Tracer Tests in flooded underground mines
Tracer tests are a common means to investigate the hydrogeological conditions in the hydrosphere. Nevertheless, only few successful tracer tests in flooded underground mines have been described. In two flooded German underground mines tracer tests with club moss spores (Lycopodium clavatum) and microspheres had been conducted by the use of the LydiA technique. Both times, effective velocities between 1 and 8 m min could be calculated and a good hydraulic connection between the mines’ parts investigated could be proved. Lycopodium Apparatus (LydiA)
Hydrogeochemie, Wärmehaushalt und Strömung des Flutungswassers einer untertägigen Erzgrube
Die Erzgange der Polymetallsulfidlagerstatte Freiberg (Sachsen) wurden seit dem 12. Jahrhundert abgebaut. Das Hauptinteresse galt zunachst dem Silber aus dem Galenit, spater hauptsachlich dem Blei und Zink. In der letzten Betriebsperiode drang der Bergbau in der „Freiberger Himmelfahrt Fundgrube“ bis in 700 m Tiefe vor. Er hinterlies zum Zeitpunkt seiner Flutung um 1970 ein Hohlraumvolumen von ca. 2,6 Mio. m3 bis zum tiefsten wasserabfuhrenden Hauptstolln (Rothschonberger Stolln) in ca. 220 m Tiefe. Seit dem Uberlauf des Grubenreviers haben sich die hydrogeochemischen Eigenschaften des Flutungswassers stark geandert. Aus der Zusammenfassung historischer Daten und der Auswertung neuer Ergebnisse wird Bilanz uber die Entwicklung des Flutungsraumes gezogen. Es lassen sich Ursachen geochemischer Signaturen, eine Modellvorstellung von der Entwicklung des Stromungs- und Temperaturregimes und damit neue Aspekte fur die Bewertung bzw. Nutzung von Flutungraumen ableiten.
Prevalence of lice on dairy cattle in England and the bordering counties of Wales
A postal questionnaire was used to collect information on the prevalence of lice on cattle on a random sample of dairy farms in England and the bordering counties of Wales. Replies were received from 1040 (52.8 per cent) of the 1970 farms which were mailed. Fifty per cent of farmers reported having ever seen or suspected lice in their herds and 29 per cent reported possible infestations in the winter of 1996/97. Visits were made to 24 farms in the south west of England during February 1998. Twelve of the farmers said that they had seen or suspected lice in their herd since October 1997, and that lice were more frequently observed on the adult cattle. However, examination revealed lice on 18 of the 24 farms, and adult cattle were the least likely group to be infested.