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Выпуск 29
Издание:Christian Weise Verlag Germany, Munchen, 99 стр., ISBN: 0945-8492
Язык(и)Немецкий
Die schonsten mineralien. Rublands

Wer Steine sammelt, möchte am liebsten den ganzen Planeten bereisen. Jeder Flecken Erde kann interessant sein. Für echte Mineralien- und Edelsteinsammler gibt es deshalb keine Grenzen, schon gar keine politischen. Sinnvoll ist vielleicht eine Grenze, die zwischen Kalkgesteinen und Graniten verläuft: Auf der einen Seite findet man ein paar kleine Calcite, jenseits der Grenze aber winken herrliche Topase, Berylle, Apatite und Turmaline. Doch weil wir Menschen sind, erfinden wir eben auch unsinnige Grenzen, zum Beispiel jene zwischen Ost und West. Auch wenn Deutschland nicht so extrem im „Westen" liegt wie Amerika, und Rußland nicht so extrem im ..Osten" wie China, so empfinden wir im deutsch-russischen Verhältnis doch eine Art Ost-West-Konflikt. Die Ursachen dafür sind jüngeren Datums, und wer zwei- bis dreihundert Jahre zurückblickt, entdeckt, daß die Sammlerherzen älterer Zeiten weit verzweigte und fruchtbare Freundschaftsbande geknüpft und gepflegt haben.

Westliche Fürsten und östliche Zaren tauschten nicht nur Waren, Kunst und Technik miteinander aus, sie förderten auch den Ost-West-Dialog der Wissenschaften. So schickten sie kistenweise Mineralien, Edelsteine und Fossilien hin und her, Sammler und Wissenschaftler pendelten zwischen Ost und West, zahlreiche Publikationen wurden ausgetauscht, es wurde lebhaft geforscht und diskutiert - alles in allem war es ein fruchtbarer Boden, auf dem auch mineralogisch sehr viel wachsen konnte.

Und wie sieht es heute aus? Was bringt uns das viel gepriesene Kommunikations-Zeitalter? Die Grenzen sind heute zwar wieder offener denn je, nicht nur elektronisch. Blickt man aber zurück in die Geschichte, scheint in der Ost-West-Mineralogie früher mehr los gewesen zu sein. Grund genug, erneut in Richtung Rußland zu blicken. Nicht misstrauisch, sondern mit der Freude, Reise- und Entdeckerlust, mit der dies z. B. im 19. Jahrhundert geschah. Das vorliegende extraLapis möge dazu beitragen: Noch nie gab es in deutscher Sprache einen so komprimierten Überblick über die russische Landesmineralogie, einen praxisorientierten Leitfaden zu diesem Sammelgebiet.

Und schließlich: Wenn wir als Sammler, ob in Ost oder West, die wir alle eine gemeinsame Liebe teilen - die kristallisierten Schätze der Erde - wenn wir es nicht schaffen, in Freundschaft alte Grenzen zu überwinden, wer soll es dann? Doch schauen wir erst einmal kurz nach Osten: Wo liegt Rußland überhaupt?

Автор(ы):Solle G.
Издание:Wiesbaden, 1956 г., 63 стр.
Язык(и)Немецкий
Die Watt-Fauna der unteren Klerfer Schichten von Greimerath

In der tiefsten Zone der unteren Klerfer Schichten (1956, Seite 85-89 beschrieben), in den untersten roten Grauwacken, fand sich eine Fauna, die hinsichtlich Reichtum, Artenzahl und Zusammensetzung, aber auch geologisch für die Klerfer Schichten einmalig ist. Wie durchweg in der Südost-Eifel, ist die Fauna marin. Aus mehrere Jahre hindurch fortgesetzter Ausbeutung gewannen wir ein reiches Material; die Fossilzone ist nunmehr vollständig abgebaut. Auffindung und Ausbeutung des Fundpunkts geschahen im Rahmen einer größeren Forschungsarbeit, deren Durchführung uns die Deutsche Forschungs-Gemeinschaft ermöglicht hatte. Für die weitreichende Hilfe sei der Deutschen Forschungs-Gemeinschaft der herzlichste Dank ausgesprochen!

Der Fundpunkt liegt unweit der Straße Wittlich-Hasborn (Bl. Hasborn), am Rand einer noch nicht fertiggestellten Autobahn-Ausfahrt, gegenüber der Straßenabzweigung nach Greimerath, knapp 300 m.s.

ТематикаПалеонтология
Выпуск 22
Автор(ы):Garlick S.R., Gromet L.P.
Издание:Journal metamorphic Geol, 2004 г., 18 стр.
Язык(и)Английский
Diffusion creep and partial melting in high temperature mylonitic gneisses, Hope Valley shear zone, New England Appalachians, USA

Field, petrographic, microstructural and isotopic studies of mylonitic gneisses and associated pegmatites along the Hope Valley shear zone in southern Rhode Island indicate that late Palaeozoic deformation (c. 275 Ma)in this zone occurred at very high temperatures (>650 C). High-energy cuspate ⁄ lobate phase boundary microstructures, a predominance of equant to sub-equant grains with low internal lattice strain, and mixed phase distributions indicate that diffusion creep was an important and possibly predominant deformation mechanism. Field and petrographic evidence are consistent with the presence of an intergranular melt phase during deformation, some of which collected into syntectonic pegmatites. Rb ⁄ Sr isotopic analyses of tightly sampled pegmatites and wall rocks confirm that the pegmatites were derived as partial melts of the immediately adjacent, isotopically heterogeneous mylonitic gneisses. The presence of syntectonic interstitial melts is inferred to have permitted a switch from dislocation creep to melt-enhanced diffusion creep as the dominant mechanism in these relatively coarse-grained mylonitic gneisses (200–500 lm syn-deformational grain size). A switch to diffusion creep would lead to significant weakening, and may explain why the Hope Valley shear zone evolved into a major regional tectonic boundary. This work identifies conditions under which diffusion creep operates in naturally deformed granitic rocks and illuminates the deformation processes involved in the development of a tectonic boundary between two distinct Late Proterozoic (Avalonian)basement terranes.

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.

Автор(ы):Ayalon A., Summer N.S.
Издание:Pergamon, 1995 г., 14 стр.
Язык(и)Английский
Dike intrusion into unconsolidated sandstone and the development of quartzite contact zones

Shallow, near-surface magma emplacement into a porous, unlithified sandstone occurred by forceful dike dilation and was accompanied by a localized hydrothermal event. Petrographic fabric, authigenic mineralogy and petrophysical data, grade smoothly through the quartzite contact zone outward into the friable Inmar sandstone of Makhtesh Ramon, Israel. Quartz grain deformation, fracturing and rehealing of grains, and pressure solution constitute overwhelming evidence of a compressive environment adjacent to dike margins, albeit with temperatures and pressures insufficient to fully recrystallize detrital grains. Dikes were accommodated primarily by the repacking of the sandstone with both brittle and elastic grain interaction. Post emplacement heating together with elastic compressive stress dissipation, lead to fracture healing and pressure solution. The occasional columnar-jointing must be related to thermal contraction of the quartzite during later cooling and resulting mode I cracks. The alteration of both contact zone and dike material occurred via a transitory and confined hydrothermal seepage up dike margins. Elsewhere around the world highly altered intrusions bordered by indurated sometimes uniformly jointed sediments, may also be the result of forceful magma emplacement and hydrothermal alteration at near-surface levels.


Автор(ы):Pim K.
Издание:New York, 2019 г., 371 стр., ISBN: 978-1-61519-519-0
Язык(и)Английский
Dinosaurs. The grand tour. Evrything worth knowing about dinosaurs from Aardonyx to Zuniceratops / Динозавры. Гранд тур. Все, что стоит знать о динозаврах от Aardonyx до Zuniceratops

We live in a golden age of paleontological discovery—on average, we fi nd one new dinosaur species per week. The most fascinating among them take their place in this updated edition of Dinosaurs—The Grand Tour, from Aardonyx, a lumbering beast that formed a link between two- and four-legged dinosaurs, to Zuniceratops, who boasted a deadly pair of horns.

Here, you’ll fi nd everything worth knowing about every dinosaur worth learning about—more than three hundred in all. At-a-glance sidebars put each dinosaur’s diet, size, and where they roamed at your fi ngertips. Stories of harrowing expeditions conjure the thrills of history’s most famous dinosaur hunters. Highlights from recent research reveal what’s new in paleontology today, including scientists’ evolving ideas of what dinosaurs actually looked like. (Hint: They were more colorful—and feathery!—than we thought before.) And illustrations on virtually every page bring these prehistoric creatures to life in all their glory.

Plus, renowned paleontologist Jack Horner contributes “fi eld notes” to help readers set out on their own expeditions—from seeking fossilized footprints at his recommended sites to planning a cross-country road trip using his list of top North American dinosaurs as a map. You’ll learn what it’s like to be part of the most sensational dino-discoveries ever—and maybe make some of your own!

Выпуск 24
Автор(ы):Keewook Y., Wintsch R.P.
Издание:Journal of Structural Geology, 2002 г., 15 стр.
Язык(и)Английский
Dissolution and replacement creep: a significant deformation mechanism in mid-crustal rocks

Zoning patterns and zoning truncations in metamorphic minerals in a granodioritic orthogneiss indicate that strain and S-C fabrics in these rocks were produced by dissolution, precipitation, and replacement processes, even at epidote-amphibolite fades metamorphic conditions. The metamorphic fabric is defined by alternating layers and folia dominated by quartz, feldspars, and biotite + epidote. Zoning patterns in most metamorphic plagioclase, orthoclase, epidote, and sphene are truncated at boundaries normal to the shortening direction, suggesting dissolution. Interfaces of relict igneous orthoclase phenocrysts that face the shortening direction are embayed and replaced by biotite, epidote, and myrmekitic intergrowths of plagioclase and quartz. Metamorphic plagioclase grains are also replaced by epidote. We interpret these microstractures to reflect strain-enhanced dissolution. The cores of many grains show asymmetric overgrowths with at least two generations of beards, all oriented on the ends of grains that face the extension direction. We interpret these textures to reflect precipitation of components dissolved by deformation-enhanced dissolution. While biotite and quartz probably deformed by dislocation creep, the overall deformation was accommodated by dissolution perpendicular to the shortening direction, and precipitation parallel to it. These chemical processes must have been activated at lower stresses than the dislocation creep predicted from extrapolations of data from experiments in dry rocks. Thus wet crust is likely to be weaker than calculated from these experimental studies

Выпуск 76
Автор(ы):Almeras Y., Peybernes B.
Издание:Lyon, 1979 г., 112 стр.
Язык(и)Французский
Documents des laboratoires de geologie de la faculte des sciences de Lyon. Les brachiopodes du dogger des pyrenees Navarro-Languedociennes

Au cours de la revision stratigraphique du Dogger des Pyrenees Navarro-Languedo- ciennes (Peybernbs, 1976), des gisements de brachiopodes ont ete signals tant dans les Pyrenees fran- gaises (Corbiferes essentiellement) qu'espagnoles. Ces brachiopodes ddtermines (Y. Almiras) et replaces dans les coupes stratigraphiques (PeybernSs, 1976) sont ici etudies par les methodes biometriques classi- ques (dynamique des populations, ontogenese) et &. l'aide des coupes seriees (caracteres internes). Grace a nos connaissances sur la biostratigraphie de ces memes especes de brachiopodes dans d'autres regions, nous avons pu confirmer ou prdciser la datation encore incertaine de plusieurs niveaux du Dogger. <...>

Автор(ы):Yang Chang-Shu
Издание:Instituut voor Aardwetenschappen der Rijksuniversiteit te Utrecht, 1989 г., 160 стр., ISBN: 90-71577-13-9
Язык(и)Английский
Dynamics and sedimentary facies analysis of clastic tidal deposits

One of the most important dynamic processes in the ocean is that of tidal movement. The tides obtain their energy from the earth's rotation. Most of this energy is received in the major ocean basins, and from there transmitted into shallow waters. It is in these shallow waters that tidal energy is dissipated, in part by eroding and transporting sediments, resulting in very active sedimentary processes in the shelf and coastal areas.

Research in clastic tidal deposits has accumulated large-amount of data on tidal processes and their products. In present-day tide-swept shelves large-scale tidal sandbodies with various bedforms has been a subject of extensive research, which mainly focussed on the southern bight of the North Sea (van Veen, 1935; Jones, Kain & Stride, 1965; Houbolt, 1968; Stride, 1970; Caston & Stride, 1970,1973; McCave, 197.1; Terwindt, 1971,1973; Cas-ton, 1972; Johnson et al., 1981; Kenyon et al., 1981; Langhorne, 1982; McCave & Lan-ghorne, 1982; Nio & Nelson, 1982; Stride, 1982; de Boer, van Gelder & Nio, 1988), the English Channel and the French Atlantic shelf (Berne et al., 1986; Berne et al., 1988; Turcq et al, 1986) and the North American Atlantic shelf (Swift et al., 1972,1979,1981; Milliman etal., 1972; Sheridan etal, 1974;Knebel&Folger, 1976,Knebel, 1981; Swift & Field, 1981).

In estuaries and other inshore tidal basins, genesis, geometry, distribution pattern, dynamic behaviour and internal sedimentary structures of tidal bedforms have been studied intensively in the Netherlands (Boersma, 1969; Terwindt, 1970,1981; de Raaf & Boersma, 1971; Boersma & Terwindt, 1981; Kohsiek & Terwindt, 1981; van den Berg, 1982, 1984, 1987; Terwindt & Brouwer, 1986; de Boer, van Gelder & Nio, 1988), U.K. (Langhorne, 1973; Allen & Friend, 1976; Elliott & Gardiner, 1981), France (Tastet et al, 1986), United States (Boothroyd & Hubbard, 1975; Bokuniewicz, et al, 1977), Canada (Swift et al, 1966; d'Anglejan, 1971; Dalrymple et al, 1975,1978; Dalrymple, 1984) and other countries. Most of the studies were concentrated in intertidal areas. The subtidal deposits received less attention due to the difficulties in field observations. Preservation potential of subtidal deposits, however, is much higher. As a consequence subtidal deposits will occur more often in the geological record. It is from the detailed study of the subtidal deposits in the construction pits of the Oosterschelde, SW Netherlands that distinct diagnostic criteria for recognizing tide-dominated deposits were developed (Visser, 1980; Siegenthaler, 1982; van den Berg, 1982; Nio et al., 1983; de Mowbray & Visser, 1984; Yang & Nio, 1985). <...>

Издание:Russian Geology and Geophysics, 2011 г., 15 стр.
Язык(и)Английский
Early–Middle Ordovician nappe tectonics of the junction between the Kokchetav HP-UHP metamorphic belt and the Stepnyak paleoisland arc

The North Kokchetav tectonic zone is located between the Kokchetav HP-UHP metamorphic belt and the Stepnyak zone of Ordovician island arc and oceanic complexes. The Kokchetav zone is a collage of nappes (thrust sheets) that consist of basement gneiss and sedimentary rocks of the Kokchetav microcontinent, granite gneiss, mica schists with eclogite blocks, the Shchuch’e ophiolite, Middle Proterozoic felsic volcanics, and Arenigian siliceous-terrigenous sediments with olistostromes. The latter are of gravity-sliding origin and their clastic material includes quartz-muscovite and quartz-garnet-muscovite schists, gneiss, dolomite, and amphibolite. The sheet boundaries are marked by mylonite and Early Ordovician mica schists (40Ar/39Ar ages of syntectonic muscovite are 489–469 Ma). The North Kokchetav collage of compositionally diverse thrust sheets can be interpreted as a collisional zone. According to geological evidence, tectonic activity in the zone lasted as late as the Middle Ordovician. Syncollisional thrusting in the North Kokchetav zone was coeval with the latest dynamic metamorphic event in the history of the Kokchetav belt. All events of retrograde metamorphism and exhumation of HP and UHP rocks in the belt have Cambrian ages, i.e., the rocks had been exhumed prior to the Early–Middle Ordovician collisions and the related orogeny.

1967.41