteration zones. A regionally consistent pattern of early feldspar ± biotite alteration followed by ore-stage pyroxene-garnet-scapolite followed by late hydrous silicate-carbonate alteration is repeated throughout the Urals. Regionally extensive scapolitisation is common in most of the belts. Base metals are generally present in the deposits, often appearing late in the paragenetic sequence, with some bodies having near economic copper grades (0.6% Cu) and significant precious metals.

Издание:PGS Publishing, Linden Park, 2005 г., 18 стр.
Язык(и)Английский
A Tectonic Model for Porphyry Copper-Molybdenum-Gold Deposits in the Eastern Indo-Asian Collision Zone

Two Himalayan porphyry copper-molybdenum-gold belts have been developed in the eastern part of the Himalayan-Tibet orogenic zone related to the collision between the Indian and Asian Plates. Both were accompanied by the emplacement of high-level intracontinental, alkali-rich, potassic felsic magmas which produced a huge Cenozoic belt of potassic igneous rock. The emplacement of these magmas was controlled by large-scale strike-slip fault systems, orientated roughly orthogonal to the of the Indo-Asian continental convergence, which adjusted the collisional strain. The Jomda-Markam-Xiangyun copper-molybdenum belt is the western of the two, developed along a narrow zone following the Nanqian thrust, the Jinshajiang fault system, and the Red River shear zone, whereas the eastern, the Zhongdian-Yanyuan-Yao'an porphyry copper-gold-silver belt, was developed along the western margin of the Yangtze Craton. The ore-bearing porphyries have compositions which include granite, monzogranite, and monzonite, with a small amount of quartz-syenite porphyry. They are distinguished from barren porphyries by their higher Si02 (>63 wt %), lower Y (<20 ppm) and their adakitic magma affinity. All alkali-rich porphyries are relatively enriched in large-ion lithophile elements (K, Rb and Ba) and depleted in high-field strength elements (Nb, Ta, Ti and P) with a wide range of Nb/Y ratios.

Издание:International Association for Gondwana Research, 2002 г., 20 стр.
Язык(и)Английский
A Vendian-Cambrian Island Arc System of the Siberian Continent in Gorny Altai (Russia, Central Asia)

An extended Vendian-Cambrian island-arc system similar to the Izu-Bonin-Mariana type is described in the Gorny Altai terrane at the margin of the Siberian continent.

Three different tectonic stages in the terrane are recognized. (1) A set of ensimatic active margins including subducted oceanic crust of the Paleo-Asian ocean, the Uimen-Lebed primitive island arc, oceanic islands and seamounts: the set of rocks is assumed to be formed in the Vendian. (2) A more evolved island arc comprising calc-alkaline volcanics and granites: a fore-arc trough in Middle-late Cambrian time was filled with disrupted products of pre-Middle Cambrian accretionary wedges and island arcs. (3) Collision of the more evolved island arc with the Siberian continent: folding, metamorphism and intrusion of granites occurred in late Cambrian-early Ordovician time. In the late Paleozoic, the above-mentioned Caledonian accretion-collision structure of the Siberian continent was broken by large-scale strike-slip faults into several segments. This resulted in the formation of a typical mosaic-block structure.

Выпуск 20
Редактор(ы):Osmolska H.
Издание:Panstwowe Wydawnictwo Naukowe, Warszawa, 1975 г., 139 стр.
Язык(и)Английский
Acta paleontologica Polonica. Vol XX

Relatively frequently found, the specimens of Homalonotinae are, in general, poorly preserved and, therefore, they are among the groups of trilobites that have so far been rather insufficiently studied. Since their occurrence is limited to the Llandovery through Middle Devonian, they may serve as a good index fossil. Their paleogeographical and correlative importance in the Upper Silurian and Lower Devonian was discussed separately (Tomczykowa, 1974).

The materials, on which the present paper is based, were collected by the writer in 1956—1958 in the Holy Cross Mts. Most of them, however, come from the boreholes managed by the Geological Institute, that is, from Goldap, Bostow, Ciepielow, Bialopole, Krowie Bagno, Lopiennik, Strzelce IG-2 and Zakrzew IG-3, as well as from the drillings of the Oil Research Survey (Malochwiej and Rozkopaczew boreholes) (Text-fig.  1). <...>

Том 1
Автор(ы):Марфунин А.С.
Издание:Springer-Verlag, Berlin, 1994 г., 550 стр., ISBN: 3-540-57254-6; 0-387-57254-6
Язык(и)Английский
Advanced mineralogy. Composition, structure and properties of mineral matter. Vol 1.

All existing introductory reviews of mineralogy are written according to the same algorithm, sometimes called the "Dana System of Mineralogy". Even modern advanced handbooks, which are certainly necessary, include basic data on minerals and are essentially descriptive. When basic information on the chemistry, structure, optical and physical properties, distinguished features and para-genesis of 200-400 minerals is presented, then there is practically no further space available to include new ideas and concepts based on recent mineral studies.

A possible solution to this dilemma would be to present a book beginning where introductory textbooks end for those already familiar with the elementary concepts. Such a volume would be tailored to specialists in all fields of science and industry, interested in the most recent results in mineralogy.

This approach may be called Advanced Mineralogy. Here, an attempt has been made to survey the current possibilities and aims in mineral matter investigations, including the main characteristics of all the methods, the most important problems and topics of mineralogy, and related studies.

The individual volumes are composed of short, condensed chapters. Each chapter presents in a complete, albeit condensed, form specific problems, methods, theories, and directions of investigations, and estimates their importance and strategic position in science and industry.

2016.84