Migori Project Regional Exploration Update

RNS Number : 8015M

Red Rock Resources plc

20 September 2012

 

Red Rock Resources plc

Migori Project Regional Exploration Update - New Prospects Defined

20 September 2012

Red Rock Resources Plc ("Red Rock" or the "Company"), an exploration and mining company with a producing gold mine in Colombia, advanced gold exploration in Kenya, and iron ore interests in Greenland, reports a progress update of the regional exploration of the Migori licences.

Highlights

In the Migori Project, Red Rock is exploring for gold and base metals in an Archaean greenstone belt parallel to the Tanzanian border. The licences are located in SW Kenya. The Mid Migori property covers an area of approximately 300 sq km and is located 20-30 km north of the operating North Mara gold mine in Tanzania.

Three high priority prospects were defined from eight new discoveries in the previously reported reconnaissance shallow aircore drilling programme (announcement of 11 April 2012) and further assessment of the geological context has been carried out. These prospects are in areas away from previously-known mineralisation, as shown in Fig 1. 

Figure 1: Map of Migori Greenstone Belt and the new high priority prospects

http://www.rns-pdf.londonstockexchange.com/rns/8015M_-2012-9-20.pdf

The new high priority prospects, which are generally consistent with known Archaean greenstone gold mineralisation styles, can be summarised as follows:

·     Nyatworo - 1.75km long shear and vein system with two >1.0g/t Au 1m aircore drilling intersections 1km apart, with some associated sulphide alteration of the host rock;

·     Kikongo - 300m x 900m transgressive zone of potential secondary silicification with a 1m @ 1.8g/t Au aircore intersection, 1m @ 1.0g/t in the underlying andesite, and others associated with it, also anomalous silver & base metals; and

·     Masaba - 1m @ 1.6g/t Au in aircore of sericitised andesite along a cross-cutting fault that has 2km historical soil anomalism associated with it.

These results are all in the shallow, weathering-affected profile and may be affected by remobilisation, but are considered very encouraging in these geological contexts. Exploration will focus on these high priority targets and regional geological trends better to understand the anomalous gold concentrations to generate drill targets, but also to continue on the regional datasets and develop new prospects.

Detailed Discussion

Analysis and interpretation of the geological context of the previously-reported regional aircore results have been continuing.  Statistical analysis of the aircore assay results has been completed. Compilation maps with geology and interpreted structure area, analysis of the historical soil sampling data from the 1990s and early-2000s and the aircore drilling results. In addition, the suitability of the aircore and historical soil sampling techniques has been assessed for future work.  The analysis of the data has identified a total of eight new prospects; five in the Nyatworo region and three in the eastern licence area.

The main deposit style expected in the region is greenstone-hosted gold where mineralisation is controlled by shears, veins and faults. In the SPL202 licence area much of the anomalism is also appears to be associated with more pervasive alteration and the presence of nearby late-stage igneous intrusions. It is believed that the igneous intrusions have influenced the geological structure during emplacement and are likely to have influenced the flow of mineralising hydrothermal fluids.

The Nyatworo BIF prospect is slightly different and the target is BIF-hosted mineralisation, which is commonly associated with the hinges of folds and intersections with shear zones and faults. The shears and faults act as a pathway for mineralised fluid while the folds act as a trap for the gold to be deposited.

At Kikongo Prospect there appears to be a combination of both Archaean processes and an overprint of later processes such as local erosion and re-sedimentation, and potentially supergene enrichment.

Western Licence

Nyatworo & Nyatworo South

The Nyatworo Prospect lies along the strike of a significant quartz vein and shear system that dips approximately 60^o to the SW. The veins strike WNW-ESE along the boundary between andesite and quartz porphyry and are the focus of intense artisanal activity. Anomalism has been defined over 1.5km along the vein, and up to 250m width.

The Nyatworo South Prospect lies parallel to the vein, but the anomalism seen in the aircore drilling is more than 100m away from the vein itself, suggesting the possibility of a secondary mineralised feature. It is significant that the anomalism extends a significant distance away from the easily traceable quartz vein, perhaps suggesting that significant fluid flow and alteration of the surrounding rocks has occurred.

Statistical analysis of the results from these prospects indicates that any sample greater than 0.25g/t may be identified as being significantly anomalous, and these included >1.0g/t Au in two samples, 1m @ 1.3g/t Au from 2-3m depth of an altered sulphidic quartz porphyry relatively near the vein, and 1m @ 0.98g/t Au from 8-9m depth in meta-andesite to the south of the vein. Geochemical data shows that there is also base metal anomalism along the whole of this WNW-ESE trend, in particular for lead and zinc.

Figure 2: Map of Nyatworo showing five new prospects, their geology and statistically significant Au values

http://www.rns-pdf.londonstockexchange.com/rns/8015M_1-2012-9-20.pdf

Kikongo

The Kikongo Prospect is centred on the southern tip of a 300m x 900m unit of intensely siliceous material, above the andesite, that extends a short distance to the southwest from a regional NW-SE trending fault line. It is possible that this is a surficial feature, with supergene enrichment, but strong air core anomalism is also seen in the underlying andesite nearby.

The whole area of interest is 300m x 750m. The area is due east of the parallel folds from Nyatworo Central. Two aircore samples, 1m @ 1.8g/t Au from 2-3m depth of the siliceous material and 0.96g/t Au from 12-13m depth in the andesite showed significant anomalism. The sample from the andesite also contains 10g/t Ag. The area also has a good response for copper, lead and zinc and contains several artisanal pits. Further work at this prospect will focus on determining the relationship between gold anomalies and silica alteration.

Nyatworo BIF

The Nyatworo BIF Prospect is located on what appears to be a parasitic fold to a regional-scale fold to the south of Nyatworo Prospect. Geological mapping of the area shows banded iron formations (BIFs) along strike where old artisanal workings exist at the fold hinges to the west of the prospect but these unfortunately were not able to be sampled in the original programme due to rig breakdown.  There are two aircore samples from nearby that were greater than 0.05g/t Au (five times the statistically significant grade of 0.01g/t Au for this lithology), with the maximum being 1m @ 0.12g/t Au from 58-59m depth but this supressed anomalism may be related to surficial leaching, and this area is considered to be of potential due to the chemical as well as structural contrast the BIFs are likely to provide relative to the surrounding lithologies, and so might provide a good host for gold mineralisation.

Kuoma

This is a large area of anomalism without any apparent focus, other than the gentle flexure of the strike of the volcano-sedimentary sequence associated with the margin of a dioritic intrusion. The best aircore sample results, 1m at 0.39g/t Au at 2-3m depth from the weathered material and 1m @ 0.55g/t Au from 20-21m depth of fresh material in the volcano-sedimentary sequence.

Mapped BIFs to the west of the anomalous area were not able to be tested in this program due to poor penetration rates by the lightweight aircore rig, but will also be included in any assessment of the area.

Eastern Licence

Masaba

Masaba is 1.1km x 0.5km in size and the only prospect in the eastern licence where there is material from the aircore samples analysed at over 1g/t Au, with 1m @ 1.6g/t Au from 4-5m depth in sericitised andesite.. There are three other aircore samples of greater than 0.05g/t Au, which are significant as over 90% of the results from this area show less than 0.01g/t Au.

These subsurface anomalies appear to lie along a trend mirrored by the historical soil geochemistry data, which coincides with a NW-SE trending fault line, approximately 1km NW of where the historical geochemistry data detected 0.1-0.5g/t Au in soil samples, indicating that mineralisation is present along the fault.

To the NW of the prospect, along the fault, there is an area of BIF and quartz veining with artisanal pits. It is possible the anomalism may extend to these areas, which would almost double the length of the prospect, from 1.1km to 2km. To the west of the prospect is a large granite intrusion which may be affecting the structure, perhaps focusing the flow of hydrothermal fluids carrying mineralisation.

Masaba South

Masaba South is located on the southern margin of the igneous intrusion. There is one aircore sample from this prospect where greater than 0.08g/t Au at 6-7m depth was measured in shale and arsenic was also detected. The area also shows good base metal anomalism, especially for copper.

Figure 3: Map showing geology and statistically significant Au values of the two Masaba prospects

http://www.rns-pdf.londonstockexchange.com/rns/8015M_2-2012-9-20.pdf

Sagero

Analytical results from this prospect included 1m @ 0.1g/t Au in two aircore samples from 3-4m and 6-7m depth of fresh meta-andesite material, and greater than 0.05g/t Au in another two samples. The host rock of this prospect consists of a mixture of sericitised schist, meta-volcanics and shale. Statistically, over 90% of samples from these lithologies show less than 0.01g/t Au. It is close to a major fault that could be a pathway for mineralization. Positive lead anomalism was also detected in aircore samples from this prospect. One hole intersected quartz-carbonate veins which could also be an indicator of mineralization in the area.

Figure 4: Map showing geology and statistically significant Au values of the Sagero prospect

http://www.rns-pdf.londonstockexchange.com/rns/8015M_3-2012-9-20.pdf

Future Work

Across both licence areas the environment is weathered and leached leading to a subtle anomalism. Further understanding is required of the controls on the observed anomalism (including lithological and structural controls) prior to more advanced exploration.

Further mapping is required across all prospects to determine the extent of shearing and the source of the mineralisation. This will be supported by re-processing of the geophysics data to potentially identify important geological structures underground that can not be seen from the surface due to poor exposure.

At Nyatworo Central further mapping will also help to determine the extent of the BIFs in the area. Around the Masaba Prospect there are a number of mafic units, large quartz veins and BIFs that may be controlling or influencing mineralisation. Further mapping and sampling is required to determine the connection between the lithology and anomalism and potentially extend the prospect further to the north-west.

Conclusion

Andrew Bell, Red Rock Chairman, commenting on these results, states "A priority we have is to identify new targets away from the areas of known gold mineralisation where the existing Mineral Resource Estimates have been defined. The aircore programme has been one element of that process, and we are enthusiastic about these outcomes. Some of the promising targets we have identified will now be priorities for exploration".

Enquiries

Andrew Bell	020 7402 4580 or 07766 474849	Red Rock Resources plc	Chairman
Sandra Spencer	020 7402 4580 or 07757 660 798	Red Rock Resources plc	Press Relations
Gerry Beaney / Daniela Amihood	020 7383 5100	Grant Thornton Corporate Finance	Nominated Adviser
Nick Emerson	01483 413500	Simple Investments Ltd	Broker

The information in this announcement that relates to Exploration Results has been reviewed by Mr Richard Evans, BSc(Hons), who is a Member of The Australasian Institute of Mining and Metallurgy. Mr Evans is a consultant to the Company and an employee of its associate Resource Star Limited, has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking, to qualify as a Competent Person as defined in the 2004 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves" and as a "Qualified Person" as defined in the Note for Mining and Oil & Gas Companies, June 2009, of the London Stock Exchange. Mr Evans has reviewed this announcement and consents to the inclusion herein of the matters based on his information in the form and context in which they appear.

Glossary

Aircore drilling:

Aircore drilling is a cost-effective method of obtaining sub-surface samples of relatively soft materials - in the Kenyan greenstone context this is usually the weathering profile, but still may be stopped by hard horizons such as significant quartz veins, or indurated materials such as ironstones.

Aircore uses hardened steel or tungsten blades to bore a hole into unconsolidated ground. The drill and rods are hollow and contain an inner tube which draws the drill cuttings to the surfaceby injection of compressed air via the outside space between the innertube and the drill rod which reduces sample contamination.

Approximately 35 kg/m of sample is recovered and a representative split of this is sent for analysis in the same way as with percussion drilling techniques.

 

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