Buchbesprechungen

Ohne Zusammenfassung     

Hydrography of the Santee River during moderate discharge conditions

To harness hydroelectric power, most of the flow of the Santee River, SC was diverted in 1942 into Charleston Harbor, where shoaling promptly became a major problem. For this reason, most of the diverted flow is scheduled to be rediverted to the Santee within the next decade, increasing the mean discharge of the Santee from 74 to 428 m³s^?1. To assess the present hydrogrpahy of the Santee estuary under conditions of moderate discharge, we determined 226 vertical profiles of velocity, salinity, and temperature distributed over 17 stations in February, 1975. We found that 73 and 27% of the discharge reached the ocean via the North and South distributaries, respectively. The 1 ppt isohaline was found no further than 8 km upstream from the mouth, indicating the limited extent of the estuarine zone. The Santee is a partially mixed estuary classified as type 2b. The circulation parameter is approximately 3 and the stratification parameter approximately 0.3. The bulk parameters indicate the importance of tidal, mixing and a weakly developed gravitational circulation. When rediversion is completed, the net salinity in the lower Santee River can be expected to decrease drastically, which in turn is likely to terminate the lucrative oyster and clam fishery.     

A method to determine crystallization temperatures of hydrated crystals by intracrystalline oxygen isotope effects

The fractionation of the oxygen isotopes between water molecules from different sites in CuSO₄ · 5H₂O has been measured for crystallization temperatures of 25, 40 and 50°C. The temperature dependence found provides a basis for the determination of crystallization temperatures from such intracrystalline oxygen isotope effects; also for hydrated crystals of mineralogical and geological interest. Necessary suppositions for the application of this method are discussed.     

Determination of source and palaeoclimate from the comparison of grain and clay fractions in sandstones: A case study

The Paleogene Ke?an Formation of southwestern Turkish Thrace (Alpine Ergene basin) which is dominantly a sandy facies, comprises the Çinarlidere (Lower) and ?aplidere (Upper) members. The turbidite sandstones of the Formation are petrologically defined as multicycle, moderately sorted, angular to subrounded, coarse-skewed, submature graywackes with a detrital clayey matrix of over 15%.The quantitative analyses of light, heavy and clay fractions of sandstone samples from the Ke?an Formation showed marked petrographic variations with grouping of these sediments as Lower- and Upper-member mineralogical facies and led to the following conclusions: a southern terrain with a relatively warm and tropical climate on a terrestrial source of a peneplain topography provided detrital material for the Lower-member sediments (the Biga Massif), while the Upper-member sediments were derived from a rapid erosion of an area of high relief with a uniform supply and continuous infilling of the basin of deposition (a western source terrain: the Rhodope Massif).     

Ingenieurtechnische,geologische und mineralogische Probleme beim Bau einiger Tunnel der Tauernautobahn im Bereich von Werfen (Salzburg, Österreich)

Zusammenfassung Ingenieurtechnische, geologische und mineralogische Probleme beim Bau einiger Tunnel der Tauernautobahn im Bereich von Werfen (Salzburg, Österreich). In den Jahren 1974 bis 1976 wurden im Baulos 6 Werfen der Tauernautobahn (südlich von Salzburg) zwischen den Bau-Kilometern 34,2 und 42,3 insgesamt 3460 lfm Tunnel (Doppelröhren) ausgebrochen. Es sind dies, von N nach S gezählt, der Brentenbergtunnel, der Zetzenbergtunnel und der Helbersbergtunnel. Die Tunnelarbeiten wurden nach der Neuen Österreichischen Tunnelbauweise, überwiegend in konventionellem Sprengbetrieb (streckenweise auch mit Teilschnittfräse) durchgeführt.Im Brentenbergtunnel wurde nach Durchörterung einer im Norden vorgelagerten 60 m langen Hangschuttstrecke Ramsaudolomit durchfahren. Der Zetzenbergtunnel liegt in gut geschichteten Kalken und Dolomiten des Gutensteiner Niveaus. Im Helbersbergtunnel schließlich wurden beim Vortrieb von N nach den ersten 80 m, in denen noch Gutensteiner Kalke und Dolomite anstanden, Gips führende Quarzite, Quarzitschiefer und Sandsteine der Werfener Schichten durchörtert. Die Baugrubensicherung des Voreinschnittes am Nordportal des Brentenbergtunnels sowie Details zur bergmännischen Durchörterung der Hangschuttstrecke im Schutze eines Injektionsschirmes werden ausführlich beschrieben und weiters Sondermaßnahmen in den Gips führenden Strecken des Helbersbergtunnels sowie einige spezielle Beobachtungen zur Nachbrüchigkeit in diesem schwierigen Tunnelabschnitt behandelt.

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Summary Engineering, Geological and Mineralogical Problems With the Construction of Several Tunnels in the Course of the Tauern Highway (Salzburg, Austria). From 1974 to 1976 the Tauern Highway was further extended near Werfen in the federal state of Salzburg (Austria). Therefore a total tunnel length (twin tube tunnels) of 3460 meters was performed in the section from km 34,2 to 42,3. The three twin tube tunnels have been cut mainly through Lower and Middle Triassic members of the Northern Limestone Alps.Thus, the Brentenberg tunnel, 600 meters (eastern tube) and 540 meters (western tube) respectively, is situated in the so called Ramsau dolomite. The Zetzenberg tunnel, 503 m (eastern tube) and 500 m (western tube) respectively long, penetrates Gutenstein limestone and dolomite, whereas the main part of the longest tunnel, the Helbersberg tunnel, 750 m and 740 m respectively, traverses Werfen beds except its northernmost ninety meters in Gutenstein limestones and limey shales.Furthermore, tunneling through sixty meters of loose rock debris in the northern part of Brentenberg caused a lot of trouble. The holing of non-cohesive rock debris by means of the New Austrian Tunneling Method will be dealt with in detail as well as the supporting works for the surface entrances. Excavation site for Brentenberg tunnel portals was supported by a retaining wall of bored piles sunk at 30 to 90 centimeters centre. The bored piles were stabilized by means of anchors of up to 38 meters length. Tunneling through the section of loose rock debris was performed with the aid of injections of cement and bentonite grout at the crown and the side walls. By that means, the over-all property of the initially freely running loose debris could be improved up to rock quality class IV (classification according to Pacher and Rabcewicz).In the Helbersberg tunnel at least, as prognosticated by preliminary geological studies, two sections of gypsiferous rock, about 150 and 200 m respectively long, were encountered. Before taking precautionary measures, rock samples were collected at intervalls of several meters and investigated mainly by X-ray diffractometer therefore. The results showed, that gypsification of most of anhydrite has taken place in the rocks of Helbersberg already. Due to that fact, Thiodur — a sulphate-proof special cement — was used to construct the external supporting elements. Then, the supporting elements of the reinforced inner ring were performed in concrete quality B 400. Moreover, the inner ring had to be isolated completely by means of soft PVC-framework.Owing to a smoothly running teamwork of civil engineers and geologists optimal solution could be achieved for every problem on site.

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Résumé Problèmes techniques, géologiques et minéralogiques résultant de la construction de l'autoroute du Tauern dans la région de Werfen (Salzbourg, Autriche). Dans la section 6 Werfen de l'autoroute du Tauern, au sud de Salzbourg, on a construit pendant les années 1974–1976, entre les kms 34,2 et 42,3, des tunnels à deux tubes dont la longueur s'élève à 3460 mètres en total. Ce sont, énumérés selon la direction nord-sud: le tunnel Brentenberg, le tunnel Zetzenberg et le tunnel Helbersberg. Les travaux ont été effectués selon la Nouvelle Méthode Autrichienne de Construction de Tunnels, en grande partie par attaque conventionnelle à l'explosif, partiellement à l'aide de fraiseuse.Après le percement d'une section à éboulis instable d'une longueur de 60 mètres, on a traversé dans le tunnel Brentenberg de la dolomie Ramsau. Le tunnel Zetzenberg est situé dans des strates stables de calcaire et de dolomie du niveau de Gutenstein. Dans le tunnel Helbersberg, il a fallu percer d'abord, sur une distance de 80 mètres, du calcaire de Gutenstein et des dolomies, ensuite du quartzite gypseux ou schisteux et du grès des couches de Werfen.Le travail présenté décrit les consolidations de la fouille pour l'excavation à ciel ouvert débouché nord du tunnel Brentenberg et des détails concernant le percement minier de l'éboulis après installation, en tant que dispositif de sécurité, d'un écran d'injection. Il y est question aussi de mesures additionnelles prises le long des sections gypsifères du tunnel Helbersberg ainsi que d'observations particulières concernant l'écroulement dans ce passage difficile.

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