Soil gases associated with rift zones in the Eastern Snake River Plain,Idaho, U.S.A.

Soil gases have been measured, utilizing petroleum nearsurface exploration techniques, in the volcanic province of the Eastern Snake River Plain, In Idaho, U.S.A. The analyses of the soil atmosphere included light hydrocarbon gases, helium, hydrogen, and carbon dioxide. Samples were collected in and near recent basaltic rift zones. Characterization of rift zone soil gases has indicated variability of their compositional and magnitude makeup. Suggestion of some deeper sourced gases having migrated through fractures in the rift zones is advanced. Also differences among the samples rift zones are presented.     

(Re) deposition of loess in southern Limbourg,the Netherlands 3. Field evidence for conditions of deposition of the middle and upper silt loam complexes,and landscape evolution at Nagelbeek

This paper is about conditions and processes during the accumulation of the Upper Pleniglacial Middle and Upper Silt Loam complexes at Nagelbeek, Limbourg, a Weichselian stratigraphical type locality. The complexes correlate with Hesbayan and Brabantian loesses in Belgium, formed between 28,000 and 12,400 yrs BP. They are characterized by sediment features (cracks, mass deformations, and cut-and-fill features) that are ascribed to a cryogenic regimen. The main Middle Silt Loam subunit contains contraction cracks deformed and further modified by masswasting. Intra-Upper-Pleniglacial pedogenic intervals are inferred from three greyish bands, from a truncated weathered zone surmounting the Middle Silt Loam, and from an aeolian-cumulic palaeosol at the base of the Upper Silt Loam. Latter two zones and an intervening erosional unconformity were cryogenically reworked, less than 22,000 yrs BP, to form a complex stratigraphical marker-zone: the ‘Horizon à Langues de Nagelbeek’. Morphological variants of the marker-zone are described. The geomorphic evolution of the Nagelbeek upland, from Saalian to Holocene times, is summarized in unconformity maps and a time diagram.     

Normalized 87Sr86Sr by multiple collection and comparison to a standard

A system for precisely determining normalized ${}^{87}\text{Sr}{}^{86}\text{Sr}$ by comparing unknown to standard in a solid-source quadruple-collector mass spectrometer is outlined. This is made possible by a mathematical approximation in the data-reduction process.     

The Askervein Hill Project: Wind-tunnel simulations at three length scales

Wind-tunnel simulations of neutrally-stable atmospheric boundary-layer flow over an isolated, low hill (Askervein) have been carried out at three different length scales in two wind-tunnel facilities. The objectives of these simulations were to assess the reliability with which changes in mean wind and turbulence structure induced by the prototype hill on boundary-layer flow can be reproduced in the wind tunnel, and to determine the relative impact of certain modelling approaches (surface roughness, model scale, measurement techniques, etc.) on the quality of the simulations. The wind-tunnel results are compared with each other and with full-scale data and are shown in general to model the prototype flow very well. The effects of relaxing the criterion of aerodynamic roughness of the model surface were limited to certain regions in the lee of the hill and were linked to separation phenomena.     

Problems of accuracies in combined terrestrial and statellite control networks

Summary The combination of terrestrial and satellite aided network observations requires hybrid models of two kinds: a hybrid functional model and a stochastic model being able to process the heterogeneous observations approapriately. An appropriate combination of stochastic information means to adjoin proper weights to the various types of observations on one hand and on the other hand to separate the relelevant internal accuracy from that accuracy which is affected by a number of network external influences. The first task can be overcome by the technique of estimating variance components of the individual observation groups, the second one can be handled by applying S-transformations to covariance matrices. The paper deals with problems of the hybrid stochastic model. Examples are given.