II. Geophysik Die geophysikalische Erforschung Nordwestdeutschlands im Zeitraum 1932–1947, ein Überblick

Ohne Zusammenfassung     

Spatial and temporal variation in the abundance and composition of ichthyoplankton in a large South Island,New Zealand river estuary

Larval and juvenile fish drifting on ebb tides were collected from early summer to mid autumn at various locations in the Taieri River and Waipori River estuary, South Island, New Zealand. A total of seven species of fish were recorded, however only three species were regularly collected. These were the larval common bully (Gobiomorphus cotidianus McDowall), larval inanga (Galaxias maculatus Jenyns), and postlarval cockabully (Tripterygion nigripenne Valenciennes). Common bully densities were highest in mid January, with the highest densities being recorded drifting out of Lake Waihola. Inanga densities were highest in March and April, with the highest densities being recorded in the channels draining wetland areas where extensive tidal inundation of riparian vegetation occurred. Cockabully were recorded from February to April, mostly at more downstream sites. Inland penetration by marine species was considerable, with two marine species, clingfish (Trachelochismus pinnulatus Forster) and smooth leatherjacket (Parika scaber Forster), being recorded c. 12 km upstream in late summer.     

Regional geochemical prospecting in Calabria, Southern Italy

A governmental regional drainage survey assessed the mineral potential of Calabria in 1974. The Calabria area of southern Italy is a mineralized region in which Penninic and Austro-Alpine nappes, comprising ophiolites, metasedimentary rocks (phyllites, paragneiss, granulites, amphibolites) and granitic and granodiorite plutons, are overthrusting carbonate Apenninic nappes. Pre-Alpine stratabound and vein-type base-metal sulfide mineralization predominate, tectonically redistributed during the Alpine orogeny.A total of 5518 samples of the original 6999 active stream sediments from an area of 10,000 km² were analyzed by X-ray fluorescence and atomic absorption for Cu, Pb, Zn, Hg, Fe, Mn, As, W, Mo, Sn, and Be on the minus 180 μm fraction. Follow-up investigation of a 39-km² area around Bivongi-Ferdinandea using 760 soil samples analyzed for Fe, Mn, Zn, Cu, Pb, K, Mo, and Au, investigated molybdenite and chalcopyrite occurrences associated with granodiorite.A five-factor R-mode factor analysis reflected geological and mineralization features in the reconnaissance data. Factor 1 (Fe-Mn-Cu-Zn) is related to the Fe and Mn distribution in the stream sediments. Factor 2 (Be-Sn) reflects presence of pegmatites within metamorphic and magmatic rocks. Factor 5 (Mo) is essentially a single-element factor. Factor 4 (As-Pb-Zn-Hg-Cu) reflects mineralization. Factor 3 (W-Ba) does not cluster in association with any specific lithological unit. Significant metal associations, recognized from R-mode factor analysis, were used as independent variables and regressed against the original metal concentration of each sample. Residuals of multiple regression analysis, differentiated features representing mineralization from those related either to lithologic or geochemical parameters. New prospecting targets were identified and areas of known mineral occurrences were evident in the distinction of residuals.R-mode factor analysis of data from the follow-up investigation identified three factors. Factor 2 (Mo-K) reflects Mo mineralization and associated hydrothermally altered areas but does not suggest additional target areas.     

Rotenone treatment has a short-term effect on New Zealand stream macroinvertebrate communities

Invasive fish eradication is a key management strategy in aquatic ecosystems, and is often accomplished using piscicides such as rotenone. However, the effects of piscicides on aquatic invertebrate communities are poorly understood, particularly over long time scales. We monitored invertebrate communities in two treatment and two reference streams prior to and for one year following the use of rotenone to eradicate trout in Zealandia wildlife sanctuary, Wellington. Immediately following treatment, invertebrate density and taxonomic richness declined significantly, and community composition diverged markedly relative to reference streams, with pollution sensitive taxa declining greater than more tolerant taxa. Treatment streams recovered to pre-treatment conditions within 4–12 months of rotenone application, indicating minor long-term impacts on invertebrate communities. Speed of recovery of individual taxa appeared to be associated with life history variables, e.g. generation times and dispersal ability. Untreated upstream reaches and nearby water bodies likely facilitated successful invertebrate community recovery. Our results demonstrate that rapid recovery of New Zealand stream invertebrate communities is possible within one year of rotenone application.     

Der tiefere Untergrund der Alpen nach neuen seismischen Messungen

Zusammenfassung Anhand einer zu diesem Zweck zusammengestellten Schwerekarte werden die Ergebnisse sowohl von Sprengserien in West- und Ostalpen als auch von Beobachtungen in den Vorländern diskutiert. Eine Alpenwurzel, die von der Mohorovii-Diskontinuität abgebildet wird, kann als nachgewiesen gelten. Starke Verdickungen der Gabbro-Schicht in den Alpen und im Bereich positiver Schwereanomalien am Innenrand der Alpen sind äußerst wahrscheinlich. Die Störkörper am südlichen Innenrand der Alpen haben, wie aus dem seismisch untersuchten Teil der Anomalie von Ivrea gefolgert wird, ähnliche Größenordnung wie der Gabbrokörper unter den Alpen. Auf formale Beziehungen zu Verhältnissen im Karibischen Meer wird hingewiesen.

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The results of a series of explosions in the West- and East Alps as well as of observations made in the forelands of the Alps are here discussed with the aid of a gravity map especially compiled for this purpose. A root of the Alps clearly shown by the Mohorovii discontinuity can be considered as ascertained. Strong thickenings of the basaltic layer in the Alps and within the reach of positive gravity anomalies are extremely probable. From the seismically examined part of the Ivrea anomaly is concluded that the disturbing bodies at the southern inner border of the Alps are of the similar order of magnitude as the basaltic body below the Alps. Formal relations to conditions in the Caribbean Sea are pointed out.

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Résumé A l'aide d'une carte de gravité, compilée spécialement à cette fin, on discute les résultats obtenus par des séries d'explosions dans les Alpes occidentales et orientales comme aussi par des observations faites dans les avant-pays. Une racine des Alpes tracée par la discontinuité de Mohorovii peut être considérée comme prouvée. Il est très probable qu'il existe de forts renflements de la couche de gabbro dans les Alpes et dans le domaine d'anomalies positives de gravité au bord intérieur des Alpes. Les massifs failleux au bord intérieur méridional des Alpes se placent — ce qui s'ensuit de la partie examinée par les experiences séismologiquès de l'anomalie d'Ivrea — dans le même ordre de grandeur comme le massif de gabbro au dessous des Alpes. On indique des relations formales par rapport à des conditions existant dans la mer des caraïbes.

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Vortrag gehalten auf der Jahrestagung der Geologischen Vereinigung in Bern, März 1963.     

Abundance of brown trout as related to littoral zone gradient in Lakes Te Anau and Manapouri,New Zealand

Adult brown trout (Salmo trutta L.) in lakes are primarily littoral/benthic foragers. We predicted that the distribution of adult brown trout in lakes would be shaped by foraging demands, and that they would be more abundant in gently sloping littoral areas, that is, littoral areas that have a greater space available to support benthic foraging habitats. To address this hypothesis, we measured abundance of brown trout among littoral areas with different gradients in Lakes Te Anau and Manapouri. There was a significant negative relationship between littoral zone gradient and relative abundance (CPUE) of adult brown trout. This result supports the hypothesis that brown trout aggregate in littoral areas with greater amounts of foraging habitat in Fiordland lakes.     

First capture and description of larval torrentfish (Cheimarrichthys fosteri) during their seaward migration

While many of New Zealand’s freshwater fishes undertake larval migrations as part of their amphidromous life-history, little is known of the larval stages of these fish. Torrentfish (Cheimarrchthys fosteri), a New Zealand endemic, amphidromous, riffle specialist are particularly enigmatic; their spawning sites and behaviours are unknown, and larvae have never been collected either emigrating from freshwater or during their marine feeding phase. During summer drift sampling, we captured unidentified fish larvae emigrating downstream in the Waianakarua River, South Island, New Zealand. Based on multiple lines of evidence (meristic comparisons with adults, morphology, time of capture, and adult fish populations of the Waianakarua) we identify these larvae as torrentfish. This represents the first time torrentfish larvae have been captured or identified, laying the foundations for future studies into the early life-history and ecology of this unique and threatened fish.     

Ulrich Schwarz-Schampera,Peter M. Herzig: Indium: geology,mineralogy, and economics

Mineralium Deposita -