Agriculture,soil erosion and fluvial processes in the basin of the Jialing Jiang (Sichuan Province/China)

The Red Basin is a tectonic structure. Master stream is the Jialing Jiang, the most important tributary of the Chang Jiang in this area. The landforms are a cuesta landscape, climate is subtropic. Under irrigation 3 harvests of grain are possible. Small farms dominate. The region is overpopulated. Industrialization is in its infancy. Intense deforestation, extension of arable land and increasing grazing of animals on slopes and scarps of field-terraces have caused a change in precipitation, water regime and discharge of stream-borne material in the catchment area of the Rating Jiang. This differs distinctly from the neighbouring rivers and can be compared with the rivers of the loess areas of N China. Severe soil erosion destroys arable land at a growing rate. Unlike the loess area in the Red Basin, there is only a thin layer of soil which can be regenerated only over a long period of time. Afforestation and hydraulic engineering are intended to retard soil erosion. More effective would be diminished intensity of land use and the supply of organic material from plant decay — hitherto used as fuel - for soil. formation. But lack of employment outside agriculture prevents more extensive land use. So the destructive intervention into the ecosystem reflects the strain of increasing population in the stage of beginning industrialization. *** DIRECT SUPPORT *** ABI02050 00004     

Molecular bands of supernova 1987A

We have re-investigated the earlier calculations of Sharp and Höfflich (1989) for the first overtone of CO as observed in SN 1987A. The cooling effect of CO has been included in the models. We found a similar but slightly lower CO-enrichment. The sensitivity of the band structure on temperature is also demonstrated.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

Comment on the paper by S. Kielbassa and H., Duddeck: Stress — Strain fields at the tunnelling face — Three-dimensional analysis for two-dimensional technical approach

Rock Mech. Rock Engng. 24 (3), 115–132, 1991.     

Age and evolution of scheelite-hosting rocks in the Felbertal deposit (Eastern Alps): U-Pb geochronology of zircon and titanite

U-Pb isotope analyses of zircon and titanite extracted from different rocks of the Felbertal scheelite deposit yield the following information: (1) An age of 593±22 Ma (2) is obtained for zircon crystallization in the scheelite-bearing matrix of an eruption breccia in the western ore field. (2) Discordant zircons from an elongated, up to 8 m thick scheelite-rich quartzite body in the eastern ore field give an upper intercept age of 544±5 Ma. This quartzite contains a laminated, fine-grained scheelite mineralization. (3) Zircons from a small granitoid intrusion of the western ore field reveal an age of 336±16 Ma, and concordant titanites document an age of 282±2 Ma for Variscan amphibolite facies metamorphism. Both events, granitoid intrusion and later metamorphism caused ore re-mobilization, including the formation of yellowish fluorescent (molybdo-) scheelite porphyroblasts. (4) For a narrow lamprop-1hyric dike in the western ore field, a concordant titanite age of 283±7 Ma is obtained. This age is identical with the titanites from the amphibolite facies metamorphic intrusion. Tiny scheelite grains were tapped by the dike from pre-existing scheelite mineralizations in the truncated host rocks. (5) Alpine metamorphism at 31±4 Ma did not exceed lowermost amphibolite facies conditions, and it caused scheelite re-mobilization on a minor scale only, producing bluish fluorescent porphyroblasts in quartz veinlets and veins, as well as bluish fluorescent scheelite rims around older scheelite grains. Moreover, crosscutting Alpine fissure fillings show bluish fluorescent, inclusion-free scheelite. (6) The preservation of Variscan titanites, the absence of Alpine titanite growth, and the large degree of Variscan scheelite re-mobilization demonstrate that amphibolite facies metamorphism in the Felbertal area has a Variscan age. This result clearly documents Variscan tectono-metamorphism to be the dominant event, instead of the hitherto surmised Alpine metamorphism. This multi-stage evolution of the Felbertal ore bodies corroborates the view that tungsten deposits are conditioned by several succeeding thermal events, leading to a series of stages that ultimately produce high-grade scheelite concentrations. These high-grade ores predominately occur along shear zones of different age, accompanied by the formation of large volumes of low-grade scheelite mineralizations along host rock foliations and quartz veinlets and veins.     

The spa Deutsch-Altenburg and the hydrogeology of the Vienna basin (Austria)

 Some years ago the thermal water wells of the spa Deutsch-Altenburg were considered the result of a local water circulation. Extensive measurements of the water chemistry, trace elements, and environmental isotopes combined with drillings in the river bed of the Danube resulted in the indication of a key position of the mineral thermal wells of Deutsch-Altenburg for the groundwater circulation in the entire Vienna basin. The proof of this fact demanded the inclusion of the complicated geological position of the basin into the argumentation. The historical background of Bad Deutsch-Altenburg is the Roman municipium Carnuntum. During the reign of the Roman emperor Marc Aurel (161-180 A.C.) Carnuntum became the largest Roman municipium northeast of Rome with about 50 000 inhabitants covering the areas of present-day villages Petronell and Deutsch-Altenburg due to its strategic and trade position. The town was totally destroyed during the era of "migration of nations." The land surface was farmland or meadows. The first document concerning the thermal water of Deutsch-Altenburg is an expertise of the medical faculty of the University of Vienna (1548). During the siege of Vienna by the Turkish army under Kara Mustafa (1683–84) Deutsch-Altenburg was again, destroyed. It was only at the end of the 19th century that the modern installation of the spa began. The healing thermal water with the highest content of sulfur in Austria made Deutsch-Altenburg one of the most well-known spas in the country. The archaeological excavation of Carnuntum is the largest in Austria. Received: 6 October 1995 · Accepted: 13 November 1995     

Lateral dispersion of low-energy protons precipitated in the auroral zones

Through the use of a Monte Carlo type calculation, the lateral dispersion of a fine proton beam of given energy and pitch angle in an atmosphere of given exospheric temperature is investigated. It is found that this lateral dispersion may be estimated by using a simple analytical expression.