Westminster - Tennant Creek, NT
(MLC511, A25952 - Truscott 100%)
Westminster Project
Truscott's Westminster project area lies just west of the Tennant Creek Township and covers more than 1.2 kilometres strike length of mineralised ironstone outcrop and subcrop containing historical shallow high grade gold workings. Truscott's Westminster Project includes the Wheal Doria licence MLC511 and the Big Ben, Peter Pan tenement A25952. These`are on vacant crown land and lie on the eastward extension of the Chariot-TC8 line of mineralisation and contain high grade gold workings at surface, in ironstone within Warramunga host sediments. Combined recorded production from these deposits totals approximately 3,500 ounces of gold at an average recovered grade of 36g/t Au.
Truscott is targeting down-plunge extensions of these near-surface workings and associated alteration zones, using an exploration model based on the White Devil orebody, which produced over 750,000 ounces of gold at an average grade of 14.6g/t Au to 1999.
The main gold deposit at White Devil did not reach surface but was discovered at depth, adjacent to old surface workings on a small but high grade mineralised pod at Black Angel. It is also noteworthy that the Chariot Gold Mine, less than 9 kilometres west from Wheal Doria along the line of lode and 2.2 kilometres north of Arcadia, was first drilled in 1972 by the NT Geological Survey but only minor gold and copper mineralisation was intersected at that time. It was much later, in 1998, that Normandy Tennant Creek Pty Ltd was successful in discovering the orebody which was then mined from 2003 by Giants Reef Mining Ltd.
Exploration Developments
A compilation of a detailed database of previous mineralisation, geological, geophysical and structural data, including records of mining and drilling which were previously unknown has demonstrated the presence of major alteration systems with high-grade gold mineralisation, and has confirmed that the project potential remains inadequately tested by previous exploration.
Results received from an initial orientation rock chip sampling programme of ironstones and host sediments, selected to characterise the multi-element geochemical distribution at Westminster (Figure 7) have shown gold values to 9.97g/t Au and copper values to 2.52% Cu from sheared and altered sediments of the Warramunga group, the predominant mineralised host in the Tennant Creek goldfield. Initial interpretation of the multi-element data indicates that there is a zoning from gold-rich near the eastern end of the project, to gold-copper±Co±Sb further to the west. At Wheal Doria, central to this trend, elevated base metal values of 0.42% Pb, 0.18% Zn and 17.6g/t Ag were also recorded. Further work is planned, to better understand this metal zonation, mineralisation style and alteration assemblages.
Figure 7: Exploration Results, Westminster Project, Tennant Creek.
Much of the previous exploration and drilling at Westminster was targeted on a magnetic survey conducted in 1936-37 by AGGSNA (Aerial Geological & Geophysical Survey of Northern Australia). Four vertical field anomalies were defined by the survey on a wide-spaced 60m x 15m grid. To improve on this 70 year old data, Truscott completed a 50m x 5m proton precession ground magnetometer survey, with data processing by geophysical consultants SGC (Figures 7, 8). This greatly improved modern data has allowed interpretation of significant additional structural and anomaly detail, considered to be very important in orebody targeting. Review of previous drilling shows that old drill locations were not optimal for testing the true positions of the magnetic anomalies, as revealed by the Company's new survey.
Significant advances have also been made in compilation of a detailed database of previous mineralisation, geological, geophysical and structural data, including inspection of remaining diamond core. Where possible, hole collars were located in the field and surveyed by DGPS or GPS instrumentation, and all down-hole data has been migrated to the current NT datum in GIS format, from this work significant intercepts have been identified (Figure 8).
Figure 8: Significant Historical Drill Intercepts and Ground Magnetics, Wheal Doria
In the eastern sector of MLC511, 5m at 10.94g/t Au was intersected in TCRC13 over 10 years ago but never followed up. This correlates with an intersection of 3.0m at 10.50g/t Au, including 1m at 26.3g/t Au, recorded 125m east in a magnetite rich zone in altered sediments in Explorer 45 DDH5, drilled in 1979 just outside MLC511. The zone between these high-grade results remains undrilled although other significant intercepts occur nearby.
Most of the old drilling was close to the Wheal Doria mine, including NMDDH1 which intersected 5.0m at 39.42g/t Au from 89.1m downhole and was followed by deepening of the shaft to 71m in 1953. Other significant intercepts nearby include 2m at 8.27g/t Au in TCRC02.
Between Wheal Doria and Peter Pan, WDDDH1 intersected 1.83m at 11.3g/t Au from 149.8m, within a broader mineralised zone of 24.7m at 1.20g/t Au from 138.8m downhole. This hole was drilled in 1960 targeting AGGSNA anomaly 1, which remains only partly tested as interpreted from Truscott's newly acquired magnetic survey data. Some 750m west of WDDDH1, BBDDH1 was drilled in 1959 at Big Ben, to test AGGSNA anomaly 4. A broad zone of intense carbonate alteration recorded 23.3m at 0.70g/t Au from 208.3m to end of hole. This hole failed to reach target and a wedged secondary hole was drilled and recorded 37.5m at 0.57g/t Au from 210.2m downhole. Both holes failed to intersect any magnetic material and the anomaly remains unexplained and untested. The alteration is similar to that in the hangingwall immediately above the TC8 orebody, less than 2.5 kilometres to the west.
Clearance for both exploration and mining activities on MLC511 and A25952 has been received from the Aboriginal Areas Protection Authority, and a Mining Management Plan for Westminster MLC511 has been approved by the NT Mines Department. Truscott has commissioned a detailed ground gravity survey, over the same grid as the recent magnetics, to provide further updated geophysical targeting for planned diamond drilling in the December 2007 quarter.