Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке

Автор(ы):Щетников А.А.
Издание:2008 г., 5 стр., УДК: 551.248.2 (571.54)
Язык(и)Русский
Проявление гобийского механизма горообразования в Байкальской рифтовой зоне (на примере Тункинского рифта)

Остаточно-горстовый (байкальский, по [1, 2]) механизм горообразования реализуется в процессе переукладки блоков приповерхностных частей земной коры при утонении литосферы под влиянием ее горизонтального растяжения. Это определяет дифференцированные погружения тектонических блоков различных иерархических уровней, отделяющихся от продолжающих воздыматься горных поднятий, и расширение благодаря этому межгорных впадин. Вместе с тем данный процесс нередко осложняется положительными инверсионными тектоническими подвижками во внутри-рифтовых сооружениях. На фоне общих погружений блоков докайнозойского фундамента грабенов в них наблюдаются локальные воздымания, выраженные в рельефе обращенными морфоструктура-ми. Они разнообразно представлены во впадинах Байкальской рифтовой зоны.

Наиболее масштабно инверсионный морфотектогенез проявился в ее Тункинской секции. Наличие здесь инверсионных тектонических движений фиксировали многие исследователи [1–6]. Одним из первых на это обратил внимание Н. А. Флоренсов [1], который отметил, что отчетливая складчатость отложений на краях впадины принадлежит явлениям регионального порядка, выходящего за рамки одной Тункинской впадины, и свидетельствует о компрессии, не совместимой с обстановкой рифта. Осложняющие направленное развитие Тункинского рифта локальные тектонические инверсии имеют различные механизмы формирования [3], однако ведущая роль принадлежит проявлению элементов гобийского орогенеза. Характеристике этого процесса в регионе и посвящена настоящая работа.

Том 28, Выпуск 4
Издание:Journal Geotectonics, 1995 г., 11 стр.
Язык(и)Английский
Romanche fracture zone: Structure, evolution, and geodynamics / Зона разлома Романш: структура, эволюция и геодинамика

This work is based on survey data from the 13th and 16th cruises of the R/V Akademik Nikolai Strakhov. The tectonic structure of the Romanche fracture zone in the Equatorial Atlantic is considered. Based on its dynamics, kinematics and historical evolution, the zone does not seem to be a uniform structure. Its segments are of different age and evolved according to different dynamic and kinematic laws. The fracture zone is not continuous in space: deformations complicating it migrate both along and a cross its strike, creating new fracture zones with somewhat different orientation. Three geodynamic systems are recognized within the fracture zone, namely Rom 1, Rom 2 and Rom 3.   In the eastern junction of the rift and the Romanche fracture zone, the rift valley jumps northward with simultaneous prograding. A "dry" spreading mode is pronounced in the region.

Том 20, Выпуск 7
Автор(ы):Druguet E., Hutton D.H.W.
Издание:Pergamon, 1998 г., 12 стр.
Язык(и)Английский
Syntectonic anatexis and magmatism in a mid-crustal transpressional shear zone: an example from the Hercynian rocks of the eastern Pyrenees

Hercynian metamorphism and magmatism in the Cap de Creus peninsula (eastern Pyrenees) occurred contemporaneously with non-coaxial deformation in a transpressive regime. An example of this has been taken from a migmatite complex in the northern coast. The studied area is formed by partially melted sil-limanite schists together with two different suites of igneous rocks: a calc-alkaline magmatic sequence, consisting of small granitoid bodies, and later peraluminous leucogranites and pegmatites. All these rocks occur within a NE-SW- to E-W-trending sub-vertical high-strain zone, where a first schistosity is tightly folded and transposed. The relations between folds and crenulation cleavage in the metasediments and deformational fabrics in the granitoids and migmatites provide good evidence for the penecontemporaneity of deformational processes, magmatism and migmatization. Furthermore, the analysis of cross-cutting relationships between different granitoids as well as the observation of their different degrees of deformation verifies that magmatism in this area took place as synkinematic consecutive intrusions from the more basic magmas to the peraluminous acid dykes.

Выпуск 261
Автор(ы):Mercier J.-C.C., Ross.J.V., Xu Y.
Издание:Journal Tectonophysics, 1996 г., 15 стр.
Язык(и)Английский
Diffusion creep in the upper mantle an example from the Tanlu Fault, northeastern China

Ultramafic xenoliths in Neogene alkalic basalts emplaced within the Yitong graben associated with the Tanlu Fault, northeastern China, are mostly variably deformed lherzolites, werhlites and minor pyroxenites. Glass, rich in Si02, A1203, K20 and Na20, is optically recognised as occurring in veins, triple-point grain junctions, and patches in werhlite and some lherzolite samples. Textural observations also suggest that the glass (melt) was involved in the deformation, and was present prior to sampling by the host basalt. Electron microprobe scans for these glass elements indicate that glass is not only present at triple-point grain junctions and in veins, but also completely along some planar grain boundaries.

Выпуск 168
Автор(ы):He Y., Sun M., Xia X., Zhao G.
Издание:Precambrian research, 2009 г., 10 стр.
Язык(и)Английский
SHRIMP and LA-ICP-MS zircon geochronology of the Xiong’er volcanic rocks Implications for the Paleo-Mesoproterozoic evolution of the southern margin of the North China Craton

The Paleo-Mesoproterozoic Xiong’er volcanic rocks along the southern margin of the North China Craton are lithologically and geochemically similar to those formed in subduction-related, continental margin volcanic arcs. The volcanic rocks are primarily composed of basaltic andesites and andesites, with minor dacites and dacitic rhyolites. Traditionally, the Xiong’er volcanic rocks have been divided from lower to upper into the Xushan, Jidanping and Majiahe Formations, but the ages of volcanic rocks in these formations have not been well constrained, which has hindered further understanding the tectonic significance oftheXiong’er volcanicbeltatthe southern marginofthe NorthChina Craton.

Том 32, Выпуск 6
Автор(ы):Герасимов П.А.
Язык(и)Русский
Кимериджские отложения Подмосковного края

В статье изложены результаты проведенного автором изучения кимериджских отложений Подмосковного края, до последнего времени принадлежавших к наименее известным мезозойским осадкам этой территории. Указывается распространение нижне- и верхнекимериджских отложений, отмечаются их фациальные особенности, дается фаунистическая и литологическая характеристики. Описывается новая для Подмосковного края, вообще редкая порода — спонголит.


Выпуск 136
Издание:Journal Marine Geology, 1997 г., 13 стр.
Язык(и)Английский
Stratigraphic numerical modelling of a carbonate platform on the Romanche transverse ridge, equatorial Atlantic

The Romanche transverse ridge (equatorial Atlantic) is located in the northern flank of the fracture zone, opposite the eastern ridge-transform intersection (RTI). It constitutes a major positive topographic anomaly that reaches a height of over 4 km above the level predicted by the thermal subsidence curve. A series of E-W aligned peaks, located on the crest of the transverse ridge, were at sea level during early and middle Miocene times; they are presently capped by a ~300 m thick, shallow-water carbonate platform that grew on a subsiding oceanic crust basement surface flattened by erosion at sea level. These structures are now about 1 km below sea level. High resolution seismic reflection surveys and multibeam morphobathymetry as well as study of samples recovered from the carbonate platform allowed a reconstruction of the paleoenvironment and of the vertical movements of the peaks starting from the lower Miocene. Ages derived from microfossils suggest that the base of the carbonate platform dates from 17-25 m.y. ago and the sinking of the platform started between 18 and 13 m.y. ago. These data were included in a numerical simulation model that takes into account thermal and tectonic subsidence, growth potential of the carbonates, subaerial and submarine erosion rates and Mio-Pliocene absolute sea level fluctuations. The results outline the subsidence history of the Romanche transverse ridge and suggest post-Miocene subsidence faster than that predicted by the thermal cooling model.

 

Выпуск 378
Автор(ы):Shimamoto T., Uehara S.
Издание:Journal Tectonophysics, 2004 г., 13 стр.
Язык(и)Английский
Gas permeability evolution of cataclasite and fault gouge in triaxial compression and implications for changes in fault-zone permeability structure through the earthquake cycle

Эволюция газопроницаемости катаклазита и разломной впадины при трехосном сжатии и влияние на изменения структуры проницаемости зоны разлома в течение цикла землетрясений

We report the results of permeability measurements of fault gouge and tonalitic cataclasite from the fault zone of the Median Tectonic Line, Ohshika, central Japan, carried out during triaxial compression tests. The experiments revealed marked effects of deformation on the permeability of the specimens. Permeability of fault gouge decreases rapidly by about two orders of magnitude during initial loading and continues to decrease slowly during further inelastic deformation.

Автор(ы):Martin-Closas C., Salas C.
Издание:Publicaciobes Universidat de Barcelona, Barcelona, 1995 г., 147 стр.
Язык(и)Испанский
El cretacico inferior del Nordeste de Iberia

On the occasion of the III Colloquium on the Cretaceous of Spain, which took place in More-lla on the 6th, 7th and 8th September 1991 sponsored by the Spanish Group of Mesozoic, there were two field trips to illústrate the present knowledge of the Lower Cretaceous of Northeastern Iberia. These excursions are the object of the present guide-book. In the period passed between when this guide-book was written and its final publication, new results were published which represent a significant increase in our previous knowledge. These publications in international journals, which are referenced at the end of the foreword, together with the figure captions of this guide-book, which have been translated in English, will help the English reader to obtain the information necessary to understand the Lower Cretaceous of Northeastern Iberia.

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