Full text loading...
- ISSN: 0812-3985
- E-ISSN: 1834-7533
-
Discovery of the Eureka volcanogenic massive sulphide lens using downhole electromagneticsFN1
- Australian Society of Exploration Geophysicists
- Source: Exploration Geophysics, Volume 47, Issue ASEG-PESA 24th International Geophysical Conference and Exhibition: Special Issue on Case Studies, Sep 2016, p. 248 - 257
-
- 07 Sep 2015
- 18 Apr 2016
- 01 Sep 2016
Abstract
[
The Eureka massive sulphide lens forms part of the Stockman Project in north-east Victoria. Eureka was discovered in early 2013, combining the interpretation of two subtle downhole electromagnetic anomalies with a robust geological model, with additional support from short-wave infrared and structural modelling.
,The Eureka volcanogenic massive sulphide (VMS) lens forms part of the Stockman Project in north-east Victoria. Eureka was discovered in early 2013, heralding the first new VMS mineralised zone to be discovered at the project since 1979. Key drivers to the detection of Eureka included the combination of downhole electromagnetics (EM) and a robust geological model.
The lens is located 350 m to the north-east of the Currawong deposit, at a vertical depth of 360 m. Surface EM methods played a significant role in the discovery of the nearby Currawong and Wilga deposits during the late 1970s. Despite this, modern day airborne and fixed-loop transient EM (FLTEM) surveys failed to detect Eureka, most likely due to its depth, moderate conductance and loop-edge effects masking anomalies. The key component in discovering the lens was the interpretation of two subtle downhole transient electromagnetics (DHTEM) responses from 2012 exploration drillholes. These responses were further strengthened by structural and short wave infrared modelling, presenting a compelling multi-component drill target.
The lens was discovered soon thereafter, with a discovery intercept of 22.65 m at 1.2% Cu, 0.7% Pb, 3.9% Zn, 43 g/t Ag and 1.3 g/t Au.
]
ASEG