On the Characteristics of Heavy Multiple-Day Snowfalls in the Eastern Alps

Based on the daily fresh-snowrecordings of a set of 81 stations of the AustrianHydrographic Service, covering a 19-year period,various aspects of extraordinarily long-lasting severesnowfalls are investigated. Starting from an exactdefinition of periods of Heavy Snowfall Events (HSE),some of the discussed items include the annual andseasonal frequencies of intense snowfall episodes, thelocation and migration paths of the storm centers andthe volume of snow dropped by the individual storms.Another part of the study, designed to visualize thebig variability of snow-related parameters over Alpineterrain, determines for all involved sites maximalobserved and theoretical extreme fresh-snowaccumulations for periods of variable length. Heavythree-day snowfall events are analyzed with specialregard of the resulting avalanche threat.     

Contemporary and palaeo channel patterns and the late quaternary stratigraphy of Cooper Creek,Southwest Queensland,Australia

Braided and anastomosing channels make up two major coexistent networks in the mud-dominated fluvial system of Cooper Creek, Southwest Queensland. The floodplain is characterized by a system of mud braids operative when floods inundate the whole alluvial surface. Anastomosing channels are inset deeper into the floodplain, operate at modern flows, and transport a traction load of sand. Shallow stratigraphic data show that an underlying sand sheet is unrelated to surface channel patterns and was formed by a system of meandering streams. According to preliminary dates based on thermoluminescence, the change from a sand- to mud-dominated fluvial regime took place between 50 000 and 200 000 years B.P., and probably reflects increasing aridity.     

Clod Size and Moisture Condition Influence on the Shearing Behavior of Compacted Soil

This paper presents results of the influence of clod size and initial moisture condition on the shearing behavior of a clayey soil with a plasticity index of 22. The clods were divided into different size categories, and then two groups of samples were prepared; samples with large clods (LC = clod size less than 38 mm) and samples with small clods (SC = clod size less than 4.75 mm). Two initial moisture conditions were achieved using two different moisture tempering times of 0 and 14 days. All samples were compacted to the same density and moisture content (95 % of maximum dry density and 2 % dry of optimum moisture content). Triaxial compression tests, including constant water content unsaturated tests and backpressure saturated, isotropically consolidated, undrained compression tests were performed at different confining pressures. At 0-day tempering time, samples prepared using large clods were found to be stiffer and stronger than those prepared using small clods. However, at 14-day tempering time, the strength of both LC and SC samples was similar.     

Discriminant Analysis for Compositional Data Incorporating Cell-Wise Uncertainties

Mathematical Geosciences - In the geosciences it is still uncommon to include measurement uncertainties into statistical methods such as discriminant analysis, but, especially for trace elements,...     

Geostatistics for Compositional Data: An Overview

Mathematical Geosciences - This paper presents an overview of results for the geostatistical analysis of collocated multivariate data sets, whose variables form a composition, where the components...     

Cu- and Mn-bearing tourmalines from Brazil and Mozambique: crystal structures, chemistry and correlations

Cu- and Mn-bearing tourmalines from Brazil and Mozambique were characterised chemically (EMPA and LA-ICP-MS) and by X-ray single-crystal structure refinement. All these samples are rich in Al, Li and F (fluor-elbaite) and contain significant amounts of CuO (up to ~1.8 wt%) and MnO (up to ~3.5 wt%). Structurally investigated samples show a pronounced positive correlation between the <Y-O> distances and the (Li + Mn²⁺ + Cu + Fe²⁺) content (apfu) at this site with R ² = 0.90. An excellent negative correlation exists between the <Y-O> distances and the Al₂O₃ content (R ² = 0.94). The samples at each locality generally show a strong negative correlation between the X-site vacancies and the (MnO + FeO) content. The Mn content in these tourmalines depends on the availability of Mn, on the formation temperature, as well as on stereochemical constraints. Because of a very weak correlation between MnO and CuO we believe that the Cu content in tourmaline is essentially dependent on the availability of Cu and on stereochemical constraints.     

Provenance of the Upper Cretaceous to Eocene Gosau Group around and beneath the Vienna Basin (Austria and Slovakia)

Chemistry of detrital garnets, chrome spinels and tourmalines of 30 selected samples in combination with the general heavy mineral distribution from 523 sandstone samples of the Upper Cretaceous to Eocene Gosau Group of the eastern part of the Eastern Alps and the western West Carpathians result in an advanced picture of sedimentary provenance and palaeogeographic evolution of that area. Garnets from Coniacian to Campanian sediments are partly derived from a metamorphic sole remnant of Neotethys ophiolites to the south. Tectonically high ophiolitic nappes, later on completely eroded, supplied mainly the paleogeographically southern Grünbach and Glinzendorf Gosau basins with ultramafic detritus, represented by chrome spinels of a mixed harzburgite/lherzolite composition, whereas no direct indications for a northern ophiolitic source, the Penninic accretionary wedge to the north of the Gosau basins, could be found. In the younger part of the Gosau basins fill, from the Maastrichtian to the Eocene, only almandine-rich garnets could be observed suggesting a southern provenance from low-grade metamorphic metapelites of exhuming Austroalpine metamorphic complexes. Ophiolite detritus is reduced in the Maastrichtian and disappears in the Paleogene.