| |
Projects |
Included Licenses |
Summary & Overview |
Tanzanian Royalty Exploration Interest |
Geology |
Drilling |
Future Activities
Shinyanga Property
Summary & Overview
- The project area consists of approximately equal proportions of greenstone and granite.
- BLEG soil sampling identified strong ENE trending gold anomalies in the southwestern and south-central portion of the project area, within metavolcanic rocks.
- Trenching succeeded in intersecting a zone of 2.12g/t Au over 1.53m.
Regional Geology :
The license is situated amongst the scattered greenstone units of the Shinyanga greenstone belt, some 25km to the north of the Nzega greenstone belt. Principal rock types include metabasalt with quartz veinlets, BIF, granite and diabase dykes. Greenstone cover is estimated at 50%, with the balance comprising granite. There are also known kimberlite occurrences within this project area.
Principal Structures :
Towards the S, the metabasalts appear to have a conjugate schistosity/cleavage to suggest a general NE to ENE trend. Granite outcrops along the southern boundary of the greenstone domain also show a weak foliation oriented towards the NE and dipping vertically.
In the northern portion of the license, saprolite schist has a measured schistosity trending NE, and dipping steeply to the NW. A suite of N-S trending dykes can be found cutting chert/BIF/saprolite schist outcrops near the NW boundary of the license.
Geology of the Prospecting Areas :
In the southern portion of the license, the bedrock consists of metabasalt with quartz veinlets. Several thick massive chert outcrops occur further towards the east. The northern portion of the license is covered by rolling hills with abundant chert/BIF/argillite debris as angular pebbles and cobbles, rarely boulders, but with few outcrops. Granite outcrops near the eastern boundary of the license comprise coarse to very coarse-grained massive unfoliated feldspar-porphyritic biotite granite. Dykes of this same granite trending N-S can be found cutting the chert/BIF/saprolite schist outcrops examined near the northwestern boundary of the license. One known kimberlite exists on the NE boundary of the license.
Reconnaissance Sampling:
BLEG soil sampling on a 400m x 400m grid (October 2003) reported 20 anomalous values (≥6ppb) with the highest value being 16ppb. The majority of the anomalies form a cluster in the southwest to the south-central portion of the license on the mafic metavolcanic rocks (basalt), forming an ENE trend.
Mini BLEG soil sampling follow-up on a 200m x 200m grid (January 2004) reported first order anomalies at ≥10ppb Au, and second order anomalies ≥4ppb Au. The highest value is 26ppb Au. Using these thresholds, 3 broad NE trending anomalies were defined, each one being approximately 1km long and 500m wide.
Quartz debris sampling (June 2004) was carried out where soil cover is non-existent to very thin, within the anomalous areas defined by previous soil sampling. Such areas are covered with significant rock and vein quartz debris, and represents about 65% of the soil anomaly covering the northern and western parts. A total of 98 samples were collected along a series of traverse lines and within-line spacing of 50m. Results ranged from 0.2g/t to 1.1g/t Au.
Four trenches were excavated (September 2004) directly beneath areas defined by anomalous quartz debris samples. A single trench (SH130TR02) intersected an alternating sequence of metabasalt and metadiorite with a strong foliation and quartz veining along the contact zones. The quartz veins are typically thin being less than 20cm, but contain high grade gold intersections with selected grab samples carrying up to 65g/t Au. Re-sampling of the trench, taking true width channel samples along the best zone in the south-facing sidewall, revealed the following intersections:
|
Footwall diorite: |
|
0.5m channel sample |
|
0.03g/t |
| Footwall basalt: |
0.5m channel sample |
0.49g/t |
| 15cm quartz vein:
| 15cm channel sample |
10.30g/t |
| 30cm foliated basalt: |
30cm channel sample |
0.39g/t |
| 8cm quartz vein: |
8cm channel sample |
10.30g/t |
| Hanging wall basalt |
0.5m channel sample |
1.02g/t |
- A biogeochemistry sampling program was initiated in September 2004 over the western portion of the PL. This area is overlain by mbuga cotton soils. The program was conducted to try and extend the existing BLEG soil anomalies westward. 130 samples were collected at 25m intervals along lines 400m apart.
Two zones of BGC anomalies are clearly evident on a 285 degree trend. This extends the BLEG anomaly area westward increasing the targets to 5. The BGC anomalies have a high level of support for Au in terms of certain pathfinder and non-pathfinder elements. The N-S trend also hosts anomalous Au values and numerous supporting elements. Both trends provide ideal targets for first-pass regional RAB drilling.
Geophysics:
A government airborne magnetic program (1987) suggests that the southern metabasalt domain over the soil anomaly is trending ESE. This does not necessarily contradict the structural measurements (ENE/NE), as the magnetics are likely to indicate the overall outline of the mafic rocks, whereas the schistosity/cleavage may not be parallel to bedding, or to any bounding faults that may be present.
Drilling
RAB Drilling Program:
RAB drilling commenced in May 2005 to test the two BGC anomalies and the three BLEG anomalies. A total of 14 RAB fences were drilled totaling 492 holes giving a combined meterage of 7,247m. The RAB program identified three broad zones of Au mineralization known as the Western, Central and Eastern Zones
Click to Enlarge:
Anomalous Au zones and specific target areas identified by RAB drilling. Red triangles represent anomalous BGC samples.
Western Zone :
This is a weakly-defined zone of mineralization, with anomalous values ranging between 0.21 -- 0.38 g/t Au. This zone would appear to have an N-S strike extent, judging by the low-order Au intersects along drill fences K and L. Elevated Au values may well account for the anomalous BGC samples.
Central Zone :
This is a well-defined zone of mineralization with anomalous values ranging between 0.22 -- 1.87 g/t Au and good strike continuity towards the NW. Au intersects were achieved along drill fences G and H in addition to closer spaced cut lines, which formed part of the follow-up drilling.
Eastern Zone :
Anomalous Au values (with a peak of 5 g/t over 3 m) were intersected along a single drill fence (fence A). There was limited support for this in the adjacent closer spaced fences.
The continuity of anomalous Au values in the Central Zone, despite generally low numbers, but with good lateral support, was sufficient to justify further drilling in this area. Similarly, the higher-grade intersects which define the Eastern Zone, would also qualify for further follow-up drilling. The significantly lower Au values, in addition to the scattered nature of anomalous drill intersects in the Western Zone, does not warrant the need for follow-up drilling there.
Follow-up RC Drilling Program:
A 16 hole (784m) RC Drilling program was conducted in January 2006. 316 samples were collected and submitted for Au analysis. Results are summarized as follows:
Eastern Zone :
Two holes, SHRC-008 and SHRC-009 were drilled to test the mineralization extent of the 5g/t intersection of the earlier RAB program. Results were discouraging with the highest value being 0.03 g/t.
Central Zone :
Fence HW: (Boreholes SHRC-10, 11 and 12)
Boreholes 10 and 11 intersected thin zones of anomalous gold in slightly epidotized basalt with minor quartz veins. Borehole SHRC-12 primarily intersected a barren quartzite with barren basalt towards the end of the hole.
Table 1: Best assay results RC Phase 2 drilling.
Fence H: (Boreholes SHRC-13 and 14)
These two boreholes have anomalous gold intersections throughout the majority of the holes within a well foliated, and in parts sheared basalt.
Fence HE: (Boreholes SHRC-15 and 16)
Boreholes SHRC-15 and 16 intersected thin zones of anomalous gold in basalt.
Fence G: (Boreholes SHRC-17 and 18)
Boreholes SHRC-17 and 18 intersected moderate zones of gold mineralization within basalt containing thin zones of quartz veining in close proximity to intrusive diorite sills (Table 1 above) These boreholes have the highest grade intersections of 2.61g/t and 1.60g/t over one meter.
Fence GW: (Boreholes 19 and 22)
Borehole SHRC-19 was drilled under a silcrete palaeochannel to intersect anomalies along the strike of a RAB intersection of 0.25 g/t at the end of the hole in SHRB-183. The hole unfortunately remained in silcrete deeper than expected. The silcrete did appear darker in colour than usual suggesting that a weathered iron-rich (gold bearing) zone may have once have been present. A second hole SHRC-22 was drilled at a steeper angle intersecting the gold zone from 47 to 52 m.
Fence GE: (Boreholes 20 and 21)
Two holes were drilled intersecting thin (1m) zones of anomalous gold mineralization with the highest value being 0.24 g/t.
From the drilling it is evident that the Central Zone is conducive to gold mineralization, albeit of low grade. It appears that there are two zones of gold mineralization, one thick low grade zone found on section H (boreholes SHRC-13 and 14), and one thinner but better grade zone on fence G (boreholes SHRC-17 and 18).
Determining the dip and strike of the zone/s is tricky but it appears currently that the mineralization dips to the west at a moderate angle of approximately 50º. This can be determined from a section of Fence G. In cross sections HW, H and HE, the two thick gold intersections of boreholes SHRC-13 and SHRC-14 are not duplicated on the sections to either side. However, the mineralization in the top of holes SHRC-15 and 16 on Section HE could be the up-dip, basal portion of this mineralization. This supports the dips found on section G. The strike is however more problematic and can either be close to the north-south sections H and HE, or NW-SE on sections G and GE.
Future Activities
RC drilling indicates that this license has an affinity for gold mineralization, albeit at the moment the grades appear sub-economical. Before a decision is made on returning the PL to the vendor, an IP survey will be conducted over the Central Zone to see if the drilling has not missed more conductive targets at depth and between the gaps.
| |
