Zur Biologie vonSphaerotilus natans Kützing

Zusammenfassung Unter Zuhilfenahme eines festen N?hrbodens gelang die Reinkultur vonCladothrix dichotoma. Eine überführung vonCladothrix in die alsSphaerotilus natans bekannte Form gelang bei Kultivierung in einem flüssigen N?hrsubstrat nach Zusatz von Asparagin und bei h?ufiger Erneuerung des N?hrsubstrates. Dabei war es gleichgültig, ob als Ausgangsmaterial die natürliche Standortsform vonCladothrix oder die vonSphaerotilus gew?hlt wurde. Auf festen N?hrb?den stellte sich stets typischesCladothrixwachstum ein. Ebenso l?sst sich eine auf obige Weise erhalteneSphaerotilusausbildung bei Drosselung des N?hrstoffangebotes in eineCladothrixausbildung zurückführen. Die Frage nach der Verwandtschaft vonCladothrix undSphaerotilus kann danach dahingehend beantwortet werden, dassSphaerotilus natans als ?üppigkeitsform? vonCladothrix dichotoma aufzufassen sein dürfte. Beobachtungen anderer Autoren (zum BeispielKolkwitz, 1926, undPringsheim, 1951, 1952), würden damit eine Best?tigung erfahren. Durch die Annahme, dassSphaerotilus natans eine physiologisch bedingte Form vonCladothrix dichotoma darstellt, w?re zugleich eine Erkl?rung für die schlagartige Ausbreitung desSphaerotilus natans in Vorflutern mit Zuckerfabrikabw?ssern gegeben. Eine Zusammenstellung aller uns erreichbaren Literatur überSphaerotilus undCladothrix wird angefügt.     

An overview of the city of Gweru,Zimbabwe’s water supply chain capacity: towards a demand-oriented approach in domestic water service delivery

Following complaints about water shortages in some areas of Gweru, the paper assessed the availability of enabling capacities to efficiently and sufficiently deliver water to the residents of Gweru in line with the existing level of demand. The key inspected capacity aspects were infrastructure, human resources, finances and physical availability of raw water at source. Purposively selected informants from Zimbabwe National Water Authority (ZINWA) and Gweru city council (GCC) provided data on the infrastructural, financial and human resources situation of GCC. Dam levels data for Gweru’s three supply dams were obtained from ZINWA records through the assistance of Sanyati Catchment Hydrologist. The raw water availability was assessed with the aid of Mann–Kendall test using a 10 years period data set from 2003 to 2012 for trend analysis. Findings revealed that the water sources were not experiencing major changes in water levels, to be precise, the changes were insignificant. However, given the increase in population and demand, any slightest negative change in the supply chain would further widen the gap between supply and demand. The study also uncovered that GCC had challenges in terms of the infrastructure, mainly due to financial constraints. Notably, GCC was not experiencing high staff turnover, but it was however, seriously under staffed and failing to effectively monitor water use in the city. Therefore, strong financial injection is required to support staff and resuscitate the reticulation system. Given the perpetual water shortages in Gweru and the status quo in the supply chain, water demand management strategies, wastewater use and consumer education are consequently proposed as measures that would ensure continuous water supply for all needs in the city.     

A new classification of the Turkish terranes and sutures and its implication for the paleotectonic history of the region

The Turkish part of the Tethyan realm is represented by a series of terranes juxtaposed through Alpine convergent movements and separated by complex suture zones. Different terranes can be defined and characterized by their dominant geological background. The Pontides domain represents a segment of the former active margin of Eurasia, where back-arc basins opened in the Triassic and separated the Sakarya terrane from neighbouring regions. Sakarya was re-accreted to Laurasia through the Balkanic mid-Cretaceous orogenic event that also affected the Rhodope and Strandja zones. The whole region from the Balkans to the Caucasus was then affected by a reversal of subduction and creation of a Late Cretaceous arc before collision with the Anatolian domain in the Eocene. If the Anatolian terrane underwent an evolution similar to Sakarya during the Late Paleozoic and Early Triassic times, both terranes had a diverging history during and after the Eo-Cimmerian collision. North of Sakarya, the Küre back-arc was closed during the Jurassic, whereas north of the Anatolian domain, the back-arc type oceans did not close before the Late Cretaceous. During the Cretaceous, both domains were affected by ophiolite obduction, but in very different ways: north directed diachronous Middle to Late Cretaceous mélange obduction on the Jurassic Sakarya passive margin; Senonian synchronous southward obduction on the Triassic passive margin of Anatolia. From this, it appears that the Izmir-Ankara suture, currently separating both terranes, is composite, and that the passive margin of Sakarya is not the conjugate margin of Anatolia. To the south, the Cimmerian Taurus domain together with the Beydağları domain (part of the larger Greater Apulian terrane), were detached from north Gondwana in the Permian during the opening of the Neotethys (East-Mediterranean basin). The drifting Cimmerian blocks entered into a soft collision with the Anatolian and related terranes in the Eo-Cimmerian orogenic phase (Late Triassic), thus suturing the Paleotethys. At that time, the Taurus plate developed foreland-type basins, filled with flysch-molasse deposits that locally overstepped the lower plate Taurus terrane and were deposited in the opening Neotethys to the south. These olistostromal deposits are characterized by pelagic Carboniferous and Permian material from the Paleotethys suture zone found in the Mersin mélange. The latter, as well as the Antalya and Mamonia domains are represented by a series of exotic units now found south of the main Taurus range. Part of the Mersin exotic material was clearly derived from the former north Anatolian passive margin (Huğlu-type series) and re-displaced during the Paleogene. This led us to propose a plate tectonic model where the Anatolian ophiolitic front is linked up with the Samail/Baër-Bassit obduction front found along the Arabian margin. The obduction front was indented by the Anatolian promontory whose eastern end was partially subducted. Continued slab roll-back of the Neotethys allowed Anatolian exotics to continue their course southwestward until their emplacement along the Taurus southern margin (Mersin) and up to the Beydağları promontory (Antaya-Mamonia) in the latest Cretaceous–Paleocene. The supra-subduction ocean opening at the back of the obduction front (Troodos-type Ocean) was finally closed by Eocene north–south shortening between Africa and Eurasia. This brought close to each other Cretaceous ophiolites derived from the north of Anatolia and those obducted on the Arabian promontory. The latter were sealed by a Maastrichtian platform, and locally never affected by Alpine tectonism, whereas those located on the eastern Anatolian plate are strongly deformed and metamorphosed, and affected by Eocene arc magmatism. These observations help to reconstruct the larger frame of the central Tethyan realm geodynamic evolution.     

Dimerelloid rhynchonellide brachiopods in the Lower Jurassic of the Engadine (Canton Graubünden, National Park, Switzerland)

New brachiopods (Dimerelloidea, Rhynchonellida) from Lower Jurassic (?lower Hettangian) hemipelagic sediments of the Swiss National Park in south-eastern Engadine are described: Sulcirostra doesseggeri sp. nov. and Carapezzia engadinensis sp. nov. Sulcirostra doesseggeri is externally similar to S. fuggeri (Frauscher 1883), a dubious species, that could not be included in a comparative study, because relevant samples no longer exist. A single specimen was tentatively assigned to Sulcirostra ?zitteli (Böse 1894) by comparison of its external morphology with S. zitteli from the type locality. The partly silicified brachiopods are associated with sponge spicules, radiolarians and crinoid ossicles. Macrofossils are rare: dictyid sponges, gastropods, bivalves, crustaceans, shark teeth and scales of an actinopterygian fish. The Lower Jurassic sediments (Alpisella beds, a basal member of the Allgäu Formation) preserving the brachiopods belong to the Ortler nappe (Upper Austroalpine nappes). The exact age of the Alpisella beds is not known, as index fossils are lacking. Their stratigraphic position above the Rhaetian Kössen Formation and below the ammonite-dated Trupchun beds suggests a very Early Jurassic, probably early Hettangian age for the new brachiopod fauna. The new species of Sulcirostra and Carapezzia are confined to a very small geographic area, a peculiarity also observed in other Early Jurassic dimerelloid brachiopods. These brachiopods presumably adapted to current-dominated submarine highs, where their shells could not accumulate, except when trapped in submarine cavities or re-deposited in submarine fans. Transport by turbidity currents is suggested for the Early Jurassic dimerelloids from the Engadine. Problems with the generic definition of Sulcirostra and the higher rank classification of Carapezzia are discussed.     

An assessment of gully erosion along major armoured roads in south-eastern region of South Africa: a remote sensing and GIS approach

An assessment of gully erosion along road drainage-release sites is critical for understanding the contribution of roads to soil loss and for informed land management practices. Considering that road-related gully erosion has traditionally been measured using field methods that are expensive, tedious and limited spatially as well as temporally, it is important to identify affordable, timely and robust methods that can be used to effectively map and estimate the volume of gullies along the road networks. In this study, gullies along major roads were identified from remotely sensed data sets and their volumes were estimated in a Geographic Information Systems environment. Also, the biophysical and climatic factors such as vegetation cover, the road contributing surface area, the gradient of the discharge hillslope and rainfall were derived from remotely sensed data sets using Geographic Information Systems techniques to find out whether they could explain the morphology of gullies that existed in this area. The results of this study indicate that hillslope gradient (R²?=?0.69, α = 0.00) and road contributing surface area (R²?=?0.63, α = 0.00) have a strong influence on the volume of gullies along the major roads in the south-eastern region of South Africa, as might have been expected. However, other factors such as vegetation cover (R² = 0.52, α = 0.00) and rainfall (R² = 0.41 and α = 0.58) have a moderately weaker influence on the overall volume of gullies. Overall, the findings of this study highlight the importance of using remote sensing and Geographic Information Systems technologies in investigating gully erosion occurrence along major roads where detailed field work remains a challenge.     

A 40 ka record of temperature and permafrost conditions in northwestern Europe from noble gases in the Ledo‐Paniselian Aquifer (Belgium)

The Ledo‐Paniselian Aquifer in Belgium offers unique opportunities to study periglacial groundwater recharge during the Last Glacial Maximum (LGM), as it was located close to the southern boundary of the ice sheets at that time. Groundwater residence times determined by ¹⁴C and ⁴He reveal a sequence of Holocene and Pleistocene groundwaters and a gap between about 14 and 21 ka, indicating permafrost conditions which inhibited groundwater recharge. In this paper, a dataset of noble gas measurements is used to study the climatic evolution of the region. The derived recharge temperatures indicate that soil temperatures in the periods just before and after the recharge gap were only slightly above freezing, supporting the hypothesis that permafrost caused the recharge gap. The inferred glacial cooling of 9.5°C is the largest found so far by the noble gas method. Yet, compared to other palaeoclimate reconstructions for the region, recharge temperatures deduced from noble gases for the cold periods tend to be rather high. Most likely, this is due to soil temperatures being several degrees higher than air temperatures during periods with extended snow cover. Thus the noble‐gas‐derived glacial cooling of 9.5°C is only a lower limit of the maximum cooling during the LGM. Some samples younger than the recharge gap are affected by degassing, possibly related to gas production during recharge in part of the recharge area, especially during times of melting permafrost. The findings of this study, such as the occurrence of a recharge gap and degassing related to permafrost and its melting, are significant for groundwater dynamics and geochemistry in periglacial areas. Copyright © 2010 John Wiley & Sons, Ltd.     

Heat release from rooftops during rainstorms in the Minneapolis/St. Paul Metropolitan Area,USA

In the modeling of urban storm water runoff temperatures, the contribution of rooftops to the heating of rainfall runoff is usually neglected or not mentioned in the literature. In this paper we examine the accuracy of this assumption (a) by analyzing temperature data that we recorded on a residential rooftop, a commercial rooftop, and a concrete driveway, and (b) by simulating temperature profiles within rooftops and pavements, and estimating heat transfer amounts from these surfaces to rainfall runoff (‘heat export’). Analysis of both wet‐ and dry‐weather temperature data recorded in the Minneapolis/St. Paul metropolitan area (north‐central USA) over periods of several months leads to the conclusion that (a) a concrete driveway has a far greater capacity for heat storage and release than a shingled residential rooftop, and (b) an insulated commercial rooftop is able to store and release more heat than the residential rooftop. Unexpectedly, the rainfall events with the highest dew point (rainfall) and surface temperatures often occurred during late night or early morning hours, and not during daylight hours. The analysis of three rainfall events showed that the heat export from the commercial rooftop was roughly three times that of the residential rooftop, but only 30%–90% of the heat export from a concrete driveway. Maximum (potential) heat export was significantly higher for the driveway than for either rooftop. In conclusion, the results of the data analysis and heat export simulations support the assumption that residential rooftops contribute very little heating to runoff from rainfall, while commercial rooftops may have a thermal impact on rainfall runoff because of their greater thermal storage capacity. Commercial rooftops, in addition to asphalt and concrete pavements, should be considered when estimating water temperature of rainfall runoff from urbanized areas and the associated impact on the thermal regime of streams and fish habitat. Copyright © 2011 John Wiley & Sons, Ltd.     

Late Cretaceous extension overprinting a steep belt in the Northern Calcareous Alps (Schesaplana, R?tikon, Switzerland and Austria)

The Triassic to Cretaceous sediment succession of the Lechtal Nappe in the western part of the Northern Calcareous Alps (NCA) has been deformed into large-scale folds and crosscut by thrust and extensional faults during Late Cretaceous (Eoalpine) and Tertiary orogenic processes. The following sequence of deformation is developed from overprinting relations in the field: (D1) NW-vergent folds related to thrusting; (D2) N–S shortening leading to east–west-trending folds and to the formation of a steep belt (Arlberg Steep Zone) along the southern border of the NCA; (D3) E–W to NE–SW extension and vertical shortening, leading to low-angle normal faulting and recumbent “collapse folds” like the Wildberg Syncline. D1 and D2 are Cretaceous in age and predate the Eocene emplacement of the Austroalpine on the Penninic Nappes along the Austroalpine basal thrust; the same is probably true for D3. Finally, the basal thrust was deformed by folds related to out-of-sequence thrusting. These results suggest that the NCA were at least partly in a state of extension during the sedimentation of the Gosau Group in the Late Cretaceous.     

Peter G. Verity (1953–2009)

Dedication

Peter G. Verity (1953–2009)