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Trebol is an epithermal vein system and a relatively new Radius project discovered during stream sediment and reconnaissance rock sampling within the Region Autonoma Atlantico Norte (RAAN) in northeastern Nicaragua. Prospecting work found notable amounts of free, visible gold in stream sediment and quartz float in two areas.
The epithermal veins at Trebol are exposed on a series of low-lying ridges- they are of typical low-sulphidation affinity and comprise banded quartz breccias and stockworks with visible gold noted at some locations. Trenches were excavated over a strike length of approximately 6km, and the limits of the mineralized system are still unknown. Below you'll find a chart of the selected trench sample highlights.
Trench Number |
Sampled Interval |
Weighted Average Au g/t |
TRSD-01* |
13.5 |
0.24 |
TRSD-02* |
10.4 |
1.34 |
TRSD-03* |
34.0 |
1.0 |
TRSD-04* |
35.25 |
4.91 |
includes |
8.35 |
17.6 |
TRSD-05* |
11.65 |
2.7 |
TRSD-06* |
10.0 |
0.93 |
TRSD-07* |
13.4 |
0.5 |
TRSD-08* |
12.65 |
0.75 |
TRSD-09* |
19.43 |
0.37 |
TRSD-10* |
9.0 |
0.37 |
TRSD-11* |
11.8 |
0.38 |
TRSD-12* |
11.0 |
0.29 |
TRSD-13* |
6.0 |
1.73 |
TRSD-14** |
22.0 |
0.57 |
includes |
6.0 |
1.0 |
TRSD-15** |
33.8 |
3.4 |
including |
15.0 |
6.1 |
TRSD-16** |
13.0 |
0.19 |
TRSD-17** |
20.0 |
0.87 |
*Refer to Press Release dated Oct 16, 2007 and April 7, 2008
**Refer to Press Release dated April 7, 2008
Trenches TRSD-01 to -03 are located in a broad, well developed stockwork zone whereas trench TRS-04, topographically lower, exposes a quartz/adularia banded vein with abundant visible gold associated with manganese and iron oxides.
Radius is currently drilling a series of diamond drillholes to test the sub-surface continuity of the gold grades observed in selected trenches and to give geological and structural information on the geometry and controls on mineralization. Approximately 8 holes are anticipated (approximately 1,000m of drilling) in this initial stage. The size of the mineralized system at Trebol is as yet undefined. The company believes that the broad widths of higher grade massive veins and lower grade stockworks as observed in the trenches may indicate potential for bulk-tonnage mineralization.
The prospect geology at Trebol was relatively unknown prior to drilling due to thick soil and vegetation cover. Mineralization drilled in all holes is associated with broad zones of well-developed banded quartz-adularia veins, stockworks and silicified breccias, typical of low-sulphidation epithermal systems, which correspond to the down-dip continuation of the mineralized zones sampled in surface trenches (see Trebol gallery for core photos). Textures generally show early multiple-stage brecciation, silicification and fracturing/annealing events which precede a later cockade textured, drusy, coarse-grained quartz mineralization.
Host rocks to mineralization is a tuffaceous sandstone/lithic tuff unit associated with strong sericite-clay alteration and pyritization which forms part of a transition zone to a footwall mafic volcanic unit of basaltic composition. The broad, shallow-to-moderately dipping tabular zones of alteration suggest a strong replacement/lithological control on mineralization. This represents a different mineralization style seen in Nicaragua in contrast to the typical narrow fissure quartz veins prevalent elsewhere.
Highlights from the first 5 holes are as follows:
|
Hole ID |
From
(m) |
To
(m) |
Interval
(m) |
Assay Au g/t |
Hole
Depth (m) |
|
| TRDH-08-01 |
12.19 |
35.3 |
23.11* |
1.51 |
61.87 |
| TRDH-08-02 |
28.95
35.4
36.57 |
35.4
36.57
50.29 |
6.45**
1.17
13.72 |
0.49
No recovery
0.71 |
123.44 |
TRDH-08-03
|
59.44
112.77 |
84.82
120.39 |
25.38***
7.62 |
0.44
1.37 |
138.68 |
TRDH-08-04
inc. |
3.3
5.25 |
24.38
15.5 |
21.08
10.25 |
1.44
2.55 |
45.41 |
TRDH-08-05
inc. |
6.09
6.09 |
59.5
25.9 |
53.41
19.81 |
1.35
2.89 |
77.72 |
|
The progressively weaker gold grades observed in TRDH-08-02 & 03 which intercepted the mineralized zone observed in TRDH-08-01 at progressively deeper levels, suggests that supergene processes are likely accountable for the generally higher grades seen in Trench 15 and TRDH-08-01, as similar pervasive epithermal veining and stockworks are observed in all three holes. The deeper intercept of 1.37 g/t Au over 7.62m in TRDH-08-03 from 112.77m to 120.39m is related to a shear zone in mafic volcanics, possible representing a basal feeder fault.
Hole TRDH-08-04 was collared approximately 1km to the north-east of section TRDH-08-01, 02, 03 and drilled at an inclination of -45 degrees to the south-east underneath the ridge in the vicinity of Trench 4 (35.25m at 4.9 g/t Au), located some 90m away. A zone of strong silicification and veining was intersected within the first 25m before passing into propylitised mafic volcanics, suggesting a gently dipping attitude to the mineralized zone. The interval assayed 1.44 g/t Au over 21.08m from 3.3 to 24.38m depth, with a higher grade intercept of 2.55 g/t Au over 10.25m from 5.25 to 15.5m.
Hole TRDH-08-05 was drilled some 150m N of TRDH-08-01 to test the depth continuity of mineralization seen in Trench 2 (10.4m at 1.3 g/t Au) and recently Trench 21 (17.1m @ 6.1 g/t Au). Highest grades are associated with massive banded quartz veins and breccias with 1-5% pyrite and black manganese oxides (up to 17.8 g/t Au 18.75 -- 19.81m). Weaker stockworks and silicified zones form broader envelopes of lower grade mineralization within the tuff and mafic volcanic sequence.
Drilling is continuing to test additional zones for geometry and near surface mineralization, and for deeper structural targets. Elsewhere on the property, soil sampling has identified several new trends of gold-bearing veins and stockworks associated with adjacent ridges located up to several kilometers away from the area being drilled. These new areas are being followed up by trenching and sampling.
Click Here to View Trebol Photo Gallery
Maps
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