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Выпуск 88
Издание:Economic geology, 1993 г., 25 стр.
Язык(и)Английский
40Ar/39Ar, K/Ar, and Fission Track Geochronology of Sediment-Hosted Disseminated Gold Deposits at Post-Betze, Carlin Trend, Northeastern Nevada

The Post-Betze deposit of Nevada is the largest sediment-hosted disseminated gold deposit presently known, both dimensionally and in terms of contained metal. Ore occurs primarily as submicron-sized gold that is disseminated in altered sedimentary rocks of the Lower Paleozoic Roberts Mountains Formation. However, significant portions of the ore are present in altered monzonite of the Goldstrike stock. Alteration and mineralization were controlled by both structure and stratigraphy. Alteration began with early decarbonatization and was followed by silicification and, finally, argillization. Phyllosilicate mineral zoning grades from proximal kaolinite to kaolinite + sericite to unaltered rock.

Выпуск 90
Издание:Economic geology, 1995 г., 3 стр.
Язык(и)Английский
40Ar/39Ar, K/Ar, and fission track geochronology of sediment-hosted disseminated gold depositsat at Post-Betze, Carlin Trend, Northeastern Nevada - a reply

We appreciate the comments on our paper on the Post-Betze sediment-hosted disseminated gold deposit which indicate that clarification is required. Ilchik suggests alternative interpretations of our findings with regard to two main issues: the nature of the sill that we have described as "postore," and the absolute age of Post-Betze mineralization in the context of the overall spread in the dates presented in our paper. We address these issues in turn.

The postore sill, which we also loosely originally termed "dike," is important in that it brackets the timing of gold mineralization. Although Ilchik suggests that this intrusion predates mineralization, the weight of evidence is to the contrary. Whereas the postore sill is composition-ally similar to preore Goldstrike stock-equivalent rocks, it is texturally quite distinct. In fact, it was distinctive enough for us to map it out in the subsurface from drill core, something which we were unable to do for any of the other sills. Comparatively, the rock is little altered and it is the only one in the ore zone that retains primary bio-tite. Assays shown in figure 5 of Arehart et al. (1993) are the original assays done on 5-ft intervals before the core was logged; in some samples mineralized inclusions are present within the sample interval. More detailed analysis of this rock type, when clear of any inclusions of mineralized sedimentary rock, yields very low values for gold. This is true of samples from several core holes. In sharp contrast, the preore dikes and sills are all significantly altered and mineralized (i.e., well above background in areas of sedimentary rock mineralization), although they are generally of lower grade than the surrounding sedimentary rocks. We are well aware of the erratic nature of and lithologic control on gold mineralization in sediment-hosted disseminated gold deposits that are also seen at Post-Betze. Even taking this into consideration, it is clear that there is effectively no gold in the postore sill in comparison to significant gold in preore dikes and sills.

Автор(ы):Апродов В.А.
Издание:Москва, 1962 г., 206 стр.
Язык(и)Русский
6000 километров по Монгольской Народной Республике

Путевые записки советского геолога, совершившего в 1958 г. большое путешествие но Монгольской Народной Республике. Автору довелось побывать в самых отдаленных и труднодоступных районах страны. Он пересек горы Хангая и Монгольского Алтая, пустыню [оби. Путешествие, сопровождавшееся различными дорожными приключениями, позволило автору узнать многое о частых в Монголии землетрясениях, нарисовать в книге любопытную картину „жизни" земной коры па территории МНР.
Много внимания уделяет автор жизни монгольского народа, его древней культуре, успехам в строительстве социализма. В книге много ярких описаний природы, увлекательных рассказов, о животном и растительном мире.
Книга хорошо иллюстрирована оригинальными фотографиями, картами, графиками.

Редактор(ы):Иванова И.К., Нейштадт М.И.
Издание:Наука, Москва, 1973 г., 223 стр., УДК: 551.89
Язык(и)Русский
7-й конгресс INQUA во Франции. Итоги и материалы

Сборник содержит статьи советских участников VIII конгресса INQUA в Париже, посвященные различным проблемам комплексного изучения четвертичного периода, итогам предконгрессных экскурсий по различным регионам Франции, обзору работы INQUA и его комиссий, выставкам и изданиям к конгрессу.

Издание:РГГРУ, Москва, 2005 г., 183 стр.
Язык(и)Русский
75 лет геофизическому факультету МГРИ-РГГРУ

История геофизического факультета МГРИ-МГГРУ теснейшим образом связана со становлением геофизической службы в нашей стране. Геофизические методы начали интенсивно развиваться в двадцатых годах прошлого столетия как новые прогрессивные способы изучения земной коры на основе наблюдений различных физических полей, распределение или характер которых отражают влияние геологической среды – горных пород, слагающих земную кору, на том или ином участке исследований и отличающиеся друг от друга по физическим свойствам. Впервые эффективность геофизических методов в России была показана в процессе изучения Курской магнитной аномалии, где они применялись в больших объемах. В этих работах участвовал академик П.П. Лазарев, будущий академик Г.А. Гамбурцев, профессора А.И. Заборовский и Л.В. Сорокин, которые впоследствии вместе с профессорами В.И. Барановым и В.Ф. Бончковским приняли участие в создании геофизической специальности в МГРИ.

Источник:ГФФ МГРИ-РГГРУ
Автор(ы):Gallois R., Hart M.
Издание:Plymouth University, Plymouth, 2009 г., 25 стр.
Язык(и)Русский
8th International Symposium on the Cretaceous System. Field excurion to Beer, South-East Devon (Jurassic coast world heritage site)

In 2001 the Dorset and East Devon Coast was inscribed on the World Heritage List as a place of outstanding universal value on the basis of its geological succession, coastal processes and landforms and its place in the history of the development of geology (especially stratigraphy and palaeontology). Extending from Orcombe Point in the west to Studland in the east, this World Heritage Site's 85 miles of coastline contains a record of 185 million years of Earth history. <...>

Издание:Plymouth University, Plymouth, 2009 г., 39 стр.
Язык(и)Английский
8th International Symposium on the Cretaceous System. Field Excursion to Dorset & Isle of Wight

In 2001 the Dorset and east Devon Coast was inscribed on the UNESCO World Heritage List as a place of outstanding universal value on the basis of its geological succession, coastal processes and landforms and its place in the history of the development of geology (especially stratigraphy and palaeontology). Extending from Orcombe Point in the west to Studland in the east, this World Heritage Site's 85 miles of coastline contains a record of 185 million years of Earth history. At the time of the proposal being submitted to UNESCO there were discussions about whether the planned site could be extended westwards to Torquay, covering the Permian and the Devonian rocks of Teignmouth, Dawlish and Torquay or eastwards to include the Isle of Wight. For various reasons (mostly non-geological) it was decided not to expand the proposed site further, although the Isle of Wight would have been the natural extension of the site, including more of the Cretaceous succession as well as the marine Cenozoic succession of the Hampshire Basin. This excursion is, in reality, looking at what the expanded site would have included.

Редактор(ы):Карташов И.П., Нейштадт М.И., Никифорова К.В.
Издание:Наука, Москва, 1977 г., 233 стр., УДК: 551.79 (931)
Язык(и)Русский
9-й Конгресс INQUA в Новой Зеландии. Итоги и материалы

Сборник содержит статьи советских участников IX конгресса INQUA в Новой Зеландии, посвященные различным проблемам комплексного изучения четвертичного периода, итогам экскурсии вдоль западного побережья о. Северного, обзору работы INQUA и его комиссий, выставкам и изданиям к конгрессу.

Автор(ы):Nolet G.
Издание:Cambridge University Press, 2008 г., 359 стр., ISBN: 978-0-521-88244-6
Язык(и)Английский
A breviary of seismic tomography. Imaging the interior of the Earth and Sun / Основы сейсмотомографии. Визуализация Земли и Солнца

This is the first textbook to cover all the major aspects of seismic tomography at a level accessible to students. While focusing on applications in solid earth geophysics, the book also includes numerous excursions into helioseismology in order to demonstrate the strong affinity between the two fields. The book presents a comprehensive introduction to seismic tomography including the basic theory of wave propagation, the ray and Born approximations required for interpretation of amplitudes, travel times and phases, eigenvibrations and surface waves, observational methods, model parametrization, finite-frequency methods, inversion, error and resolution analysis, and seismic anisotropy. It presents in-depth consideration of observational aspects of the subject, as well as practical recommendations for implementing numerical models using publicly available software.

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.


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