Fossile Riffe als Klimazeugen in Australien

Summary First true coral reefs in Australia appear in the Silurian of northern Queensland. The reef belt then advances to the south and reaches its maximum in the Middle Devonian. In the Upper Devonian and Lower Carboniferous reef-building activity is again restricted to the north. Reefs are unknown from the Upper Carboniferous until the middle Tertiary. The southern limit of the reef belt advances along the west coast, possibly since the Miocene and reaches its extreme southerly position (32° S. lat.) in the late Pleistocene, probably the last Interglacial. Since then it has moved northward to 29° N. lat. In the east the Great Barrier Reef reaches southward as far as 24° N. lat. and no more southerly reefs of Pleistocene or Recent age are known. The significance of these facts for the theory of continental drift is difficult to assess. The Pleospongia (Archaeocyathinae) of the Cambrian are not reef-builders and their distribution could be satisfactorily explained by assuming that they were restricted to the temperate belts in both hemispheres. Conditions in the Middle Devonian with their extraordinary expansion of reef-building organisms require special explanation, but before a shift of the Australian continent relative to the climatic belts is accepted, it is neccessary to study the very irregular course of the limits of the present reef belt. Comparing marine faunas of similar latitudes today one may encounter differences perhaps not less profound than those between Devonian faunas in comparable belts.     

Prediction of the present-day stress field in the Australian continental crust using 3D geomechanical–numerical models

The Australian continent has an enigmatic present-day stress pattern with considerable regional variability in maximum horizontal stress (S_Hmax) orientations. Previous attempts to estimate the Australian S_Hmax orientation with geomechanical–numerical models indicate that plate boundary forces provide the major controls on the contemporary stress orientations. However, these models do not satisfactorily predict the observed stress orientation in major basins throughout eastern Australia, where the knowledge of the present-day crustal stresses is of vital importance for development and management of different types of geo-reservoirs. In addition, a new comprehensive stress-data compilation in Australia, which contains 2150 data records and is the key dataset for model calibration, provides motivation to construct a new geomechanical–numerical model for Australia. Herein, we present a 3D geomechanical–numerical model that predicts both the S_Hmax orientation and the relative stress magnitudes throughout the Australian continent. Our best-fit model, with mean absolute deviation of 15°, is in good agreement with observed S_Hmax orientations and the stress regime in most areas, and shows a much better fit in areas where the stress pattern was unable to be predicted by previous published attempts. Interestingly, the best-fit model requires a significant push from the western boundary of Australian continental model, which is possible supporting evidence for the east–west-oriented mantle drag postulated by state-of-the-art global convection models, or may be generated by the excess of gravitational potential energy from Tibetan Plateau, transferred through the Indo-Australian Plate. Hence, our modelling results provide a good first-order prediction of the stress field for areas where no stress information is currently available and can be used to derive initial and boundary conditions for local and reservoir-scale 3D geomechanical models across Australia.     

The 1800–1100 Ma tectonic evolution of Australia

This paper presents a plate tectonic model for the evolution of the Australian continent between ca. 1800 and 1100 Ma. Between ca. 1800 and 1600 Ma episodic orogenesis occurred along the southern margin of the continent above a north-dipping subduction system. During this interval multiple orogenic events occurred. The West Australian Craton collided with the North Australian Craton (ca. 1790–1770 Ma), the Archaean nucleus of the Gawler Craton amalgamated with the North Australian Craton (ca. 1740–1690 Ma), and numerous smaller terranes accreted along the western Gawler Craton and the southern Arunta Inlier (ca. 1690–1640 Ma). The pattern of accretion suggests southward migration of the plate margin, which occurred due to a combination of slab rollback and back stepping of a subduction system behind the accreted continental blocks. Coeval with subduction a series of continental back-arc basins formed in the interior of the North Australian Craton and parts of the South Australian Craton, which were attached to the North Australian Craton prior to 1500 Ma. Extension of the North Australian Craton led to the opening of an oceanic basin along the eastern margin of the continent at ca. 1660 Ma. Continuing divergence was accommodated by oceanic spreading whereas the continental basins thermally subsided resulting in the development of sag-phase basins throughout the North Australian Craton. This oceanic basin was subsequently consumed during convergence, which ultimately led to development of a ca. 1600–1500 Ma orogenic belt along the eastern margin of Proterozoic Australia. Between ca. 1470 and 1100 Ma, the South Australian Craton, consisting of the Curnamona Province and the Gawler Craton rifted from the North Australian Craton and was re-attached in its present configuration during episodic ca. 1330–1100 Ma orogenesis, which is preserved in the Albany-Fraser Belt and the Musgrave Block.     

Bonding in eight ordered clinopyroxenes isostructural with diopside

Bond distances and angles in isostructural, ordered clinopyroxenes are compared for eight compositions, based on five new and three published crystal-structure refinements from X-ray diffraction data. Unit-cell parameters and configuration of the silicate chains are directly correlated with cation composition and distribution in the M2 and M1 sites.Publication authorized by the Director, U. S. Geological Survey.Our thanks go to D. B. Stewart, C. Milton, and C. S. Ross, U. S. Geological Survey, who supplied crystals of the minerals, to D. B. Stewart for synthesis of iron spodumene, to Dr. L. Fuchs, Argonne National Laboratory, for synthesis of ureyite, and to Dr. B. Mason, U. S. National Museum, who transmitted the ureyite crystals.     

Tertiary evolution of the Eastern Indonesia Collision Complex

Eastern Indonesia is the zone of interaction between three converging megaplates: Eurasia, the Pacific and Indo-Australia. The geological basis for interpretations of the Tertiary tectonic evolution of Eastern Indonesia is reviewed, and a series of plate tectonic reconstructions for this region at 5 million year intervals covering the last 35 million years is presented.The oldest reconstruction predates the onset of regional collisional deformation. At this time a simple plate configuration is interpreted, consisting of the northward-moving Australian continent approaching an approximately E–W oriented, southward-facing subduction zone extending from the southern margin of the Eurasian continent eastwards into the Pacific oceanic domain. Beginning at about 30 Ma the Australian continental margin commenced collision with the subduction zone along its entire palinspastically-restored northern margin, from Sulawesi in the west to Papua New Guinea in the east. From this time until ca 24 Ma, the Australian continent indented the former arc trend, with the northward convergence of Australia absorbed at the palaeo-northern boundary of the Philippine Sea Plate (the present-day Palau-Kyushu Ridge).At ca 24 Ma the present-day pattern of oblique convergence between the northern margin of Australia and the Philippine Sea Plate began to develop. At about this time a large portion of the Palaeogene colliding volcanic arc (the future eastern Philippines) began to detach from the northern continental margin by left-lateral strike slip. From ca 18 Ma oblique southward-directed subduction commenced at the Maramuni Arc in northern New Guinea. At ca 12 Ma the Sorong Fault Zone strike-slip system developed, effectively separating the Philippines from the Indonesian tectonic domain. The Sorong Fault Zone became inactive at ca 6 Ma, since which time the tectonics of eastern Indonesia has been dominated by the anticlockwise rotation of the Bird’s Head structural block by some 30–40°.Contemporaneously with post-18 Ma tectonism, the Banda Arc subduction–collision system developed off the northwestern margin of the Australian continent. Convergence between Indo-Australia and Eurasia was accommodated initially by northward subduction of the Indian Ocean, and subsequently, since ca 8 Ma, by the development of a second phase of arc-continent collision around the former passive continental margin of NW Australia.     

Geometrie und Geologie von Kreuzschichtungs-Körpern

Zusammenfassung Im Raster-Meßverfahren werden Kreuzschichtungs-Gefüge objektiv und vollständig erfaßt. Die Gefüge-Axen dienen zur geometrischen Beschreibung der angeschnittenen Körper. Aus ihrem Profil-Anschnitt wird die räumliche Ablagerungsform und Anordnung der Kreuzschichtungs-Körper rekonstruiert. Es ist danach möglich, fossile Kreuzschichtungs-Gefüge unter sich und mit rezenten Schüttungskörpern exakt zu vergleichen. Kreuzschichtungs-Körper in Flußablagerungen und in Gezeitenablagerungen unterscheiden sich; sie zeigen also Bildungsbedingungen an. Es ergeben sich Ansätze für eine natürliche Gliederung der Kreuzschichtung.Diese Untersuchungen an Kreuzschichtungs-Gefügen waren Gegenstand einer Doktorarbeit. Sie entstand 1954–56 am Geologischen Institut in Bonn auf Anregung von Prof. Dr. R.Brinkmann. Zur Arbeit beigetragen haben die Herren Prof. Dr. G.Wagner, Prof. Dr. P.Woldstedt, Prof. Dr. J.Frechen, Prof. Dr. W.Bierther, Prof. Dr. E.Seibold, Doz. Dr. R.Hoeppener, Dr. W.Niehoff, Dr. J.Hülsemann, Dr. G.-H.Tischer und mein Vater. Die Studienstiftung des deutschen Volkes förderte die Arbeit.     

Common features of the tectonosphere deep structure in the Western Pacific Margins (Northeast Asia Region and Australia)

This paper analyses the spatial distributions of gravity sources and density contrast of geological media between the centers of mass of density heterogeneities and surfaces of some layers, which is reflected by the values of parameter μ_z, in the Northeast Asia Region and Australia. Statistical images of complex distributions of density heterogeneities are generally consistent with the shallowest tectonic structures, wave velocity, and electric anomalies. The correlation of μ_z minimums with high heat flow suggests melted magmas beneath the crust base and in the asthenosphere. In the lower crust layer, large μ_z maximums correlate with major continental megaelements, which are divided by extended linear μ_z minimums, high conductivity anomalies, and Vp/Vs maximums marking zones of lower viscosity. Deep boundaries and a thickness of lithospheric plates and asthenosphere lenses have been defined in the Northeast Asia Region. In Australia, two roughly NS-striking low-viscosity zones crossing the continent reflect the deep setting of the Lasseter (in the west) and the Tasman (in the east) lines. These zones are displayed in a wide depth range (15–120 km) and are confined to the Archean–Proterozoic and Proterozoic–Phanerozoic boundaries in the Australian lithosphere. Statistical gravity models derived without external (relatively to gravity) geological and geophysical information prove the multilayered tectonosphere structure of both continents and the similar deep structure features of their margins.     

Krokodile als Klimazeugen

Zusammenfassung Aus den wenigen bekannten Daten über Lebensweise und Verbreitung rezenter Krokodile wird versucht, Mindesttemperaturen für das Biotop fossiler Krokodile zu ermitteln. Die gefundenen Werte (+10 C und mehr für die Durchschnittstemperatur des kältesten Monats) sind im Vergleich mit bekannten PaläoTemperaturen durchaus wahrscheinlich.

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Summary Recent crocodiles are distributed up to the 10 or 15 C isothermal line of January/ N. Hemisphere or July/S. Hemisphere, see fig. 1. The analysis of the distribution of tertiary crocodiles in Europe indicates that probably recent and fossil crocodiles are restricted in their geographical range by the same temperature limits.

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Résumé Une analyse de la distribution des crocodiles tertiaires en Europe montre que probablement cettes formes fossiles de mÊme que les récents vivaient en régions oÚ les temperatures étaient au mois le plus froid au-dessus de 10 ou 15 degrés (v. Fig. 1).

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Erweiterte Fassung eines auf Anregung von Herrn Prof. Dr. H.Tobien auf der Jahrestagung der Geol. Ver. in Köln 1964 gehaltenen Vortrags.

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Zu danken habe ich Herrn Prof.Brinkmann, Bonn, und Herrn Prof. v.Gaertner, Hannover, für Diskussionshinweise (bezüglich des Biotops von Krokodilen und lokaler Temperaturverhältnisse), die in obigen Ausführungen berücksichtigt wurden; ferner danke ich Herrn Dipl.-Biol.Hemmer, Mainz, für kollegiale Beratung in zoologischen Fragen.     

Le massif ultrabasique des Beni Bouchera (Rif Interne,Maroc): Etude des péridotites de haute température et de haute pression,et des pyroxénolites, à grenat ou sans grenat,qui leur sont associées

The ultrabasic rocks which form the Beni Bouchera massif are schistose and folded isoclinally. They outcrop at the center of a late formed anticline under a series of granulite facies precambrian or lower paleozoic rocks. The ultrabasic rocks appear to have been in situ during the major structural development of the series and were emplaced at the time of metamorphism. The massif itself is essentially a peridotite, apparently layered, which contains pyroxenite bands (about 3% of the total volume of the massif). The peridotites are olivinerich containing two aluminous pyroxenes and spinel. The pyroxenites are however quite varied. They are frequently banded themselves and in several centimeters thickness can vary from enstatite rocks at the exterior of the layers to garnet clinopyroxenites at the center with websterite and garnet websterite as intermediate rock type. They are also present as monofacies bands of enstatite or garnet clinopyroxenite rock. Occasionally the minerals in these bands show exsolution features.Thirty six new rock and mineral chemical analyses are presented here. An attempt is made to use these data correlated with abundant bibliographic material in order to evaluate the conditions of formation of the rock types. The temperature range is estimated to be 1100–1200° C, pressures between 15 and 20 kbs in the latest facies and 1400°C and 25 kbs for a primary phase represented by the pyroxenites showing marked exsolution features. Various arguments lead to the conclusion that the pyroxenite bands crystallized from a liquid which was in equilibrium with the solid lherzolite.One sees in the Beni Bouchera the results of anatectic melting of an aluminous peridotite which originated in the upper mantle. This partial fusion was caused by the adiabatic upward movement of the mantle material toward the lower crust where tangential tectonic movements emplaced it as a solidified mass in an orogenic root zone under granulite facies conditions.

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Equipe de recherches associée au C.N.R.S.: Pétrogenèse des roches éruptives et métamorphiques

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Plusieurs missions sur le terrain ont été effectuées avec le concours du Service Géologique du Maroc et grâce, particulièrement, à G. Choubert, M. Diouri, Y. Ennadifi et A. FaureMuret. Les études pétrographiques ont été poursuivies à la Sorbonne sous la direction de J. Jung et de J. Ravier. Une aide inestimable m'a été apportée par M. J. O'Hara pour la rédaction de ce mémoire. A divers titres j'ai largement bénéficié des conseils et critiques de B. Azambre, F. Conquere, M. Durand-Delga, M. Fonteilles, J. R. Kienast, B. Velde, D. Velde et J. C. Vilminot     

The oldest fossil faunas of South Australia

A critical review of earlier references to Precambrian fossils in South Australia shows that Radiolaria could be present but that other animal remains listed or described by earlier authors have been wrongly interpreted. There is no evidence for the presence of Arthropods in this material.The fauna described bySprigg from the early Cambrian sandstone and quartzite of Ediacara consists not only of Medusae. Recent studies have shown that it includes specimens resembling the types ofPteridinium andRangea from the Nama Series of Southwest Africa. They are now considered as related to living Pennatulacea. In addition, there are present the annelidSpriggina, possibly Siphonophora, and at least two entirely new forms of invertebrates.This assemblage is followed by a sequence of undoubted Lower Cambrian faunas from the lowest Archaeocyatha horizon up to theProtolenus-Zone. The Ediacara fauna which consists only of soft-bodied animals is entirely unlike any known Cambrian fauna. This fact supports the view that it is Precambrian.     

Talksynthesen im Hinblick auf semisalinare Bedingungen

Zusammenfassung Vor einigen Jahren wurde Talk als Begleitmineral in Salzlagerstän erstmalig gefunden, und zwar in den amerikanischen Salzlagerstätten in Texas und Neu-Mexiko (Balley), in dem englischen Kalisalzvorkommen bei Eskdale in Ost-Vorkshire (Stewart), sowie im Hallstätter Salzberg des alpinen Haselgebirges (Mayrhofer undSChauberger). Auch in Deutschland wurde kürzlich bei der Erdgasbohrung Frenswegen 3 im Emsland in den oberen Lagen des Zechsteinanhydritprofils ein talkantiges Mineral identifiziert (Füchtbauer undGold-Schmidt). Die drei erstgenannten Talkvorkommen zeigen in der Art des Auftretens wesentliche gemeinsame Züge, aus denen man schließen kann, daß sie in der Lagerstätte selber entstanden sind, nicht aber dadurch, daß Talk als Verunreinigung in die Lagerstätte gelangte. Bei näherer Betrachtung bietet sich die Auffassung an, daß der Talk semisalinar (Leonhardt undBerdesinski) gebildet wurde, durch die Einwirkung Mg²⁺-haltiger Reaktionslösungen auf SiO₂-haltige Substanzen, die durch Zuflüsse usw. in die Lagerstätte gelangten. Von diesen Überlegungen ausgehend war zu prüfen, ob sich Talk wirklich bildet bei der Einwirkung von Mg-Laugen auf SiO₂, und zwar bei milden Metamorphosebedingungen, d. h. bei möglichst niedriger Temperatur und niedrigem Druck, entsprechend den wahrscheinlichen Bedingungen in den Salzlagerstätten. Bei den Versuchen wurden MgCl₂-haltige und Carnallit-Lösungen verwandt und stark gealtertes SiO₂-Gel, Quarz feinkristallin, Na₂Si₂O₅ · 2H₂O und Wasserglas als Bodenkörper gewählt. Die Reaktionsprodukte wurden vorwiegend röntgenographisch nach dem Debye-Verfahren untersucht und dann mit, abnehmendem Bildungsgrad in die 3 Gruppen: 1. Talk, 2. Talkprodukt, 3. Hinbildung zum Talk bzw. nur geringe Umbildung eingestuft.Um weitere, differenziertere Aussagen machen zu können, wurden typische Proben mit einer Talkvergleichssubstanz nach der Guiniermethode mit zweigeteilter Kamera untersucht; es wurden auch chemische Analysen und Anfärbtests durchgeführt und von bestimmten Synthesebildungen die mittleren Brechungsindizes bestimmt.Versuche mit SiO₂-Gel als Bodenkörper führten bei einer Reaktionstemperatur von 150° C noch zu guten Talkprodukten. Die 100° C-Versuche sind noch nicht abgeschlossen; ihre Ergebnisse bleiben einer späteren Veröffentlichung vorbehalten. Aber ein Versuch ergab bereits eine Hinbildung zum Talk. Die Synthesen mit Quarz als Bodenkörper erforderten wesentlich längere Reaktionszeiten, führten aber auch bis herab zu 150° C zur Hinbildung zum Talk. Bei Wasserglas (gallertig-dickflüssig) und Na₂Si₂O₅ · 2 H₂O waren diese Hinbildungen bis herab zu einer Reaktionstemperatur von 135° C zu verfolgen. So kann man feststellen, daß sich SiO₂-Substanzen semisalinar, bei milden Umwandlungsbedingungen zum Talk hin umsetzen lassen.     

Karsts polyphasés, faciès marins et continentaux dans le Paléocène de la partie orientale des Pyrénées fran?aises

In the Eastern part of French Pyrenees, the Cucugnan area (Southern Corbières) corresponded during the early/Mid-Paleocene (Danian/Selandian) to a narrow transitional zone between the sea to the South (Pyrenean Paleocene Trough) and the continent (fluvio-palustrine and lacustrine Vitrollian deposits) to the North. To the South, in the North-Pyrenean Zone, the polygenic marine breccias and the associated Dano-Selandian Globigerinid-bearing hemipelagites have been preserved within successive paleokarsts superimposed onto the carbonate substratum (ante-Albian). Four paleosurfaces are recognized, principally filled by marine internal sediments with proximal and distal facies. To the North, in the Sub-Pyrenean Zone, a continental foreland basin is characterized by four formations of variegated Microcodium-bearing marls and channelized conglomerates, separated by erosional paleosurfaces underlining well-marked unconformities. An event correlation (chronodiagrams) between the marine realm to the South and the continental realm to the North is proposed, using the successive paleosurfaces and the lithological sequences (same number within the two realms). Our paleogeographic reconstruction shows, to the North, the Lake of Cucugnan and, to the South, a calcareous mountainous zone broken by the juxtaposition of deep paleocanyons (eroded in a continental context) later converted into rias submitted to marine oscillations. Several palinspastic transects are reconstructed: they show the polyphase control of the Frontal North-Pyrenean Overthrust on the Paleocene sedimentation and the importance of the successive intra-Vitrollian compressions/ transpressions (phase fini-crétacée auct.) inducing, within the two juxtaposed realms, emersions, erosions and karstic features which give a very contrasted paleogeography during a period characterized by plate convergence and creation of steep topographies.Manuscrit reçu le 25 septembre 2003 Révision acceptée le 4 mai 2004     

Neue Ergebnisse zur Gliederung der unterpermischen Eruptivfolge der Bozener Porphyr-Platte

Zusammenfassung Am Südrand der Bozener Porphyr-Platte (im Raum nordöstlich von Trento) konnte auf Grund neuer Untersuchungen für die unterpermische Eruptivfolge eine Zweiteilung gewonnen werden, die mit der bisher für diesen Bereich geltenden Gliederung (Trener 1904, 1933) in Widerspruch steht. Die untere, basische, Basale Tuff-Serie genannte Abteilung wird neben einzelnen eingeschalteten Melaphyr- und Porphyritlagen hauptsächlich von Kristall-, Aschen- und Agglomerattuffen zusammengesetzt. Den hangenden, saueren Komplex nehmen Quarzporphyre und untergeordnet Tuffe der Lagorai-Quarzporphyr-Serie ein.Am Nord-, West- und Ostrand der Bozener Porphyr-Platte ist im großen ganzen eine ähnliche Zweiteilung beobachtbar. Hier entspricht der Basalen Tuff-Serie des Trentiner Bereiches der Trostburg-Melaphyr-KomplexWolffs (1909). Dagegen sind der Porphyr von St. Ulrich, der Eggentaler, Branzoller, Hocheppaner und der Kasteiruther PorphyrWolffs (1909) nicht zeitlich nacheinander gebildete Lavaströme, sondern nur lokale Varietäten ein und derselben Ergußphase. Sie sind lithologisch und zeitlich dem Lagorai-Quarzporphyr des Südrandes gleichzusetzen.     

Phanerozoic history of Western Australia related to continental drift

From north to south, the sedimentary basins of Western Australia change from broad platforms of wholly marine strata that span the entire Phanerozoic (Bonaparte Gulf and Canning Basins) through the intermediate Carnarvon Basin to rifts of nonmarine Permian and Mesozoic strata (Perth Basin). These contrasts in age, facies, and structure reflect different positions of the basins in Gondwanaland: the Bonaparte Gulf and Canning Basins have lain at the continental margin facing an open ocean during the entire Phanerozoic, whereas the Perth Basin lay in the interior of Gondwanaland until India and Australia moved apart in the Cretaceous.

The Eucla Basin came about by events connected with the dispersal of Antarctica and Australia in the Eocene. The northwest part of the Australian Block (Timor and the Timor Sea) was deformed in the Miocene when Australia collided with southeast Asia.     

Integrated oil exploration decision systems

The fully integrated, analytical decision system can be developed for petroleum exploration. Such a system would use conditional probability estimates of wildcat drilling success, based on biologic variables. These probabilities can be combined with financial analyses to produce Assessments of optimum exploration strategies.This paper was presented at Symposium 116.3, Quantitative Strategy for Exploration, held as part of the 25th International Geological Congress, Sydney, Australia, August 1976.     

Über Beraunit-Eleonorit

Zusammenfassung Eleonorit von den Gruben Eleonore am Dünnberg bei Gießen und Rothläufehen bei Waldgirmes unweit Wetzlar zeigt außer den vonStreng ermittelten Formen noch das Pinakoid {102}. Die röntgenographische Untersuchung führte auf einec-flächenzentrierte monokline Elementarzelle von folgenden Ausmaßen.a ₀ = 20,59 Å,b ₀ = 5,152 Å,c ₀, = 19,23 Å, = 94° 06;a ₀ :b ₀ :c ₀ = 3,997: 1 : 3,7325. Ihre Elemente stehen zu denStrengschen Kristallelementen in folgender Beziehung:Streng zu neu vermöge , neu zuStreng vermöge . Die Raumgruppe, ist C2/c.Die pyknometrische Dichte beträgt 3,01; die chemische Formel ist Fe ₆ ^III (OH)₆ (PO₄)₄ · 5H₂O; die Elementarzelle enthält 4,066 4 Formeleinheiten.Eleonorit von den Gruben Eleonore und Rothläufehen ist identisch mit Beraunit von Auerbach/Opf., von Kreuzberg-Pleystein und von Zbirow (SIR), zu Viviant und Dufrenit bestehen keine Beziehungen. Ob der Beraunit vom, ursprünglichen Fundort St. Benigna bei Beraun mit Eleonorit identisch ist, ließ sich nicht ermitteln.     

Bemerkungen zu A.Tollmann's tektonischer Synthese der Ostalpen

Zusammenfassung Nach gekürzter Wiedergabe eines Teiles der von A.Tollmann gestellten Problematik werden Einzelheiten kritisch besprochen (Überschiebung der Gurktaler Decke und Fenster, Rannachserie, Alter der Metamorphose, des Mesozoikums? und des Hochkristallins, Gumpeneckmarmor, aufgeschlossene Überschiebungsweiten).In der anschließenden Darstellung wird auf die Bedeutung des Lavanttaler Störungssystems hingewiesen. Die Vielphasigkeit der Bewegungen und der Wechsel der Richtungen zur Zeit der alpinen Baupläne lassen die Lavanttaler Störung als eine alpin umgestaltete Geofraktur (von Gaertner) erscheinen. An ihr wurde der alpine Bauplan zerschnitten, und die ostalpinen Deckenelemente wurden vor allem im Raume der Niederen Tauern — Grauwackenzone in eine sich gegen Westen und Osten steigernde Einwalzung der Schuppen einbezogen, denen die kristalline Basis gemeinsam ist.     

Some major concepts of metallogeny

These notes, which summarize part of over ten years of laboratory work, aim to clarify and inter-relate three fundamental concepts of current Metallogeny: consanguinity, heritage, province. — 1. The concept of consanguinity: its criteria, limits and graduations, are first presented; 2. They are illustrated by the analysis of a complex example: the lead-zinc mineralisations in Trias around the Cévennes (South of the French Massif Central); 3. The likelihood of consanguinity for various strata-bound mineralisations, particularly misappreciated and misinterpreted, is then shown: — tungsten in the Cévennes — gold at Passagem (Brazil), about which microstructural and geochemical arguments are especially employed — cobalt at Bou Azzer (Marocco); 4. From consanguinity in a sedimentary environment, the authors turn to the crustal phenomena cycle, during which the heritages of the cations succeed one another. Examples of heritages, linked with sedimentation-volcanism: Sierra de Carthagena (Spain) — metamorphism — granitisation, are rapidly examined or referred to in literature. Particular attention has been paid to heritage by secretion, illustrated by the antimony lodes of the French Massif Central. Consequently, it may be understood how the successive heritages involve geochemical permanences and determine the geochemical provinces going back to ancient times in which the mineral provinces were built up. 5. In a last section the transformist guide line is compared with other concepts and tools of Metallogeny: lineaments and isotopic ratios. — In conclusion, the intra-crustal heritages still remain under-estimated and badly deciphered and are not sufficiently taken into consideration in mineral exploration.

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Zusammenfassung Diese Veröffentlichung, die einen Teil der während eines Jahrzehnts in einem Laboratorium ausgeführten Arbeiten kurz behandelt, hat die Aufgabe, drei Grundbegriffe der gegenwärtigen Metallogenese klarzustellen und miteinander zu verknüpfen: Familiarität (Verwandtschaft), Vererbung und Provinz. — 1. Der Begriff der Verwandtschaft sowie seine Kriterien, Grenzen und Nuancen werden zuerst auseinandergesetzt. 2. Dann wird dieser Begriff anhand der Analyse eines komplizierten Beispiels veranschaulicht, und zwar der Blei-Zink-Mineralisationen in der Trias am Rand der Cevennen, im Süden des französischen Zentralmassivs gelegen; 3. Anschließend wird die Wahrscheinlichkeit der Verwandtschaft für verschiedene schichtgebundene, besonders verkannte und falsch interpretierte Mineralisationen aufgezeigt. Es handelt sich einerseits um das Wolfram der Cevennen sowie das Kobalt von Bou Azzer (Marokko) und andererseits um das Gold von Passagem (Brasilien), zu dessen Erklärung insbesonders mikrostrukturelle und geochemische Argumente herangezogen werden; 4. So gelangt man in den Kreislauf der Krustalerscheinungen, währenddessen Vererbungen von Kationen aufeinanderfolgen. Beispiele von Vererbungen, die an Sedimentation, Vulkanismus (Sierra von Cartagena, Spanien), Metamorphose und Granitisierung gebunden sind, werden kurz untersucht oder anhand von Literaturangaben erwähnt. Besondere Erwähnung verdient die Sekretionsvererbung, die am Beispiel der Antimonerzgänge des französischen Zentralmassivs veranschaulicht wird. Somit wird verständlich, wie die aufeinanderfolgenden Vererbungen geochemische Beständigkeiten bedingen. Sie bestimmen ebenfalls geochemische, auf das hohe Altertum zurückgehende Provinzen, auf denen sich die Mineralprovinzen aufbauen; 5. Zum Schluss wird diese transformistische Leitrichtung mit anderen Konzepten und Arbeitsmitteln der Metallogenese verglichen: den Lineamenten und Isotopenverhältnissen. — Es wird der Schluß gefolgert, daß die intrakrustalen Vererbungen immer noch unterschätzt, schlecht entziffert und bei der Lagerstättenforschung ungenügend in Betracht gezogen werden.

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Illustrated by Examples

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Laboratory associated with the C.N.R.S. (n^o 65). Contributors to this paper: P. Routhier (former Director of the Laboratory at present Director in the B.R.G.M.) and P. Brouder, R. Fleischer, (at present in the Penarroya C⁰), J. C. Macquar, Melle M. J. Pavillon, G. Roger and H. Rouvier.     

Rivers in Australia

As a continent, Australia is unusual. It has a long history of habitation by a relatively small population of Aboriginals with a low technology culture. Just over 200 years ago, in 1788, it was invaded by a technological society from the UK, and the settlers brought with them an understanding of rivers and the landscapes in which they were situated which was quite at odds with the reality of the Australian continent. Australia is a piece of old continental crust derived from the break-up of Gondwana that, unlike other Gondwana continents, has experienced little tectonic modification since the break-up. It is a low relief continent dominated by arid and semi arid climates. Australian river systems have poor slope-channel coupling and poor hydrological connectivity and are characterized by low rates of sediment delivery. The flow of Australian rivers has high interannual variability, two to three times that of comparable rivers elsewhere, and highly variable flood behavior. In this paper, examples are given of particular Australian rivers to illustrate the manner in which the morphological and climatic characteristics of the continent combine to produce some distinctive river systems.     

Titania precipitation in sapphire containing iron and titanium

Titania, TiO₂, precipitation in natural blue sapphire (Fe, Ti: -Al₂O₃) has been investigated using high resolution and analytical transmission electron microscopy. The structure and habit of the TiO₂ precipitate depends on both the Ti⁴⁺ concentration and the temperature at which the precipitate formed. Tetragonal TiO₂ (Rutile) grows at 1350° C but at 1150° C an orthorhombic non-equilibrium TiO₂ polymorph precipitates. Both TiO₂ polymorphs nucleate in the (0001)s plane as lens shaped discs twinned along their diameter. The crystallographic alignment of each type of TiO₂ precipitate with respect to the -Al₂O₃ host matrix provides a high degree of structural coherency with minimal lattice mismatch. Electron diffraction analysis established the following precipitate/host orientation relationships: tetragonal TiO₂: {011}r {11 07B;100}r(0001)s and 01 r10 0s twinned along the (011)r planeand orthorhombic TiO₂: {021}{11 0}s, {100}(0001)s and 0 2 10 0s twinned along the (021) plane.