Über den „jüngeren Geschiebemergel“ auf Jasmund

Zusammenfassung Die Auffassung, ein jüngerer, die Stauchfalten auf Jasmund diskordant überlagernder Geschiebemergel bezeuge eine Eisbedeckung, wird angezweifelt. Es wird darauf hingewiesen, daß die Jasmunder Stauchfalten im Gegensatz zu den rezenten sandig-kiesigen Stauchmoränen Spitzbergens und Grönlands aus Grundmoräne und Kreide bestehen. Da die Köpfe dieser Stauchschuppen periglacialer Umlagerang ausgesetzt waren, muß in den Senken zwischen ihnen ein grundmoränenartiges, an Kreide reiches Gestein mit ebener Oberfläche erwartet werden. Der jüngere Geschiebemergel Jasmunds entspricht in Zusammensetzung, Verbreiterung und Mächtigkeit diesen Voraussetzungen und dürfte somit ein sekundärer Geschiebemergel sein.     

Geologischer Kompass

Zusammenfassung Der Verf. unternimmt den Versuch, einen auch für die geologische Vorzeit anwendbaren Indikator für die Nord-Südrichtung zu finden. Die Lösung dieses Problems würde gleichzeitig die Frage nach der Realität von Pol- und Kontinentalwanderungen beantworten. Der brauchbare Kompaß wird in der im Verlauf der Untersuchungen entdeckten «Nickels'schen Regel» gefunden. Diese besagt, daß die mit Hilfe einer genügenden Anzahl von Bäumen (der Verf. untersuchte 200) gebildeten mittleren Stammradien nach den verschiedenen Himmelsrichtungen nicht gleich sind. Die Pflanzen sind nämlich bestrebt, die größtmögliche Lichtmenge zu empfangen. Zu diesem Zweck neigen sie sich zur Sonne, also auf der Nordhalbkugel nach Süden. Dies kann nur dadurch geschehen, daß die Pflanzen auf der Schattenseite stärker assimilieren. So erkärt sich die gefundene Tatsache, derzufolge der polare Radius der Baumstämme im Mittel aller Fälle der größte und der äquatoriale der kleinste ist. Nunmehr ist es also durchaus möglich, bei der Auffindung einer genügenden Anzahlautochthoner Stammfossilien unter Anwendung des «Geologischen Kompasses» die Nord-Südrichtung der entsprechenden Periode relativ genau zu bestimmen.

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Summary The author attempts to find an indicator which is applicable to geological antiquity as well as to the North-South bearing. The solution to this problem would, at the same time, provide an answer to the question concerning the reality of the movements of Poles and Continents. The serviceable compass is found in the course of the investigation, in the established «Nickels Rule». This signifies that given a sufficient number of trees (the author examined 200) the formed inner radii of treetrunks towards the various compass directions are not equal. The reason for this is to be sought in the fact that plants endeavoured to obtain the greatest possible amount of light. To this end they lean towards the sun, in the Northern hemisphere therefore, towards the South. This can only happen through the fact that the plants grow stronger on the side which is in shadow. In this way, the established fact is explained, in consequence of which the northerly radius of tree trunks is, on average in all cases the largest and the southerly radius is the smallest. It is now quite possible there-fore, when a sufficient number of autochthonous trunk fossils are discovered to determine relatively exactly by using the «Geological Compass», the North-South bearing of the particular period.

     

Silicon control of strontium and cesium partitioning in hydroxide-weathered sediments

Cation partitioning and speciation in an aqueous soil suspension may depend on the coupling of reaction time, sorbate amount and mineral weathering reactions. These factors were varied in sediment suspension experiments to identify geochemical processes that affect migration of Sr²⁺ and Cs⁺ introduced to the subsurface by caustic high level radioactive waste (HLRW). Three glacio-fluvial and lacustrine sediments from the Hanford Site (WA, USA) were subjected to hyperalkaline (pH > 13), Na-Al-NO₃-OH solution conditions within a gradient field of (i) sorptive concentration (10⁻⁵-10⁻³ m) and (ii) reaction time (0-365 d). Strontium uptake (q_Sr) exceeded that of cesium at nearly all reaction times. Sorbent affinity for both Cs⁺ and Sr²⁺ increased with clay plus silt content at early times, but a prolonged slow uptake process was observed over the course of sediment weathering that erased the texture effect for Sr²⁺; all sediments showed similar mass normalized uptake after several months of reaction time. Strontium became progressively recalcitrant to desorption after 92 d, with accumulation and aging of neoformed aluminosilicates. Formation of Cs⁺ and Sr²⁺-containing cancrinite and sodalite was observed after 183 d by SEM and synchrotron μ-XRF and μ-XRD. EXAFS data for q_Sr ≈ 40 mmol kg⁻¹ showed incorporation of Sr²⁺ into both feldspathoid and SrCO₃(s) coordination environments after one year. Adsorption was predominant at early times and low sorbate amount, whereas precipitation, controlled largely by sediment Si release, became increasingly important at longer times and higher sorbate amount. Kinetics of contaminant desorption at pH 8 from one year-weathered sediments showed significant dependence on background cation (Ca²⁺ versus K⁺) composition. Results of this study indicate that co-precipitation and ion exchange in neoformed aluminosilicates may be an important mechanism controlling Sr²⁺ and Cs⁺ mobility in siliceous sediments impacted by hyperalkaline HLRW.     

Fault slip analysis in the Koralm Massif (Eastern Alps) and consequences for the final uplift of “cold spots” in Miocene times

The Paleogene and Neogene evolution of Austroalpine basement units east of the Tauern Window is characterised by the formation of two major sets of faults: (1) ESE–WNW- to E–W-trending faults, associated with ENE- and NNW-trending conjugate structures and (2) N–S to NNE-SSW striking structures, mainly acting as high-angle normal faults, often associated with E-dipping low-angle normal faults along the western margin of the Styrian Basin.Together with the stratigraphic evolution of the Styrian and Lavanttal Basins and the related subsidence histories a tectonic evolution may be reconstructed for this part of the Eastern Alps. In the southern part of the Koralm Massif, WNW-trending fractures were activated as dextral strike-slip faults, associated with the evolution of WNW-trending troughs filled up with coarse block debris. W- to WNW-trending fractures were reactivated as normal faults, indicating N–S extension. It is assumed that these phases resulted in subsidence and block debris sedimentation in Karpatian and Badenian times (ca. 17–13 Ma).In the Western Styrian Basin no Sarmatian (13–11.5 Ma) sediments are observed; Pannonian (11.5 to 7.1 Ma) sediments are restricted to the Eastern Styrian Basin. This indicates, that the Koralm basement and the Western Styrian Basin were affected by post-Sarmatian uplift, coinciding with a re-activation of N-trending normal faults along the eastern margin of the Koralm Massif. Therefore, we suggest that the final uplift of the Koralm Complex, partly together with the Western Styrian Basin, occurred during the early Pannonian (at approximately 10 Ma). The elevation of clastic deposits indicates that the Koralm Complex was elevated by approximately 800 m during this phase, associated with an additional phase of E–W-directed extension accommodated by N–S striking normal faults.     

Where have all the people gone? The limits of resilience in coastal communities

The concept of resilience has been used to assess community development and its prospects in natural resource-based localities. The objectives of the article are to evaluate the resilience of two Icelandic coastal communities, and to reflect on the possible shortcomings of the resilience concept for providing policy guidance. Mixed qualitative methods were used, with several weeks of fieldwork in each location. The results showed that the two case communities have had to adjust to a radical change in the fisheries management, with the loss of resource entitlements. Additionally, substantial differences were found in their level of resilience. One community was undergoing a transition towards a non-fisheries-based existence through several innovative new initiatives, while the other was struggling to adjust and seemed to have reached its limits of resilience, as witnessed by continuing outmigration and declining services. A state-sponsored programme to rekindle the local economy has had limited success so far. The authors conclude by identifying some of the limitations of the focus on endogenous strategies in much of the resilience literature, which does not pay much attention to the broader political economy.     

Automatic Update of Road Attributes by Mining GPS Tracks

Despite advances in cartography, mapping is still a costly process which involves a substantial amount of manual work. This article presents a method for automatically deriving road attributes by analyzing and mining movement trajectories (e.g. GPS tracks). We have investigated the automatic extraction of eight road attributes: directionality, speed limit, number of lanes, access, average speed, congestion, importance, and geometric offset; and we have developed a supervised classification method (decision tree) to infer them. The extraction of most of these attributes has not been investigated previously. We have implemented our method in a software prototype and we automatically update the OpenStreetMap (OSM) dataset of the Netherlands, increasing its level of completeness. The validation of the classification shows variable levels of accuracy, e.g. whether a road is a one‐ or a two‐way road is classified with an accuracy of 99%, and the accuracy for the speed limit is 69%. When taking into account speed limits that are one step away (e.g. 60 km/h instead of the classified 50 km/h) the classification increases to 95%, which might be acceptable in some use‐cases. We mitigate this with a hierarchical code list of attributes.