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Summary & Overview |
Tanzanian Royalty Exploration Interest |
Geology |
Geology of the Prospecting Areas
Kigosi Property
Summary & Overview
The total land area covered under the Kigosi Project Area includes multiple individual Prospecting Licenses. These licenses are situated in the northern part of the Kigosi Game Reserve located in the Kahama and Bukombe Districts of northwestern Tanzania.
Qualified Person
The technical information contained herein has been reviewed and approved by John Deane, President, Tanzanian Royalty Exploration Corporation Limited, a qualified person as defined by NI 43-101. He has an M.Sc. from the University of Cape Town (1993) and is a registered scientist with SACNASP (Reg. 400005/05).
An option agreement was signed between Ashanti Goldfields Cayman Limited ("AngloGold Ashanti") and Tanzanian Royalty Exploration Corporation in August 2003 to work on the PL's. AngloGold Ashanti commenced fieldwork on 1st April 2004 following receipt of an exploration permit from the Ministry of Wildlife and Tourism. Much of the documentation below is taken from extracts from various AngloGold Ashanti reports written during the period they operated in the area. Tanzanian Royalty entered into a Purchase and Sale Agreement with Ashanti Goldfields Cayman Limited dated September 26, 2006 for the repurchase of its rights to the Kigosi property, including all related camp and equipment, along with the purchase of a non-associated property, the Dongo, from Ashanti in a transaction valued at US$900,000.
AngloGold-Ashanti completed the following work during the option period:
- 8600 line/km of high resolution airborne magnetic data.
- gridding over selected areas.
- geological and regolith mapping of approximately 30% of the Project Area.
- 5855 soil, 40 termite, 60 pit, 157 trench, 11 stream and 277 rock chip samples were collected and analyzed.
- 433 soils taken on the Bungoni Prospect but submitted for analysis by Tanzanian Royalty.
- 364 soils taken on the Luhwaika East Prospect but submitted for analysis by Tanzanian Royalty.
NE, NW and E-W trending magnetic lineaments have been identified by a detailed geophysical assessment of the high resolution aeromagnetics. Of particular significance are the NNW-trending faults, which are parallel to the major Muhama Dislocation, a locus for extensive gold mineralization that joins up Golden Pride Mine with the Miyabi gold occurrence and the Tulawaka Mine.
A favorable structural setting, and very encouraging grab sample results along a well-defined lineament, called the Kigosi Lineament, has ranked this project area as a key exploration asset. There are currently three areas of interest along this lineament in the Kigosi Project Area, the Igunda and Luhwaika Prospects that have artisinal workings, and the Bungoni Prospect. AngloGold-Ashanti have also identified two further areas of interest, the Luhwaika East Prospect and the Msonga Prospect. Grab samples collected proximal to artisinal pits at the Luhwaika workings at Kigosi yielded values in the range of 5-10 g/t up to 233 g/t Au.
Tanzanian Royalty is now the sole operator on the Kigosi Project Area. The company has secured an all year permit to conduct exploration in the area and plan the following short-term exploration program that should be complete by the end of 2007:
- A full analysis of the AngloGold-Ashanti data (complete).
- Submit soils for analysis not submitted by Anglo (complete).
- Update the geology maps in the immediate vicinity of the Luhwaika and Igunda workings (complete).
- Conduct IP traverses on 400 m spaced lines across the Luhwaika and Igunda area (in progress).
- Plan a first phase 5000 m RC drilling program across the Luhwaika and Igunda workings based on the IP and geochemical results.
Qualified Person
The technical information contained herein has been reviewed and approved by John Deane, President, Tanzanian Royalty Exploration Corporation Limited, a qualified person as defined by NI 43-101. He has an M.Sc. from the University of Cape Town (1993) and is a registered scientist with SACNASP (Reg. No.400005/05).
Regional Geology:
The Kigosi Project Area is host to two of the Nyanzian greenstone belts within the Lake Victoria Goldfields of NW Tanzania. These are the Kigosi-Miyabi granite-greenstone terrain situated in the southeast of the Project Area and the Ushirombo greenstone belt in the northeast of the Project Area. This Kigosi-Miyabi greenstone belt hosts gold workings at Luhwaika and Igunda at Kigosi, and further southeast lies the Miyabi Gold Project owned by Golden Eagle Resources. Luhwaika and Igunda have been worked on by local artisanals for decades. These workings occur intermittently along a strike length of ~4.8 kms. They are NW-SE trending and are located less than 5km from the WNW-trending major Kigosi -- Haneti litho tectonic boundary. This boundary is regarded as being an important regional control for gold mineralization and has been compared to the Cardilac Fault Zone in the Abitibi Greenstone Province of Canada.
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The majority of the greenstones identified to date consist of mafic volcanics of basaltic composition. The granites form the main rock constituent and have been separated into 5 types based on main mineral constituents and aeromagnetic signatures. The entire rock package, except for the Ushirombo belt, has a northwest trend with the main geological contacts having a strike of approximately 315º. A swarm of NE trending Bukoban dykes crosscut the granite. These dykes have been displaced by 340º trending structural zones displaying a dextral sense of movement.
One of these structural zones is the main gold-hosting lithostructure, the Kigosi Lineament. It traverses across granite, granite-greenstone contacts and reactivated lithologic boundaries. The lineament is clearly visible on the total field intensity magnetic map forming a magnetic low. AngloGold-Ashanti geologists have mapped in a gold corridor referred to as the Kigosi Gold Corridor that is spatially related to this structure.
Strongly altered quartz-sericite schist after granite, altered granite-mafic volcanic rock contacts and sheared mafic volcanic rocks with impregnations of tabular and shear-laminated quartz ribbons are the most common rock units within the Kigosi gold corridor. Recent mapping has also revealed outcrops of deformed mafic volcanic rocks, BIFs and sub-crops of intermediate to mafic volcanic rocks which were previously not documented from the area. The extent and persistence for the mineralized and associated alteration zones within the shear have not fully been established.
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Principal Structures:
The Luhwaika and Igunda workings exposed gold-hosting and associated alteration zones similar to those known from other well-endowed mesozonal gold systems in the world. Apart from the known gold mineralization, there are other favourable controlling factors that suggest that the Luhwaika -- Igunda system could host a multi-million ounce deposit:
- Major fluid conduit systems: crustal-scale lineaments coincident with the major Kigosi - Haneti terrane boundary (the Kigosi Shear System).
- Deformed and strongly altered granite along the Kigosi Lineament: granite not only acted as a rigid body against which greenstones deformed, but became deformed itself becoming the focus for fluid migration which led to the strong sericitization, silicification and sulphidation.
- Geometrical orientation of the host terrane: they are at high-angles to the orientation of the maximum far field stress regime.
- Tectonic reactivation of the host terrane: comprising granite-greenstone blocks/slices displaced along NE-SW trending faults.
Geology of the Prospecting Areas:
Luhwaika and Igunda gold occurrences.
Local Geology:
The total strike length of the Kigosi Lineament taken from the airborne magnetics is 35km. The total length of the known gold occurrences (referred to as the Kigosi Gold Corridor) is currently 4.8 kilometres.
The Kigosi Gold Corridor is bounded on either side by strong 305º trending shear systems that are sub-parallel to the Kigosi -- Haneti tectonic boundary. This shear system is referred to as the Kigosi Shear System and has an inferred sinistral sense of movement. This inferred movement would allow the Kigosi Lineament to dilate between the bounding shears allowing deep seated fluids to alter and mineralize the lineament within the area referred to as the Kigosi gold corridor. It is within this gold corridor that the two artisanal mining sites, Luhwaika and Igunda are located. The artisinal sites are separated by a 2.5 kilometre wide swath of mbuga (overburden) known as the Luhwaika - Igunda gap.
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The Luhwaika artisinal site:
The Luhwaika workings are the largest in the Project Area with sporadic artisanal activity spread over a distance of approximately 1,200 metres. The gold mineralization is spatially related to a granite/greenstone contact. At Luhwaika artisinal activity has targeted a zone of quartz stockwork granite and quartz sericite schist.
From the productive shallow artisanal shafts, it appears that at least two sub-parallel zones exist. This is confirmed by the AngloGold-Ashanti soils data that extend the Luhwaika mineralization to over 3.3 kilometres along strike. The soil data indicate a strong relationship between the granite contact and the gold mineralization. Grab samples taken at Luhwaika have returned values up to 194 g/t. A spatial distribution analysis of the data suggests that the dominant trend on the gold mineralization at Luhwaika is 340º which parallels the Kigosi Shear Zone.
Proximal wall rock alteration includes silicification, sericitization, sulphidation (predominantly pyrite) and local zones of strong hematization. These zones are separated by alternate outcrops of quartz stockwork veined biotite-granite containing up to 15% pyrite disseminations.
The Igunda artisanal site:
The present strike of the Igunda workings is 322º and they are approximately 300 metres in length. These workings have exploited a thin (one meter) quartz vein within mafic volcanics and have a similar strike to the Luhwaika workings but a steeper almost vertical dip. Grab samples from these workings have returned values up to 50.32 g/t.
Geochemical Sampling:
A review of the AngloGold-Ashanti Luhwaika-Igunda soil geochemistry data was undertaken with particular emphasis being given to the following:
- Separate the Luhwaika and Igunda soil geochemistry data into 2 separate data subsets, and perform a routine statistical analysis on each subset.
- Perform a grade distribution analysis for each data subset, and determine percentile cut-offs unique to each subset i.e. 80th, 90th, 95th and 99th percentile cut-off values.
- Perform a spatial distribution analysis using SpaDis for each data subset, and attempt to identify higher grade gold trends.
- Perform a gridding/contouring routine on each data subset, based on simple kriging, and a search ellipsoid determined by the spatial distribution analysis, in addition to known geological parameters i.e. measured kinematic data derived from exposed "reef" in artisinal workings and exploration trenches.
- Combine the two gridded/contoured data sheets onto a single plan, and attempt to note any gold trends that may link both the Luhwaika and Igunda prospects.
The table 1 below is a comparison of the basic statistics for both the Luhwaika and Igunda soil geochemical data -- as treated separately.
Statistical comparison - Luhwaika & Igunda geochem data.
| Statistic |
Luhwaika Grid |
Igunda Grid |
| No. of samples | 504 | 824 |
| Maximum Value (Au ppb) | 173 | 67 |
| Minimum Value (Au ppb) | 2 | 2 |
| Average Value | 14 | 5 |
| 80th percentile | 20 | 5 |
| 90th percentile | 27 | 7 |
| 95th percentile | 36 | 9 |
| 99th percentile | 79 | 22 |
It is evident from the above table, that the order of magnitude of anomalous Au values vary greatly between the Luhwaika and Igunda prospect areas, thus highlighting the need, at this stage, to treat each data set separately.
Luhwaika Soil Data
Spatial Distribution Analysis
A Spatial Distribution Analysis of the 504 Luhwaika gold in soil results highlight the following trends:
- Dominant NS trend.
- Dominant 340o trend. The Kigosi Lineament direction.
- Sub-dominant 322o trend.
- Broad N-S trend. A possible regional gold corridor or influencing structure.
Igunda Soil Data
Spatial Distribution Analysis
A Spatial Distribution Analysis of the 504 Luhwaika gold in soil results highlight the following Au trends:
- Strong 322o trend. This appears to be the dominant trend for higher-grade soil samples.
- Sub-dominant N-S trend. A poorly developed regional gold corridor or influencing structure.
- Sub-dominant 304o trend. The Kigosi shear direction.
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The following conclusions can be reached on the geochemical analysis:
- Both the Luhwaika and Igunda soil geochemistry data show a common element in the form of a strong structural/mineralized NS trend. This trend is an important mineralized trend in the Lake Victoria Goldfields and cannot be ignored. This trend is clearly visible on the colour image of the Luhwaika gold in soils and is supported by the IP discussed in the next section.
- Structural data measured on the Luhwaika and Igunda workings are consistent with a significant trend of 322o, parallel to the granite greenstone contact. On the soil geochemistry rose plots, this trend is dominant at Igunda and less obvious at Luhwaika.
- Lesser trends were also found to exist, notably a 304º trend that is parallel to the main Kigosi shear system.
Geophysics:
Geodass SA flew an aeromagnetic and radiometric survey in 1999 for Tanzam 2000 on a 500 m NS line spacing. This forms part of a larger survey which is at present not for public domain. A more detailed magnetic survey was flown by AngloGold-Ashanti in 2004 where they covered some 8600 line km on a 50m line spacing covering the majority of the Project Area.
For drill planning purposes IP is being conducted on 400m spaced lines across Luhwaika, Igunda and Luhwaika -- Igunda gap areas by the Company's in-house geophysical department. A time domain Induced Polarization system was used with an Iris VIP 4000 transmitter (4 kVa), capable of generating a maximum 5 amp current, and an Iris Elrec 6 receiver. Both the transmitter and receiver were operated by Tanzanian technicians. The survey type used was dipole dipole, with a 50 m dipole spacing. Stainless steel electrodes were used. Semi-porous pots with CuSO4 were used at receiver stations, with the following time slices: 240 ms delay, + 160 ms, + 160 ms, + 160 ms, + 160 ms, + 160 ms, + 160 ms, + 160 ms, + 160 ms, + 160 ms, +160 ms. The Tanzanian Royalty in-house geophysicist was in charge of the survey, assisted by two Tanzanian technicians. The position of the lines can be seen on the Geology Map of Luhwaika and Igunda in the Local Geology section. To date five lines have been completed and cover the following areas:
- Two lines over the main Luhwaika showings.
- One line over the NW extension of the Luhwaika workings where soils are still anomalous.
- One line over the main Igunda workings.
- One line over the Luhwaika -- Igunda gap.
The IP line over the Igunda workings has detected two chargeable zones that would surface at +50 (the area where the workings are) and -400. This line will be extended towards the southeast to include the granite greenstone contact area.
IP CHARGEABILITY SECTION 1500S.
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The line conducted over the Luhwaika -- Igunda Gap is discouraging, and it appears that the Igunda and Luhwaika showings do not form one continuous gold system across "the gap". This line also needs to be extended towards the southeast to include the granite/greenstone contact area
IP CHARGABILITY SECTION 00S.
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The three IP lines conducted across the Luhwaika workings are very encouraging. The lines are spaced 800m apart and the position of the lines can be seen on the Geology Map of Luhwaika and Igunda in the Local Geology section.
IP CHARGABILITY SECTION 2450S.
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At Luhwaika five weak NS IP chargeability zones can be traced with some confidence. NE trending Bukoban dykes appear to have affected these zones particularly in the south. The zones vary between 10 and 300m in width. The two eastern zones fall directly on the artisanal workings, and the two western zones coincide with regional magnetic structures. Further IP is planned in early 2007 to map out the extensions to these zones
Drilling:
Drilling commenced at Luhwaika in December 2006.
Future Plans:
An intensive exploration program has been planned and is currently in progress. This program includes:
- Completion of the IP lines to include 400m spaced lines from the Igunda workings to the NW extensions of Luhwaika where soils still suggest potential for gold mineralization. This will total 15 lines along a strike length of 6km. Infill lines will be conducted if required. This work will start again early in 2007.
- A 5000 m RC program where collar and toe fences will be drilled across the main Kigosi structure starting in the vicinity of the workings. RC lines are being planned in conjunction with the IP results. This drill program commenced on 27th November 2006.
Bungoni Prospect Area.
Local Geology:
No detailed geological map exists for the Bungoni Prospect Area. The Prospect is located where the north bounding Kigosi Shear and the Kigosi Lineament intersect (refer to Regional Map). Just north of this junction the airborne magnetics infer that there is a sliver of greenstone sandwiched between the Kigosi Lineament and a sub parallel dyke.
Geochemical Sampling:
AngloGold-Ashanti took some 433 samples within the Prospect Area on a 600m x 100m grid. These samples were submitted to Humac Labs in Mwanza for analysis in October 2006 and results have been received. The 95 percentile is 4ppb and the 99 percentile is 10 ppb. The highest value is 18 ppb.
Spatial Distribution Analysis
A spatial distribution analysis of the gold in soil data suggests a prominent 020º trend. This is supported by contour maps that indicate a 020º trend to the mineralization that extends across 2 lines.
Geophysics:
High resolution aeromagnetics has been conducted over this area by AngloGold-Ashanti.
Drilling:
No drilling has been conducted on this Prospect.
Future Plans:
Infill soil sampling will be conducted in 2007 to see if there is continuity to the anomaly.
Luhwaika East Prospect Area.
Local Geology:
The Luhwaika East Prospect is located on the eastern border of PL3178/05. No geological map exists for this region as there are no outcrops. The high resolution magnetics suggests that there is a folded sliver of greenstones in this area, with the western limb having a NS component. This has been interpreted as being part of the Miyabi - Kigosi greenstone belt.
Geochemical Sampling:
AngloGold-Ashanti took some 364 samples within the Prospect Area on a 600m x 100m grid. These samples were submitted to Humac Labs in Mwanza for analysis in October 2006 and results have been received. The 95 percentile is 6ppb and the 99 percentile is 12.5ppb. The highest value is 21ppb.
Spatial Distribution Analysis
A spatial distribution analysis of the gold in soil data suggests a strong NS trend for the Au in soil geochemistry that coincides with the magnetics. Contour plots of the geochemistry indicate six one point anomalies, with the best anomaly of 21ppb being the first station sampled on one line.
Geophysics:
High resolution aeromagnetics has been conducted over this area by AngloGold-Ashanti.
Drilling:
No drilling has been conducted on this Prospect.
Future Plans:
Infill soils will be conducted in 2007 with lines also being extended to the southwest.
Msonga Prospect Area.
Local Geology:
The Msonga Prospect is located within the Ushirombo Greenstone Belt. The belt consists predominantly of mafic volcanic and intrusive rocks trending EW. A prominent NE trending Bukoban dyke crosscuts the Prospect Area.
Geochemical Sampling:
AngloGold-Ashanti conducted soil sampling on a 200 m x 40 m grid taking some 2060 soil samples. Samples were sent to ALS Chemix, Western Australia for ICP multi element analysis and all results have been returned. The 80 percentile is 9.44 ppb, the 90 percentile is 13.2 ppb, the 95 percentile is 17.2 ppb and the 99 percentile is 34.6 ppb. The highest value is 152 ppb.
Spatial Distribution Analysis
A spatial distribution analysis of the gold in soil data supports a strong EW (105º) trend to the Au in soil geochemistry that coincides with the magnetics. Contour plots of the geochemistry indicate that there are two main zones of mineralization that occur along a subtle 6 km long EW trending zone of gold mineralization. The best anomaly occurs on PL1853/01. This trend is supported by Cu so this represents a Cu/Au system.
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Geophysics:
High resolution aeromagnetics has been conducted over this area by AngloGold-Ashanti.
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