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Bodenmagnetik |
Aus Silbermine.at
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Mittels bodenmagnetischen Messungen entlang parallelen Messlinien (Profile) können ferromagnetische Erze wie Pyrrhotin und Magnetit lokalisiert werden. Nachdem Pyrrhotin häufig mit Gold und sulfidischen Erzen vergesellschaftet auftritt, so kann im Zuge von Prospektionsarbeiten das Auffinden von magnetischen Anomalien eine polymetallische Vererzung anzeigen. Silbermine Pichl (Unterzeiring)
Der "Kuckuck Pyrrhotin Erzgang" hat eine nachgewiesene Länge von 230 m. Im Messprofil P.130 beträgt der Differenz zwischen Maximalwert und Minimum 1.200 nT (Nanotesla) und zeigt eine bedeutende (goldführende ?) Pyrrhotinvererzung an. Nachdem in der Fortsetzung der Streichrichtung im benachbarten Klumgraben ebenfalls starke magnetische Anomalien gemessen wurden, könnte es eventuell sein, dass der "Kuckuck Pyrrhotin Erzgang" eine Gesamt-Erstreckung von 800 m aufweist. Bodenmagnetische Messungen am Oberzeiringer Erzberg :Die nachfolgenden Grafiken stammen aus dem Bericht der Firma Geocomplex A.S.
Im Messprofil 4M und 5 M wurden erhöhte magnetische Anomalien festgestellt. Dies deutet auf (goldführenden ?) Pyrrhotin, vergesellschaftet mit Sphalerit (Zinkblende). Im Oberzeiringer Ostfeld tritt Sphalerit häufig mit Pyrrhotin vergesellschaftet auf.
Bericht der Geocomplex A.S. über die bodenmagnetischen MessungenProgress report During May – June, 2006 the Geocomplex a.s. Bratislava has carried out the magnetic survey at Oberzeiring – Hoanzl area after Consultancy Agreement signed by both sides. Most of the magnetic profiles have been located to the NNE from Snack station Hoanzl. At this area in question a mineralization zone is present, called by you “Martin – Erzgang”. Nine magnetic profiles have been located, surveyed and measured within this zone. They are /from NW to SE/: 6M, 4.2M, 4.1M, 5M, 1M, 2M, 3M and 3.1M. The orientation of these magnetic profiles is SW-NE; step of [T] measurement was 5m. The local normal magnetic field [Tn] of total magnetic vector T represents here value of 47 870 nT. Using this value for determination of magnetic anomalies intensity, the important magnetic anomalies DT {DT = T – Tn} have been found along many profile lines. At the profile 5M (10 m from the geoelectric IP profile D) the magnetic anomaly has been measured between 20 and 50 stations, reaching DT maximum at station 40 (DT = +270 nT) On 4M profile (located 40 m from profile D) two magnetic anomalies have been found: between station 10 and 44 (DT = +70 nT at station 30 and stations 70 – 120 (DT = +130 nT at station 110). These significant magnetic anomalies reflect very probable a mineralization zones, containing also ferromagnetic minerals (pyrhotine, magnetite). At the so-called “Pipe” area (we named this area according to the shape of magnetic anomaly), at the end of profile 6M, at Pipe 1 and Pipe 2, the significant magnetic anomalies have been also found. Very intensive anomaly has been measured on profile 6M at NNE end of it, between stations 190-220 with expressive negative part on NNE side of anomaly (DT = minus 450 nT). He positive part of this anomaly reaches maximum at station 214 (DT = +240 nT). The shape of these anomaly correspondents to steeply dipped mineralization at Pipe profiles (with ferromagnetic minerals) near the surface. In the area of the SSW part of the profile 4.1M between stations –90 and –105 and profile 4.2M between stations –70 and – 105 including the profile 11M between stations –100 and –120, profile 11M++105 the important magnetic anomalies with high DT have been found too. At the anomalous part of geoelectric (IP) profiles E and B have been measured no magnetic anomalies. It means that in this sub-are no ferromagnetic minerals occur within polymetalic zone. In the extreme west of the area in question, W of Snack station Hoanzl, the magnetic profile 7.1 M has been located and measured. The geoelectric (IP) profiles 2, 4, and 5 show an expressive IP anomalies but no magnetic anomaly has been measured there (absence of ferromagnetic minerals). CONCLUSION The performed magnetic survey in Hoanzl area has found several important magnetic anomalies corresponding to the polymetalic mineralization zone with presence of ferromagnetic minerals. From present results of IP and magnetic surveys, we suggest to continue with geophysical exploration in the area of Oberzeiring Hoanzl. Compiled by: Dr. Jozef Hricko, Project Manager for Geocomplex a. s. Bratislava 20.06.2006 Siehe auch |
