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Издание 2
Автор(ы):Richard H. Groshong
Издание:Springer, New York, 2006 г., 410 стр., ISBN: 3-540-065422-4
Язык(и)Английский
3-D Structural Geology. A practical guide to quantitative surface and subsurface map interpretation

Geological structures are three dimensional, yet are typically represented by, and interpreted from, outcrop maps and structure contour maps, both of which are curved two-dimensional surfaces. Maps plus serial sections, called 2½-D, provide a closer approach to three dimensionality. Computer technology now makes it possible for geological interpretations to be developed from the beginning in a fully three dimensional environment. Fully 3-D geological models allow significantly better interpretations and interpretations that are much easier to share with other geologists and with the general public. This book provides an overview of techniques for constructing structural interpretations in 2-D, 2½-D and 3-D environments; for interpolating between and extrapolating beyond the control points; and for validating the final interpretation. The underlying philosophy is that structures are three-dimensional solid bodies and that data from throughout the structure, whether in 2-D or 3-D format, should be integrated into an internally consistent 3-D interpretation.

Издание:Геокарт, Москва, 2005 г., 388 стр., УДК: 553.065, ISBN: 8-89118-396-X
Язык(и)Русский
400 миллионов лет геологической истории южной части Восточной Европы

Рассмотрена история развития южной части Восточной Европы - от юга Восточно-Европейской платформы до ее складчатого обрамления в Кавказско-Турецкой области - в интервале от девона до современного этапа. Детально исследованы вопросы палеогеографии, палеотектоники, магматизма и палеогеодинамики. Для кайнозойской истории Кавказско-Черноморского региона предложены численные геодинамические модели.

Для специалистов в области региональной геологии, геологов-съемщиков и поисковиков, студентов и преподавателей вузов

Выпуск 92
Издание:Economic geology, 1997 г., 22 стр.
Язык(и)Английский
40Ar/39Ar Dating and Mineral Paragenesis for Carlin-Type Gold Deposits along the Getchell Trend, Nevada: Evidence for Cretaceous and Tertiary Gold Mineralization

The orebodies at the Getchell and Twin Creeks mines were studied through mineral paragenesis, geologic relationships, and 40Ar/39Ar dating. Mineral paragenetic relationships are based on observations made during the logging of 18,000 m of drill cuttings and core and crosscutting relationships recognized in the field and Main pit at the Getchell mine. Ages for igneous and mineralizing events were determined through 40Ar/39Ar incremental heating analyses of 15 samples of biotite, K feldspar, sericite, and vein adularia. A thermal history for the area was also developed using K feldspar multiple diffusion domain results and age determinations on cogenetic minerals, which have different argon closure temperatures.

Том 42, Выпуск 5
Издание:Журнал Геология и геофизика, Новосибирск, 2001 г., 16 стр., УДК: 553.462:553.43
Язык(и)Русский
40Ar/39Ar геохронология магматических и метасоматических событий в Сорском Cu-Mo-порфировом рудном узле (Кузнецкий Алатау)

Проведено 40Аг/39Аг датирование (23 определения) магматических и рудно-метасоматических процессов в медно-молибденовом Соросом рудном районе. Установлено, что формированию крупномасштабного Сорского Cu-Mo-порфирового месторождения, связанного с развитием рудоносного порфирового комплекса, предшествовала длительная история развития многоимпульсного гранитоидного магматизма, отдельные импульсы которого сопровождались проявлением Cu-Mo-скарнового оруденения и калишпато-вых метасоматитов с рассеянным халькопиритом и молибденитом. Общий возрастной диапазон эндогенных событий в районе составляет 481—356 млн лет. Выявлено полиритмичное развитие рудоносного порфирового комплекса и связанных с ним рудно-метасоматических процессов. Основное промышленное Cu-Mo-порфировое оруденение Сорского месторождения связано с первым порфировым ритмом (389— 388 млн лет). Проявлению рудоносных порфиров и рудно-метасоматических образований предшествовало внедрение предрудных даек (405—402 млн лет). Развитие многоимпульсного магматизма и сопровождающей его разновозрастной рудной минерализации однотипного геохимического профиля (Си, Мо), с учетом низких значений (s'Sr/86Sr)0 и петрогеохимической близости магматитов, связывается с общей глубинной областью магмообразования.

Выпуск 90
Автор(ы):Robert P.Ilchik
Издание:Economic geology, 1995 г., 3 стр.
Язык(и)Английский
40Ar/39Ar, K/Ar, and fission track geochronology of sediment-hosted dessiminated gold deposits at Post-Betza, Carlin Trend, Northeastern Nevada - a discussion

Arehart et al. (1993) set out to date hydrothermal Au mineralization at the Post-Betze deposit in an attempt to place the formation of this deposit into a metallogenetic setting. Toward this end they have used many modern dating techniques including 40Ar/39Ar, K/Ar, and fission track geochronology. Based on the 39 measurements presented, they conclude that "based upon what we consider to be the most reliable" data this deposit formed at 117 Ma. This date is said to be consistent with similar ages for other intrusions in northeastern Nevada, and although one is not seen at the deposit, it is implied that a major nearby pluton is responsible for the formation of Post-Betze. By extrapolation, it is then suggested that Carlin-type Au systems are all of similar age, and thus, are the result of compressional tectonics operating prior to development of the current extensional environment. Because of the inescapable importance of the inferences and conclusions generated by the assignment of a 117 Ma age to the formation of the Post-Betze deposit, I would like to discuss the data and conclusions presented by Arehart et al. (1993).

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.

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.

2094.43