Red Rock Resources Plc
Further high grade drilling results indicate the potential of stacked zones of mineralisation at Mikei Gold Project, Migori, SW Kenya
10 July 2012
Red Rock Resources Plc ("Red Rock" or the "Company"), the mining and exploration company with an iron ore project in Greenland, a producing gold mine in Colombia and interests in steel feed, uranium and rare earths, is pleased to announce analytical results from the final round of sampling of recent and historic resource drilling for the Mikei Gold Project within the Migori Project in southwest Kenya, prior to finalisation of an updated Mineral Resource Estimate.
Highlights
All analytical results from Red Rock's 111 hole, 13,375m infill drill programme at the Mikei Gold Project have now been received. These reported assays are from Red Rock's 2011 drilling and recent resampling of historical diamond drilling , and are part of the work leading to a reinterpretation of the Project's economic geology. 75 significant intersections were recorded in this round of results, and the highlights are noted in the tables below, and in Fig 1.
FIGURE 1: Mikei Gold Project drill plan with some highlights of the recent assay results.
The results are all from the KKM-West (KW), Gori Maria (GM) and Nyanza (NZ) Prospects within the Mikei Gold Project, generated in preparation of new Mineral Resource Estimates. CSA Global (UK) Ltd are currently working on the Mineral Resource Estimation according to JORC reporting standards.
Prospect |
Hole ID |
From |
Intersection |
|
Intersection (2) |
KW |
KWDD032 |
74m |
5 m @ 6.51 g/t Au |
including |
2 m @ 13.6 g/t Au |
KW |
KWDD043 |
53m |
6 m @ 3.39 g/t Au |
|
|
KW |
KWDD060 |
107m |
3 m @ 5.30 g/t Au |
including |
1 m @ 13.3 g/t Au |
MK |
MKRC112 |
88m |
3 m @ 3.22 g/t Au |
including |
1 m @ 8.12 g/t Au |
Sampling of historic drill core for some of the prospects was also carried out for additional potential mineralisation following a reinterpretation of the geology.
Prospect |
Hole ID |
From |
Intersection |
|
Intersection (2) |
GM |
MD28 |
88m |
7 m @ 1.85 g/t Au |
|
|
KW |
MD21 |
53m |
11 m @ 4.54 g/t Au |
including |
1 m @ 9.67 g/t Au |
The results are consistent with earlier results from Red Rock and historic drilling and have been integrated into the resource estimation process. The results will refine the detailed understanding of the distribution of mineralisation within the complex, extended Mikei Gold Project shear and vein system.
Of particular interest are a number of strong results from KKM West in what is interpreted to be a series of newly defined locally high grade mineralised surfaces, lying parallel to and above what was previously identified as the main zone of mineralisation. Stacked ore zones greatly increase the chances of the economic development of the mineralisation by open cut mining.
Work Planned
CSA Global (UK) Ltd are currently modelling the Resource Estimates for the Nyanza, KKM-West, Gori Maria and MK Prospects and will classify and report these according to the JORC reporting code.
Pit shells will be then modelled on the best areas of shallow mineralisation with a view to understanding the economic potential development, and for improving the impact of planned drilling. All of this information, along with ongoing mapping and structural analysis will be integrated into the improving geological interpretation to understand the whole of the ~7km long Mikei Gold Project shear system, and in particular the controls over the formation of high grade shoots.
The understanding of the orientation of, and controls over high grade shoots within the broader, more weakly mineralised shear zone is a key element in our understanding of the Mikei Gold Project.
Detailed Discussion
Drill Program
The Mikei Gold Project, covers a mineralised shear zone in an Archaean greenstone belt parallel to the Tanzanian border. There are five distinct shear and vein-hosted prospects defined at present, KKM, KKM-West, MK, Nyanza and Gori Maria (see Fig. 1), within what is thought to be a single shear system of more than 7km strike length.
Red Rock's Mikei Gold Project infill drill programme commenced in November 2010 and drilling continued throughout 2011. Both diamond core and reverse circulation percussion drilling were undertaken, with up to five rigs on site, completing 111 holes for a total of 13,375m. Historical drilling, by a number of explorers of the combined Mikei Gold Project, totalled of 506 holes for 50,590m.
In addition to the 2011 drilling, significant recent resampling of historical diamond drilling has been completed. Recent results and interpretations suggest that the historic drilling may have occurred through the ore zones being defined by ongoing work on the Project.
The samples were prepared at ALS Mwanza, Tanzania and forwarded to ALS Johannesburg, South Africa and ALS Vancouver, Canada for assaying using the fire assay with ICP (low level) / AAS (ore grade) analytical methods.
A full summary of all 75 newly-received significant intersections are listed in the Appendix.
Red Rock has undertaken extensive data validation, resurveying, reassaying, mapping and interpretation to integrate all of this data to generate a properly defined Resource Estimate, and to provide a solid basis for future exploration.
The aim of Red Rock's infill drill program has been to provide additional high quality data to integrate with the existing information so as to enable a robust geological interpretation to target extensions and high grade material to progress towards early development.
With the imminent completion of the remaining Mineral Resource Estimates on the NZ, KW, GM and MK Prospects within the Mikei Gold Project this phase of validation is almost complete.
Geological Interpretation
The Mikei Gold Project, which in places shows alteration and shearing up to 250m wide, appears to be a typical greenstone sequence of interbedded meta-sediments and meta-volcanics with thin sheets of mafic and felsic intrusions parallel to the contact of the Migori Granite to the south. Shearing, quartz veining and traceable zones of mineralisation appear mostly to be sub-parallel to bedding.
Mineralisation at Mikei extends from surface, where artisanal miners conduct shallow, small scale, high grade mining activities at a number of places along strike, down to the limit of current drill testing (~170m).
The new intersections are consistent with earlier results from Red Rock and historic drilling and have been integrated into interpretations being generated for the resource estimation process, and they will refine the detailed understanding of the distribution of mineralisation within the complex, extended Mikei Gold Project shear and vein system. Much effort is being applied to understanding the high grade shoots apparent within the system both for the resource estimation process, but also for the accurate targeting of future drilling.
Key intersections from the current results have had the following impacts on interpretation in the localised Prospect areas as follows:
KKM-West (KW)
KW prospect is dominated by rocks of the Nyanzian system of the Archean of western Kenya. The dominant lithologies are intermediate volcaniclastics and metasedimentary rocks, quartz porphyry and black shale are common rock types in the prospect. These are bordered by meta-andesites and mafic to intermediate volcanics such as basalts and gabbros which occur in the Nyanza Prospect (to the west).The rocks are generally heavily sheared.
Like most parts of the Migori greenstone belt, the gold mineralisation occurs within these sheared zones. Gold mineralisation is common in stockworks of quartz veins and stringers and shear host rocks, some of the vein lodes are porphyry hosted. Elevated gold grades are mostly associated with zones of alteration and silicification.
The new results at KKM West have helped define a number of strong 'hanging wall' mineralised zones that lie above what had previously been defined as the main mineralised surface. Logging and analysis of recent drilling recognised a coherent hanging wall surface (Fig 2A), that encouraged the re-assaying of a number of historical diamond holes such as MD21: 11.0m @ 4.54g/t Au from 53m (Fig 2B).
FIGURE 2 A & B: KKM West Cross Sections showing the hanging wall surface defined by recent results
What is interpreted to be another hanging wall pod of mineralisation, closer to the main lower zone of mineralisation, has also been confirmed by KWDD32: 5m @ 6.51g/t Au (Fig 3).
FIGURE 3 A & B: KKM West Cross Section and Long Section showing another pod of high grade hanging wall mineralisation defined by recent results
The occurrence of stacked zones of mineralisation increases the chances of potential development by reducing the stripping ratio in an open pit mining operation, and even constrained pods of higher grade material within them greatly increase the possibility of economic development.
The interpretation of the controls over these high grade zones within the broader, more weakly mineralised shear zone is a key part of the understanding of the Mikei Gold Project.
All prospects along the main east-west trend of the Mikei Shear system appear to be consistent with a number of stacked, variably mineralised zones within a wider shear zone, usually with the northern-most shear or vein being the best mineralised, but the definition of high grade 'hanging wall' shoots within the KKM West system confirms the potential of the whole of the shear zone, and work will continue to understand what localises high grade gold within the system.
Validation of Mikei Gold Project Resource Estimate
Mineral Resource Estimates for the remaining Prospects within the Mikei Gold Project are currently underway with the detailed interpretation of structural, lithological, mineralogical, alteration and assay data to define the ore blocks. The KKM Prospect was reported to contain an Indicated and Inferred JORC Resource of 17.8 Mt @ 1.01g/t Au for 577 kOz Au in December 2011.
The Mineral Resource Estimates from the other prospects within the Mikei Gold Project are expected shortly.
The information in this report that relates to Exploration Results is based on information reviewed by Mr Richard Evans, who is a Member of The Australasian Institute of Mining and Metallurgy. Mr Evans is an employee of the Red Rock Group of Companies and 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 the information in this announcement and consents to the inclusion of the information in the form and context in which it appears.
Enquiries:
Andrew Bell |
020 7402 4580 or |
Red Rock Resources plc |
Chairman |
Sandra Spencer |
020 7402 4580 or |
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 |
Appendix 1 - Significant Intersections Mikei Gold Project
Prospect |
Company |
Hole ID |
mE |
mN |
EOH (m) |
No. Mineralised Zones |
From depth (m) |
Intersection Width (m) |
Grade |
Gori Maria |
RRR |
GMRC006 |
646934.631 |
9888250.042 |
150 |
1 |
128 |
3.0 |
1.30 |
KKM-West |
RRR |
KWDD031 |
643488.607 |
9889781.153 |
101.56 |
1 |
65 |
2.0 |
0.98 |
KKM-West |
RRR |
KWDD032 |
643420.161 |
9889761.009 |
167.76 |
4 |
64 |
6.0 |
0.90 |
|
|
|
|
|
|
|
74 |
5.0 |
6.51 |
|
|
|
|
|
|
including |
77 |
2.0 |
13.6 |
|
|
|
|
|
|
|
133 |
1.9 |
0.53 |
|
|
|
|
|
|
|
140 |
1.3 |
0.73 |
KKM-West |
RRR |
KWDD035 |
643472.619 |
9889745.940 |
149.66 |
2 |
107 |
5.0 |
0.52 |
|
|
|
|
|
|
|
139 |
2.0 |
2.33 |
KKM-West |
RRR |
KWDD036 |
643466.948 |
9889710.897 |
197.86 |
1 |
117 |
0.7 |
0.79 |
KKM-West |
RRR |
KWDD037 |
643443.395 |
9889675.824 |
164.86 |
1 |
160 |
1.0 |
0.97 |
KKM-West |
RRR |
KWDD039 |
642962.467 |
9890054.240 |
101.58 |
1 |
20 |
1.0 |
1.16 |
KKM-West |
RRR |
KWDD043 |
642974.296 |
9890091.129 |
110.38 |
2 |
26 |
1.0 |
0.98 |
|
|
|
|
|
|
|
53 |
6.0 |
3.39 |
KKM-West |
RRR |
KWDD051 |
643049.728 |
9890012.348 |
101.38 |
3 |
8.3 |
1.4 |
0.96 |
|
|
|
|
|
|
|
14 |
1.0 |
1.30 |
|
|
|
|
|
|
|
57 |
11.0 |
1.12 |
KKM-West |
RRR |
KWDD060 |
643382.781 |
9889783.623 |
170.86 |
4 |
67 |
6.5 |
1.24 |
|
|
|
|
|
|
|
107 |
3.0 |
5.30 |
|
|
|
|
|
|
including |
108 |
1.0 |
13.3 |
|
|
|
|
|
|
|
115 |
1.3 |
3.02 |
|
|
|
|
|
|
|
133 |
4.0 |
2.93 |
KKM-West |
RRR |
KWDD061 |
643087.399 |
9889859.860 |
179.38 |
3 |
139 |
2.0 |
1.20 |
|
|
|
|
|
|
|
146 |
1.0 |
1.45 |
|
|
|
|
|
|
|
157 |
2.0 |
0.91 |
KKM-West |
RRR |
KWDD062 |
643390.933 |
9889673.784 |
194.86 |
1 |
194 |
0.9 |
4.49 |
KKM-West |
RRR |
KWDD065 |
643106.249 |
9889898.976 |
146.38 |
2 |
114 |
1.0 |
1.68 |
|
|
|
|
|
|
|
118 |
1.0 |
1.13 |
KKM-West |
RRR |
KWDD070 |
643156.426 |
9889764.351 |
200.48 |
2 |
131.4 |
2.3 |
2.52 |
|
|
|
|
|
|
|
136.4 |
1.0 |
1.09 |
KKM-West |
RRR |
KWDD073 |
643168.623 |
9889790.826 |
200.68 |
3 |
47 |
1.0 |
1.78 |
|
|
|
|
|
|
|
92 |
4.0 |
0.89 |
|
|
|
|
|
|
|
177 |
10.9 |
1.05 |
KKM-West |
RRR |
KWDD078 |
643190.690 |
9889833.223 |
188.38 |
6 |
41 |
1.0 |
1.23 |
|
|
|
|
|
|
|
44.2 |
6.8 |
1.57 |
|
|
|
|
|
|
|
66 |
1.0 |
2.82 |
|
|
|
|
|
|
|
125.6 |
2.5 |
2.27 |
|
|
|
|
|
|
|
132 |
0.69 |
1.20 |
|
|
|
|
|
|
|
150 |
3.98 |
1.20 |
KKM-West |
RRR |
KWDD083 |
643202.338 |
9889867.812 |
152.38 |
5 |
19 |
1.0 |
1.02 |
|
|
|
|
|
|
|
56 |
2.0 |
1.34 |
|
|
|
|
|
|
|
89 |
2.0 |
1.68 |
|
|
|
|
|
|
|
100 |
5.0 |
1.17 |
|
|
|
|
|
|
|
108 |
1.0 |
0.94 |
KKM-West |
RRR |
KWDD085 |
643247.369 |
9889841.086 |
152.38 |
6 |
36 |
1.0 |
1.49 |
|
|
|
|
|
|
|
84 |
5.0 |
1.19 |
|
|
|
|
|
|
|
91 |
1.0 |
1.16 |
|
|
|
|
|
|
|
100.86 |
1.0 |
0.94 |
|
|
|
|
|
|
|
103.86 |
1.0 |
1.45 |
|
|
|
|
|
|
|
114 |
4.0 |
1.40 |
KKM-West |
RRR |
KWDD087 |
643287.941 |
9889809.369 |
165.38 |
4 |
88 |
4.0 |
0.89 |
|
|
|
|
|
|
|
102 |
1.0 |
0.95 |
|
|
|
|
|
|
|
104.3 |
2.5 |
1.11 |
|
|
|
|
|
|
|
133 |
4.0 |
1.83 |
MK |
RRR |
MKDD057 |
644829.236 |
9889562.753 |
137.86 |
1 |
136 |
1.0 |
1.38 |
MK |
RRR |
MKDD059 |
644786.273 |
9889706.657 |
152.48 |
1 |
99 |
0.5 |
1.98 |
MK |
RRR |
MKDD110 |
644444.734 |
9889814.607 |
158.86 |
2 |
86.5 |
5.0 |
1.47 |
|
|
|
|
|
|
|
153.5 |
1.0 |
1.02 |
MK |
RRR |
MKDD111 |
644403.651 |
9889805.455 |
134.76 |
2 |
67.2 |
1.29 |
1.70 |
|
|
|
|
|
|
|
116 |
3.48 |
1.08 |
MK |
RRR |
MKRC112 |
644321.867 |
9889869.930 |
102 |
1 |
88 |
3.0 |
3.22 |
|
|
|
|
|
|
including |
90 |
1.0 |
8.12 |
|
|
|
|
|
|
|
|
|
|
Prospect |
Company |
Hole ID |
mE |
mN |
EOH (m) |
No. Mineralised Zones |
From depth (m) |
Intersection Width (m) |
Grade |
MK |
Historic - SBK |
MK006 |
644552.736 |
9889762.035 |
113.55 |
1 |
17 |
2.7 |
1.10 |
MK |
Historic - SBK |
MK031 |
644693.877 |
9889710.647 |
140.04 |
1 |
62 |
1.0 |
1.44 |
MK |
Historic - KAN |
MK046 |
644531.485 |
9889631.059 |
250.23 |
1 |
223 |
1.0 |
0.99 |
Nyanza |
Historic - KAN |
MD11 |
640874.048 |
9890893.045 |
223 |
1 |
118 |
2.0 |
2.59 |
Nyanza |
Historic - KAN |
MD22 |
640846.775 |
9890978.108 |
198 |
1 |
55 |
1.0 |
1.16 |
Gori Maria |
Historic - KAN |
MD14 |
647234.885 |
9888263.926 |
142 |
1 |
69 |
1.0 |
1.41 |
Gori Maria |
Historic - KAN |
MD27 |
647024.754 |
9888213.443 |
151.38 |
3 |
96 |
1.0 |
1.33 |
|
|
|
|
|
|
|
121 |
5.0 |
1.01 |
|
|
|
|
|
|
|
151 |
0.38 |
2.62 |
Gori Maria |
Historic - KAN |
MD9 |
647166.645 |
9888181.625 |
226 |
1 |
22 |
2.0 |
1.78 |
Gori Maria |
Historic - KAN |
MD28 |
647162.623 |
9888262.833 |
181.38 |
2 |
18.5 |
1.5 |
3.11 |
|
|
|
|
|
|
|
88 |
7.0 |
1.85 |
KKM |
Historic - KAN |
MD1 |
645033.187 |
9888892.913 |
202 |
2 |
111 |
2.0 |
2.75 |
|
|
|
|
|
|
|
185 |
3.0 |
1.61 |
KKM-West |
Historic - KAN |
MD20 |
643244.274 |
9889777.535 |
241.5 |
1 |
95 |
3.0 |
1.15 |
KKM-West |
Historic - KAN |
MD21 |
643195.540 |
9889800.759 |
199.55 |
1 |
53 |
11.0 |
4.54 |
|
|
|
|
|
|
including |
63 |
1.0 |
9.67 |
Notes:
1. "Significant intersections" are based on composites in excess of 0.5g/t Au, including up to 2m of internal waste, where the intersection is greater than the equivalent of 1m @ 1g/t Au.
2. All drill holes were drilled on an azimuth of 025 degrees, and a dip of -60 degrees.
3. Coordinates are SUTM ARC1960
4. Sample preparation at ALS Mwanza, Tanzania and forwarded to ALS Johannesburg, South Africa and ALS Vancouver, Canada for assaying using the fire assay with ICP (low level) / AAS (ore grade) analytical methods
5. All intersections down-hole widths