Sierra Mining Limited announces further outstanding drill results at Mabilo



PERTH, Western Australia, May 13, 2014 /CNW/ - RTG Mining Inc. and its subsidiaries ("RTG" or "the Company") are pleased to announce that Sierra Mining Limited ("Sierra") has released an announcement of further outstanding results from its on-going drilling program at the Mabilo Project in the Philippines. The announcement is attached to this release and can be found on their website at and will also be available on  under RTG's platform.

About RTG
RTG Mining Inc. is a British Virgin Islands-incorporated company listed on the main board of the TSX.  It is a mining exploration company focused on identifying new gold development and operating acquisition opportunities.

RTG has sold its interest in the Mkushi Copper Project in Zambia for consideration of US$13.1m, including US$6.6m in shares of Elephant Copper Limited and a convertible note due in January 2015 for US$6.5m.  RTG has also entered into a sale agreement for its interest in the Segilola Gold Project in Nigeria to the current joint venture partner for a total consideration of US$14m, with US$1m due on completion, US$5m due in 18 months after completion and a 3% net smelter royalty, under which up to a maximum of US$8m may be paid to RTG. The sale also resolves the existing dispute with the current joint venture partner.  Completion is anticipated in the next couple of months.  RTG is currently undertaking a merger with Sierra Mining Limited ("Sierra"), an Australian Securities Exchange listed exploration company, holding several key advanced copper/gold projects in the Philippines. The merger is expected to complete in early June 2014, and the resultant entity will be led by the RTG management team who have the proven exploration, mine development and operating experience in the Philippines to progress Sierra's Mabilo and Bunawan Projects.

RTG is led by the previous management team of CGA Mining Limited which developed the Masbate Gold project in the Philippines and successfully merged with B2Gold Corp. in a US$1.1bn scheme of arrangement in January 2013.  The RTG Board comprises Michael Carrick (Chairman), Justine Magee (President and CEO), Phil Lockyer, David Cruse and Rob Scott (Non Executive Directors).

Cautionary Note Regarding Forward Looking Statements

Certain statements contained in this announcement constitute forward looking statements within the meaning of applicable securities laws including, among others, statements made or implied relating to the Company's objectives, strategies to achieve those objectives, the Company's beliefs, plans, estimates and intentions, and similar statements concerning anticipated future events, results, circumstances, performance or expectations that are not historical facts.  Forward looking statements generally can be identified by words such as "objective", "may", "will", "expect", "likely", "intend", "estimate", "anticipate", "believe", "should", "plans" or similar expressions suggesting future outcomes or events.  Such forward looking statements are not guarantees of future performance and reflect the Company's current beliefs based on information currently available to management.  Such statements involve estimates and assumptions that are subject to a number of known and unknown risks, uncertainties and other factors inherent in the business of the Company and the risk factors discussed in the Annual Information Form and other materials filed with the securities regulatory authorities from time to time which may cause the actual results, performance or achievements of the Company to be materially different from any future results, performance or achievements expressed or implied by such forward looking statements.  Those risks and uncertainties include, but are not limited to: the mining industry (including operational risks; risks in exploration, and development; the uncertainties involved in the discovery and delineation of mineral deposits, resources or reserves; and the uncertainty of mineral resource and mineral reserve estimates); the risk of gold, copper and other commodity price and foreign exchange rate fluctuations; the ability of the Company to fund the capital and operating expenses necessary to achieve the business objectives of the Company; the uncertainty associated with commercial negotiations and negotiating with foreign governments; the risks associated with international business activities; risks related to operating in Nigeria and the Philippines; environmental risk; the dependence on key personnel; and the ability to access capital markets.

Readers are cautioned not to place undue reliance on these forward looking statements, which speak only as of the date the statements were made and readers are advised to consider such forward looking statements in light of the risks set forth above.  Except as required by applicable securities laws, the Company assumes no obligation to update or revise any forward looking statements to reflect new information or the occurrence of future events or circumstances.


The technical information in this news release has been reviewed by and approved by Mark Turner for Ratel Group, and a Qualified Person under National Instrument 43-101 - Standards of Disclosure for Mineral Projects.

Mr. Alfred John Gillman of Odessa Resources Pty Ltd, an independent qualified person experienced in the style of mineralisation at the Segilola Gold Project, has completed the resource statement for the Segilola Project as referred to in this announcement, including verification of the sampling, analytical and test data underlying the estimate. Verification also included a site visit, database validation of historical drill results and a review of sampling and assaying protocols.  The qualified person was satisfied with all of the protocols used during the drilling, sampling and in the Segilola resource estimate compilation and computation.

With regard to the Mkushi Copper Project, Matthew Nimmo of Snowdens is the qualified person and has verified the resource statement as disclosed in this announcement, including sampling, analytical and test data underlying the estimate. Verification of the data included numerous site visits, database validation of historical drill results and review of sampling and assaying protocols.  The qualified person was satisfied with the verification process.

The technical information in this news release has been reviewed by and approved by Mark Turner for Ratel Group, and a Qualified Person under National Instrument 43-101 - Standards of Disclosure for Mineral Projects.



Sierra Mining Limited ("Sierra" or "the Company") is pleased to present further outstanding results from its on-going drilling program at the Mabilo Project in the Philippines.

Highlights from the ongoing diamond drilling program include drill holes extending both the down dip and SE strike extension of the South Body and drill holes extending the known mineralisation along strike to both the north and south of the North Body magnetic model.

  • Holes MDH-53 and MDH-57, respectively drilled 50 and 100 metres to the SE of MDH-40, have intersected substantial widths of magnetite-chalcopyrite mineralisation, thereby extending the known strike of the large South Body over 100m. Drilling is continuing at MDH-57 and neither hole has been assayed as yet however, mineralisation is visually similar to holes MDH-16 and MDH-40.

  • Hole MDH-46 confirmed the down dip extension of the South Body to the SE, intersecting two zones of magnetite-chalcopyrite mineralisation:

    40.45m at  1.81 g/t Au,  1.38 % Cu,  25.0 g/t Ag and  41.26 % Fe, and

    4.20m at  2.13 g/t Au,  1.96 % Cu,  16.5 g/t Ag and  50.55 % Fe.
  • Hole MDH-48 intersected magnetite skarn and mineralised silica pyrite breccia extending the known magnetite skarn mineralisation 50m south of the southern boundary of the North Body. The hole intersected:

    166.2m at  1.29 g/t Au,  1.27 % Cu,  8.3 g/t Ag and  32.46 % Fe.
  • MDH-41 drilled sub-parallel and approximately 40 metres north of the north boundary of the modelled North Body intersected:

    54.8m at  1.01 g/t Au,  2.40 % Cu,  14.3 g/t Ag and  19.99 % Fe.

Further details are set out below.

Enquiries:     Matt Syme, Managing Director, +61 8 9322 6322  or +61 417 906 717



The Mabilo Project is located in Camarines Norte Province, Eastern Luzon, Philippines. It comprises one granted Exploration Permit (EP-014-2013-V) of approximately 498 ha and Exploration Permit Application EXPA-000188-V of 2,820 ha. The Project area is relatively flat and is easily accessed by 15 km of all-weather road from the highway at the nearby town of Labo.

Sierra is exploring three zones of blind massive magnetite skarn containing copper, gold and silver mineralisation termed the North, South and East bodies as shown in Figure 1 below. A fourth magnetic anomaly at Venida South lies along strike from a former small-scale mining operation but has yet to be drill tested. Three initial scout holes at the NE Anomaly returned inconclusive results.

Drilling is currently focused on defining the SE strike and SW down dip extent of the large South Body and testing the strike extension of mineralisation to the north and south of the North Body.

There are currently three drilling rigs on site and 55 holes have been completed to date. Assay and drilling results subsequent to the March 2014 Quarterly Report are summarised below.

South Body

Drilling has concentrated on the South Body which is substantially larger than the North and East Bodies. Modeling of the ground magnetics in conjunction with the magnetic susceptibility readings from drill core indicates a large tabular shaped body which strikes to the NW (plunging shallowly to the SE) and dips variably to the SW at approximately 45 degrees (Figure 2).

The modelled body is approximately 340 metres long and drilling has now intersected Cu-Au-Ag enriched magnetite skarn mineralisation along the entire strike length. The mineralisation pinches out along its upper NE edge but is open down dip to the SW along most of its length. The SW down dip extension is unconstrained by magnetic modeling as it dips below the depth reliably modelled from the ground magnetic data and has not been closed off by drilling to date.

Hole MDH-57 also indicates the mineralisation extends beyond the SE limit of the magnetic model.


An angled hole drilled to test the NE edge of mineralisation passed over the edge of the body and failed to intersect magnetite mineralisation. A zone of relatively Fe rich garnet skarn overlying hornfelsed sediments enriched in remobilised Au and Cu indicates the hole intersected the halo of the magnetite mineralisation.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
94 104.5 10.5 0.02 0.01 bdl 19.05 Retrograde altered garnet skarn
104.5 124 19.5 0.30 0.41 1.7 4.10 Hornfels sediment


An angled hole drilled from the same collar as MDH-40 aimed at testing the up dip extension of the mineralisation to the NE of MDH-40. The hole intersected oxidized magnetite skarn significantly depleted in Cu. The Cu and Au appear to have been remobilised into the surrounding rocks. The hole is similar in thickness and grade to MDH-04 along strike to the NW which is also underlain by a breccia / fault zone.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
99 101.1 2.1 0.13 0.19 bdl 11.56 Hornfels sediment
101.1 118.55 17.45 0.38 0.08 bdl 48.46 Magnetite-hematite skarn
118.55 127 8.45 0.69 0.47 1.8 3.10 Breccia / Fault zone
99 127 28 0.45 0.20 na 32.00 Total Intersection


A vertical hole drilled to test the down dip extent of the high grade mineralisation intersected in MDH-16 and MDH-40. The hole intersected un-mineralised marble from 174.4-237.3 m, from 277.75-284.25 and from 288.2 to the EOH at 325 m. Mineralised magnetite skarn was intersected in two intervals between the marble as shown in the table below.

From To Metres Au g/t Cu% Ag g/t Fe % Lithology
174.4 237.3 62.9         Marble
237.3 277.75 40.45 1.81 1.38 25.0 41.26 Magnetite skarn
277.75 284.25 6.5         Marble
284.25 288.45 4.2 2.13 1.96 16.5 50.55 Magnetite skarn

The marble which had not been intersected in any hole in the South Body previously is a poor host for the magnetite mineralisation which preferentially replaces the garnet skarn (formed from marls and limey sediments) surrounding the marble. The extent of the marble body is unknown at this stage and it is possible the magnetite mineralisation in this area is more steeply dipping than interpreted from extrapolating intersections in hole MDH 04, 16, 40 and 44 and thus the intersections in the table above may be drilled down the dip of the mineralisation.


An angled hole to test the down dip extent of the mineralisation in holes MDH-18 and 19. The hole was abandoned at 166 metres due to drilling difficulties on the interpreted edge of the mineralisation. The hole is being re-drilled (as MDH-56). The hole supports the interpretation that the mineralisation is more steeply dipping in this area than the extrapolation from holes MDH-18 and 19 indicates.


A vertical hole drilled to test the strike continuation of the high grade mineralisation in MDH-40 and 16. The hole intersected magnetite-chalcopyrite mineralisation from 108 to 182.8 metres, visually consistent with the results from MDH-40 and MDH-16. Significantly the hole also intersected an extensive zone of mixed magnetite-garnet skarn from 187.8m to 221.1m overlying a zone of garnet skarn/hornfelsed sediments containing chalcopyrite along fractures to the EOH at 243.9m. These zones underlying the main zone of magnetite-chalcopyrite were not intersected in adjacent holes.

Assay results have not been received for this hole.


An angled hole drilled from the same collar as MDH-53 to test the up dip continuity of the mineralisation in MDH-53. The hole intersected a zone of mixed magnetite-chalcopyrite, pyrite and garnet skarn over 30.75 metres consistent with the intersection in MDH-44 along strike to the NW.

Assay results have not been received for this hole.


An angled hole, currently being drilled to replicate abandoned hole MDH-51, to test the down dip extent of the mineralisation in holes MDH-18 and 19. The hole has not yet reached target depth.

MDH- 57

A vertical hole to further test the strike extent of mineralisation in hole MDH-53. The hole encountered magnetite skarn from 128 metres to the current depth of 154 m (as at 7.00 AM Monday 12 May). The magnetite contains chalcopyrite at visually estimated levels similar to holes MDH-53 and MDH-40 along strike to the NW.

North Body

Drilling on the North Body has concentrated on exploring the north and south strike extensions of the modelled magnetite body. The mineralisation appears to be localized along the margin of the diorite intrusion and plunges shallowly to both the north and south of the modelled body which appears to reflect a zone where the mineralisation is both wider and closer to the surface. The mineralisation appears to dips shallowly to the west, thinning against the diorite along the eastern margin but is still open along the western margin as well as to the north and south.

The diorite margin is marked by a zone of intense fracturing, intercalation of sediments, diorite, garnet skarn and magnetite alteration overprinted by widespread retrograde argillic alteration.


An angled hole aimed at testing the southern strike extent of the North Body mineralisation. The hole intersected andesite, hornfelsed sediment and minor garnet skarn interpreted to represent the contact zone between the sediment host sequence and the diorite body. Variably elevated Cu, Au and Fe values were recorded but no significant mineralisation was intersected.


An angled hole drilled to test the zone of mineralisation intersected in hole MDH-11 to the north of the magnetite body. The hole intersected argillic altered and weathered hornfelsed sediment and retrograde altered garnet skarn with disseminated chalcocite and chalcopyrite.

From To metre Au g/t Cu % Ag g/t Fe % Lithology
56.2 87.5 31.3 1.54 3.94 23.5 17.93 Hornfels sediment and chalcocite
Inc.  71 75 4 1.59 13.85 76.3 23.08 Chalcocite rich zone
87.8 111 23.2 0.30 0.36 2.0 23.04 Hornfels sediment and garnet skarn
56.2 111 54.8 1.01 2.40 14.3 19.99 Total intersection

The hole was drilled sub-parallel to and approximately 40 m north of the modelled magnetite body thus confirming the northern strike extent of the North Body mineralisation.


A steeply angled hole drilled from the same collar as MDH-43 was abandoned on the edge of mineralisation due to drilling difficulties. The hole intersected a supergene enriched zone (disseminated chalcocite) up hole and a bottom of hole intercept grading 1.70% copper on the edge of the interpreted magnetite skarn mineralisation.

From To metres Au g/t Cu % Ag g/t Fe % Lithology
48 51.4 3.4 0.81 2.68 18.5 9.17 Hornfels sediment, chalcocite
76 115.9 39.9 0.07 0.16 1.1 14.33 Garnet skarn and mag/hematite
inc 115.4 115.9 0.5 0.38 1.70 3.5 13.51 Magnetite and garnet skarn


A vertical hole to test the east edge of the North Body and a potential extension of the high grade supergene zone in MDH-20. The hole intersected magnetite skarn with an upper oxidized hematite zone containing a zone of chalcocite enrichment. The magnetite skarn is underlain by andesite and garnet skarn containing widespread chalcopyrite along fractures.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
44.0 61.6 17.6 2.16 6.52 10.1 44.29 Hematite/ Magnetite skarn
Inc 45.8 52.4 6.6 2.05 13.77 16.9 37.30 Chalcocite zone
61.6 84.4 22.8 0.48 0.66 3.8 4.78 Garnet skarn with chalcopyrite
44 84.4 40.4 1.21 3.22 6.6 21.99 Total intersection


An angled hole drilled to the SW from the same collar as MDH-45 to test the southern margin of the modelled magnetite body. The hole intersected magnetite-chalcopyrite mineralisation extending 20m south of the boundary of the modelled body, before passing through the base of the magnetite into a mineralised silica-pyrite matrix breccia.

From To Interval Au g/t Cu % Ag g/t Fe % Lithology
43 147.6 104.6 1.78 1.79 11.9 43.41 Magnetite skarn
147.6 147.8 0.20         No core recovery
147.8 209.2 61.4 0.46 0.38 2.1 13.91 Silica-pyrite breccia
209.2 209.3 0.10         No core recovery
209.3 230.9 21.6 0.11 0.20 1.5 4.44 Garnet skarn with chalcopyrite
43 209.2 166.2 1.29 1.27 8.3 32.46 Combined Intersection

The breccia zone contains clasts of garnet skarn and hornfelsed sediment in addition to clasts of the overlying mineralised magnetite skarn. The breccia has only been intersected within and underlying magnetite mineralisation elsewhere at Mabilo, thus by inference the North Body magnetite minersalisation is interpreted to extend above the breccia a further 30 metres to the SSW, extending the potential magnetite mineralisation a combined 50 metres south of the magnetic model boundary. The base of the magnetite intersected in MDH-48 is deeper than the base of the magnetite intersected within the North Body magnetic model, indicating that the mineralisation is plunging gently to the SSW.

The breccia zone is underlain by retrograde argillic altered garnet skarn and hornfels sediments with chalcopyrite along fracture zones to the end of the hole at 230.9 metres.

A -50 degree angled hole to test the mineralisation immediately north of the North Body magnetic model boundary. The hole appears to have intersected the upper western edge of the magnetite skarn, intersecting hematitic oxidized magnetite and garnet skarn from 71 - 90.05 metres, and a mineralised breccia zone from 138.6 to 151.4 metres.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
71 90.05 19.05 1.07 0.58 1.8 25.93 Hematite/garnet skarn
138.6 151.4 12.8 0.62 0.79 7.0 16.28 Breccia Zone

A -65 degree angled hole drilled from the same collar as MDH-50. The hole intersected a hematite rich zone from 70 to 75 metres and a zone intercalated magnetite/hematite skarn and clay altered garnet skarn from 91 m to 185.2 metres where it passed into marble. Chalcopyrite is abundant in places within the magnetite skarn. No assays have been received.

An angled hole to further test the mineralisation in MDH-52. The hole intersected a hematite zone between 116 and 131.5 metres and massive magnetite-chalcopyrite from 171 - 190 metres where it passed into marble. No assays have been received.

East Body

The east body was discovered by drilling a ground magnetic anomaly. The body was initially modelled as a flat-lying body but the initial three holes (MDH-23, 27 and 37) which all intersected magnetite mineralisation as reported previously indicated the mineralisation dipped to the SW. The model was revised indicating two discrete zones of mineralisation as shown in the figure below. A further three holes reported below were drilled to test the extent of the revised magnetic model.

A vertical hole which intersected extensive silicification and biotite alteration but did not intersect magnetite skarn mineralisation. The hole is interpreted to be adjacent to the edge of the magnetite skarn.

The hole was drilled at a steep angle to the SSE to test the northern block of the revised magnetic model. The hole intersected a cavity in the garnet skarn filled with blocks of garnet skarn and alluvial quartz sand and magnetite sand at the base.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
42.8 52.55 9.75 0.42 0.93 6.7 46.61 Cavity fill
52.55 110.2 57.65 0.17 0.27 3.6 17.93 Garnet skarn with magnetite veins

The garnet skarn underlying the cavity contains veins of magnetite skarn and chalcopyrite along fractures and is interpreted to represent the low grade halo on the edge of the magnetite skarn.

A vertical hole to test the southern end of the modelled body. The hole intersected three narrow zones of oxidized magnetite skarn separated by zones of un-mineralised marble.

From To Metres Au g/t Cu % Ag g/t Fe % Lithology
134.1 137.1 3 0.06 0.27 2.3 53.34 Magnetite skarn
169.1 170.6 1.5 0.08 0.71 4.4 55.56 Magnetite skarn
175 178.45 3.45 0.67 1.55 21.9 49.04 Magnetite skarn *
178.45 186.1 7.65 0.07 0.23 2.3 11.70 Garnet skarn

*Includes 0.30 m interval of no core recovery assigned zero value for all elements

A revised magnetic model of the Eastern Body will be conducted prior to follow up drilling.

Competent Person Statement

The information in this report that relates to the second phase of drilling at the Mabilo Project is based on information compiled by Mr Robert McLean, a Competent Person who is a member of the Australasian Institute of Mining and Metallurgy. Mr McLean is a consultant geologist engaged by Sierra Mining Limited. Mr McLean has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaking, to qualify as a Competent Person as defined in the 2012 Edition of the "Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves". Mr McLean consents to the inclusion in the report of the matters based on his information in the form and the context in which it appear.

The information in this report relating to exploration results, other than the second phase of drilling at the Mabilo Project, is based on information provided to Mr Robert McLean by Sierra Mining Limited. Mr McLean is a consultant geologist and is a member of the Australasian Institute of Mining and Metallurgy. Mr McLean 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'.  Mr McLean consents to the inclusion in the report of the matters based on his information in the form and context in which it appears. This information was prepared and first disclosed under the JORC Code 2004. It has not been updated since to comply with the JORC Code 2012 on the basis that the information has not materially changed since it was last reported.

Appendix 1: Location of Drill holes reported

HOLE BODY Easting Northing Elev. Inclination Azimuth EOH
MDH-38 SOUTH 476,094 1,559,915 118 60 050 132.1
MDH-39 NORTH 476,078 1,560,166 105 60 090 123.6
MDH-41 NORTH 476,066 1,560,331 107 60 090 134.5
MDH-42 EAST 476,780 1,559,815 115 90 - 120.4
MDH-43 NORTH 476,066 1,560,331 107 80 090 115.9
MDH-44 SOUTH 476,170 1,559,788 125 60 050 155.0
MDH-45 NORTH 476,138 1,560,235 105 90 - 131.8
MDH-46 SOUTH 476,114 1,559,785 124 90 - 325.0
MDH-47 EAST 476,857 1,559,870 114 80 160 135.0
MDH-48 NORTH 476,138 1,560,235 105 60 220 230.9
MDH-49 EAST 476,775 1,559,729 115 90 - 213.7
MDH-50 NORTH 476,150 1,560,300 115 50 270 192.4
MDH-51 SOUTH 476,032 1,559,790 110 60 050 166.0
MDH-52 NORTH 476,150 1,560,300 115 65 270 194.1
MDH-53 SOUTH 476,209 1,559,759 125 90 - 243.9
MDH-54 NORTH 476,200 1,560,300 115 60 270 231.8
MDH-55 SOUTH 476,209 1,559,759 125 75 050 180.6
MDH-56 SOUTH 476,032 1,559,790 110 65 050 -
MDH-57 SOUTH 476,241 1,559,720 122 90 - -

All co-ordinates in UTM-WGS84 (51 N). All collars apart from MDH-38 only surveyed by digital GPS at this stage.

Holes MDH-42 and MDH-51 failed to intersect mineralisation and no assay results are reported. Holes MDH-56 and 57 are still in progress. Assay results for completed holes MDH-52 - 55 are not available.

Appendix 2:  Drilling Results included in this report dated 13 May 2014

Section 1 - Sampling Techniques and Data:      MABILO

Criteria Explanation Commentary
Sampling techniques Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. The assay data reported herein is based on sampling of Diamond Drill core of PQ and HQ diameter which was cut with a diamond core saw. Samples are of average metre length and not more than 2 metres length. Half core samples were cut and sent for analysis by an independent ISO certified laboratory (Intertek McPhar Laboratory) in Manila.
Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. The length of each drill run is recorded and the recover for each run calculated on site and checked again at the core shed. Certified reference standards and Sierra's field blank samples were each inserted into sample batches to assess the accuracy and precision of the ISO certified laboratory which assayed the samples. The half core from every 20th sample was sawn into two and the two quarter core samples submitted for analysis separately.
Aspects of the determination of mineralisation that are Material to the Public Report. In cases where 'industry standard' work has been done this would be relatively simple (e.g. 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (e.g. submarine nodules) may warrant disclosure of detailed information. Diamond drill core of PQ and HQ diameter were cut in half and half core samples submitted to the Laboratory. Sample intervals generally average 1 metre although occasionally slightly longer or shorter intervals were used where changes in lithology, core size or core recovery required adjustments.
Drilling techniques Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc.). Drilling was by PQ and HQ diameter, triple tube diamond core. The down hole orientation of the majority of the holes reported were surveyed with a Reflex gyro down hole instrument due to the highly magnetic mineralisation. The core was not orientated.
Drill sample recovery Method of recording and assessing core and chip sample recoveries and results assessed. Core recovery is initially measured on site by trained technicians and again in the core shed by the core shed geologist. Any core loss is measured, the percentage calculated and both are recorded in the Geotech log for reference when assessing assay results. In instances where core breaks off before the bottom of the hole leading to "apparent poor recovery" followed by a core run of > 100 % recovery the adjustment is made in the records.

Core loss is not a significant problem at Mabilo as the majority of the mineralisation is in fresh rock where recoveries are greater than 90%. The mineralisation occurs in wide intersections (generally over 30 metres thick) of massive magnetite skarn with relatively uniform copper and gold grades. Core loss occurs in narrow fracture zones but is not considered to be a significant problem ie the core lost in fracture zones is unlikely to have been significantly higher or lower grade than the surrounding material. In the weathered hematitic oxidised zones some core loss is unavoidable, but overall recovery is generally > 90% and the core loss is volumetrically minor in the large homogenous mineralised zones. In areas of poor recovery the sample intervals are arranged to coincide with drill runs thus areas of different core loss percentage are specific to individual samples which can be assessed when interpreting analytical results and modelled in future resource estimation studies.  Where an area of 100% core loss is identified the sample intervals are marked to each side of the zone and the zone is designated "No core" and assigned zero value in the various log sheets and geochemical database.
Measures taken to maximise sample recovery and ensure representative nature of the samples. All care is taken to ensure maximum recovery of diamond core. Drillers are informed of the importance of core recovery and joint venture earn-in for metres drilled is linked to core recovery to provide an incentive for the drillers to maximise core recovery. Any areas of poor core recovery are sampled separately thus assay results can be directly related to core recovery.
Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. There is no discernible relationship between core recovery and grade as the grade of the skarn bodies is relatively uniform over significant lengths and the copper and gold grades are not related to clay and fracture zones which are the main causes of core loss.
Logging Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. The diamond drill core is logged in significant detail in a number of logging sheets including a geological log, a structural log, a geotechnical log and a magnetic susceptibility log for the entire drill hole. All intervals sampled are logged individually in a separate quantitative log with percentages of the different mineral species being recorded. The logging is appropriate for mineral resource estimates and mining studies, neither of which are reported herein.
Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc.) photography. Most of the geological logging is a mixture of qualitative (descriptions of the various geological features) and quantitative (numbers and angles of veins and fracture zones, mineral percentages etc). The Quantitative Mineralisation log and the Magnetic susceptibility log are quantitative. Photos are taken of all core (both wet and dry) prior to the core being cut.
The total length and percentage of the relevant intersections logged. All core, including barren overburden is logged in the various logging sheets noted above apart from the Quantitative Mineralisation Log in which only the mineralised intervals sent for geochemical analysis are logged in greater detail.
Sub-sampling techniques and sample preparation If core, whether cut or sawn and whether quarter, half or all core taken. The average sample lengths are approximately one metre but may be slightly more or less to coincide with lithological breaks, changes in core diameter and any areas of different core recovery.

All core from mineralised zones and the immediate surrounding rocks is initially sawn in half to provide a better surface for geological logging. Half core is bagged for analysis and the other half retained for reference and or further testwork. One in every 20 samples of half core is sawn again to produce two quarter core duplicate samples which are submitted to the laboratory separately with different sample numbers.
If non-core, whether riffled, tube sampled, rotary split, etc. and whether sampled wet or dry. All sampling data reported is from diamond drill core.
For all sample types, the nature, quality and appropriateness of the sample preparation technique. All core samples are sent to an ISO certified independent laboratory where samples are dried, crushed, riffle split and pulverised to 95% of the sample passing a 75μm sieve.
Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. Certified reference standards and Sierra's field blank samples were each inserted into sample batches in the ratio of one standard for every 40 samples and one blank for every 20 core samples to assess the accuracy, precision and methodology of the ISO certified laboratory which assays the samples. In addition one in every 20 core sample was cut into 2 quarter core duplicate samples to assess the grade variability within the drill core. Each quarter core duplicate is analysed twice by the laboratory. A record of results from all duplicates, blanks and standards is maintained for ongoing QA/QC assessment. In addition, the laboratory which analysed the samples conducted their own extensive check sampling as part of their own internal QA/QC processes which is reported in the assay sheets. Examination of the QA/QC sample data indicates satisfactory performance of field sampling protocols and the assay laboratory.
Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. Every 20th sample was cut into 2 quarter core duplicate samples to assess the grade variability of the drill core. A repeat assay is done on every duplicate sample to better assess the variability of the duplicate samples. A record of results from all duplicates, blanks and standards and repeat samples is maintained for ongoing QA/QC assessment. The variance in the duplicate sampling of the assay results reported herein are considered acceptable.
Whether sample sizes are appropriate to the grain size of the material being sampled. The magnetite skarn mineralisation occurs in large bodies of fine grained magnetite with chalcopyrite (containing gold) disseminated through the magnetite body. The sample size of approximately one metre core length is suitable in respect to the grain size of the mineralisation.
Quality of assay data & lab tests The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. The assay techniques used for the assay results reported herein are international standard and can be considered total. Samples were crushed to 95% 10mm and a 1.5 Kg sub-sample riffle split and pulverized to 95%75 um. Gold was analysed by 50 g fire assay and the other elements by ICP-MS or ICP-OES following a four acid digest.  The laboratory which analysed the samples conducted their own extensive check sampling as part of their own internal QA/QC processes which is reported in the assay sheets. Examination of all the QA/QC sample data indicates satisfactory performance of field sampling protocols and the assay laboratory indicating acceptable levels of precision and accuracy.
For geophysical tools, spectrometers, handheld XRF instruments, etc., the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. No geophysical tools were used for any analysis reported herein. Magnetic susceptibility readings are taken of all core but are only used in magnetic modelling to plan drill hole positions and are not used to estimate magnetite or Fe content.
Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established. One field blank sourced and prepared by Sierra from a local quarry and one certified reference standard sample are routinely submitted with the core samples. In addition one in every 20 core samples is cut into 2 quarter core samples which are submitted independently as a check on how representative an individual core sample is. The results for the assays reported herein are deemed to be acceptable. Batches of coarse reject and pulp samples returned from the laboratory are sent to a second laboratory on a periodic basis for umpire analysis.
Verification of sampling and assaying The verification of significant intersections by either independent or alternative company personnel. The geochemical results reported herein and the calculated averages for different lithology types were independently checked and calculated by two company personnel.
The use of twinned holes. No twinned holes have been carried out
Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. Data documentation, verification and storage is conducted in accordance with the Sierra's Standard Operating Procedures Manual for the Mabilo Project. The diamond drill core is logged in significant detail in a number of separate excel template logging sheets including:
1] a Geological log of all core, recording mineralogy, lithology, alteration, degree of oxidation and mineralization;
2] a Structural log of all core, recording alpha angles, structure and vein types and quantity and vein  infill minerals;
3] a Geotechnical log of all core recording RQD, defects, fabrics;
4] a Quantitative Mineralisation log of all intervals sampled.
5] a magnetic susceptibility log of all core;
6] bulk density data for selected samples representing domains identified by the project geologist.

All logging sheets are either recorded directly or transcribed onto excel spread sheets which are validated by both the Project Geologist and Company data base manager and archived separately as well as being combined into a dedicated data base along with the assay results. All logging data is validated and archived and is available for future reference. Hard copies of all logging sheets are kept at the Project office in Daet.
Discuss any adjustment to assay data. The results from the two quarter core duplicate samples are averaged before being entered into the geochemistry database and reported so that all geochemical data represents the results from half core samples. The assay results reported herein include averages of the duplicate samples. Samples with assay grades below detection level are assigned a value of half (50%) the lower detection level value when averaging intervals for reporting. Standard checks and repeat samples from the laboratory are scrutinised and retained in an archive of all assay sheets received as well as in a QA/QC database but are not included in the primary geochemical database. No top cuts of assay data have been conducted in the results reported.
Location of data points Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. Drill hole collars are initially sited with a hand held GPS with an accuracy of +/- 5 metres. Completed holes are surveyed by an independent qualified surveyor on a periodic basis using standard differential GPS (DGPS) equipment achieving sub decimetre accuracy in horizontal and vertical position.

All but one of the holes reported herein have not been surveyed with a differential GPS as indicated in Appendix 1. Ten of the holes reported have been surveyed down hole with a Reflex gyroscopic down hole instrument. Short vertical holes and holes which were abandoned or failed to intersect mineralisation were not surveyed.
Specification of the grid system used. Co-ordinates are reported on a UTM Grid;  WGS84 (51N).
Quality and adequacy of topographic control. The Mabilo area is relatively flat with total variation in topography less than fifteen (15) metres. The collar elevation for all but one drill holes reported herein are based on a comparison with adjacent surveyed collars and are considered accurate to +/- two metres.
Data spacing and distribution Data spacing for reporting of Exploration Results. The drill hole assay results reported herein are from drill holes, mostly on a nominal 50 metre spacing aimed at determining the extent of the magnetite skarn mineralisation.
Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. The drill holes are at variable spacing aimed at confirming the extent of the massive magnetite skarn zones indicated by modelling of ground magnetic and drill hole magnetic susceptibility readings. The drill hole spacing is sufficient in conjunction with ground magnetic data to establish the continuity of mineralisation reported herein. No estimated grades or resource estimations are included in the report.
Whether sample compositing has been applied. No compositing of intervals in the field was undertaken.
Orientation of data in relation to geological structure Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type The assay data reported herein occurs in large magnetite replacement bodies. There are no known internal structures effecting the grade distribution thus the sampling reported herein is not biased.
If the relationship between the drilling orientation and the orientation of key mineralised structures is considered to have introduced a sampling bias, this should be assessed and reported if material. There is no bias in the sampling reported herein apart from vertical holes which in places intersect dipping mineralised zones thus having an apparent thickness greater than the true thickness. The orientation of all holes and the interpreted orientation of the mineralisation are discussed in the report.
Sample security The measures taken to ensure sample security. Chain of custody is managed by Sierra employees. Core trays are kept at the drill site under constant watch by Company employees prior to being transported from the drill site by Company employees in a Company vehicle to the core shed where core is logged, sawn and prepared for dispatch.

Remaining core is kept in the Company core yard which is in a secure compound at the Company regional office in Daet town and guarded at night.

Samples are sent directly from the core shed to the laboratory packed in secured and sealed plastic drums using either Company vehicles or a local transport company. A standard Chain of Custody form is signed by the driver responsible for transporting the samples upon receipt of samples at the core yard and is signed by an employee of the laboratory on receipt of the samples at the laboratory. Completed forms are returned to the Company for filing.
Audits or reviews The results of any audits or reviews of sampling techniques and data. The sampling techniques and QA/QC data are reviewed on an ongoing basis by Company management and independent consultants. The writer of this report is an independent consultant who has reviewed all sample handling techniques and considers them to be of industry standard and appropriate.

Reporting of Exploration Results:

Criteria Explanation Commentary
Mineral tenement and land tenure status Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. The Mabilo Project is covered by Exploration Permit EP-014-2013-V and Exploration Permit Application EXPA-000188-V. Drilling activity the subject of this announcement is within EP-014-2013-V which was granted in July 2013 for two years, with the option to renew for an additional 4 years. EP-014-2013-V was issued to Mt Labo Exploration and Development Corporation ("Mt Labo"), an associate of Sierra. There is a 1% royalty payable on net mining revenue received by Mt Labo in relation to EP-014-2013-V.

Sierra and Mt Labo have entered into a joint venture agreement with Galeo Equipment and Mining Company, Inc ("Galeo") to partner in exploring and developing the Mabilo and Nalesbitan Projects.  Galeo can earn up to a 36% interest in the Projects, down to 200 metres below surface, by contributing approximately US$4,250,000 of exploration drilling and management services for the Projects over a 2 year period.

In November 2013, Sierra and Galeo signed a Memorandum of Understanding ("MOU") setting out proposed changes to the joint venture agreement to remove the depth limit of 200m from the agreement and provide for additional drilling of 5,000m below 200m. The MOU also provides for Galeo to be granted its 36% interest up front with the ability for Sierra to claw-back any interest deemed not earned at the end of the claw-back period. The amendments to the JV Agreement are subject to Sierra shareholder approval.

Sierra has also entered a second MOU with Galeo whereby Galeo can earn an additional 6% interest in the joint venture by mining the initial 1.5Mt of waste at Mabilo or Nalesbitan. The MOU is subject to a number of conditions precedent, including Sierra shareholder approval.

There are no native title or Indigenous ancestral domains claims at Mabilo.
The security of the tenure held at the time of reporting along with any known impediments to obtaining a licence to operate in the area. The tenure over the area currently being explored at Mabilo is a granted Exploration Permit which is considered secure.
Exploration done by other parties Acknowledgment and appraisal of exploration by other parties. The only significant previous exploration over the Mabilo project area was a drilling program at another site within the tenement and a ground magnetic survey. Sierra has reported this data in previous reports to the ASX and used the ground magnetic survey as a basis for initial drill siting. Subsequently Sierra conducted its own ground magnetic survey with closer spaced survey lines and reading intervals which supersedes the historical program. There was no known previous exploration in the area where the drilling reported herein was conducted.
Geology Deposit type, geological setting and style of mineralisation. Mineralisation at Mabilo can be defined as a magnetite-copper skarn which developed where the magnetite-copper mineralisation replaced beds of calc-silicate skarn (predominantly garnet skarn) in the Eocene age Tumbaga Formation.
Drill hole Information A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes:  
  • easting and northing of the drill hole collar 
  • elevation or RL (Reduced Level - elevation above sea level in metres) of the drill hole collar
  • dip and azimuth of the hole  
  • down hole length and interception depth   
  • hole length.
The sampling and geochemical information contained in this report is from the second phase of drilling at Mabilo. The easting, northing, elevation, dip, azimuth and end of hole depth of the holes reported herein is documented in a table within the report. Down hole depths and widths of intersections are documented in the text. The easting, northing, elevation and orientation for all holes drilled at the Mabilo project has been reported in this and previous reports to the ASX.
If the exclusion of this information is justified on the basis that the information is not Material and this exclusion does not detract from the understanding of the report, the Competent Person should clearly explain why this is the case. All relevant data has been reported.
Data aggregation methods In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g. cutting of high grades) and cut-off grades are usually Material and should be stated. Assays of samples of different lengths are weighted for their length when averaging assays for the large intervals reported herein. Where any element in an interval reported is below detection level it is assigned a value of half (50%) of the lower detection level when averaging mineralised intervals for reporting. Intervals with no core recovery are assigned zero value when averaging results. No top or bottom cuts have been made to the assay data.

The Mabilo skarn mineralisation is large with a relatively uniform grade. Higher or lower grade zones with the mineralised bodies are wider than sample intervals. The average grades reported herein are based on sample widths of average 1 metre width. Where an average grade contains a high grade intersection the high grade intersection has also been reported.
Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail.
The assumptions used for any reporting of metal equivalent values should be clearly stated. No metal equivalent grades are reported herein.
Relationship between mineralisation widths and intercept lengths These relationships are particularly important in the reporting of Exploration Results.  
If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported.

If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (e.g. 'down hole length, true width not known').
The holes reported herein have been drilled both vertically and inclined. The orientation of the mineralised bodies is based on magnetic modelling and drill hole results which indicates that much of the mineralisation is variably dipping to the south-west.

The interpreted orientation of the mineralised bodies is based on magnetic modelling and drill hole data and is documented in the report. The fact that the intersections are in a dipping body and therefore not true widths is reported and no intervals reported herein can be assumed to be a true width of the mineralisation.
Diagrams Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. Plan view maps showing locations of all holes reported along with magnetic models and areas of interpreted mineralisation are included in the report.
Balanced reporting Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. The report documents the assay results of intersections of the mineralised magnetite skarn. Low grade sample results from adjacent rocks outside the mineralised body are reported. Barren or very low grade results are not reported. Assays from drill holes which did not intersect mineralisation are not reported but their location is shown on plans in the report.
Other substantive exploration data Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. All meaningful exploration data concerning the Mabilo Project has been reported either in previous reports to the ASX or in the current report to which this table is attached.

The report notes visual occurrence of chalcopyrite in holes MDH-52, 53, 54, 55 and 57 for which assay results have not been received. These are based on the writers own personal observation with respect to visible chalcopyrite observed in other holes.
Further work The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling).

Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive.
The attached report is an interim report on an ongoing drilling program. Areas of future drilling are discussed where appropriate in the text and the magnetic modelled mineralised bodies which are the target of the on-going drilling are outlined in the figures included in the report.



Image with caption: "Figure 1. RTP ground magnetic image with the modeled South, North and East bodies. The Venida area was not surveyed by ground magnetics due to an existing small scale mining operation which has subsequently ceased operations. (CNW Group/RTG Mining Inc.)". Image available at:

Image with caption: "Figure 2. Revised magnetic model (blue frame), RTP ground magnetic image and completed and current drill holes on the South Body. Collars of holes reported herein are shown as yellow dots. (CNW Group/RTG Mining Inc.)". Image available at:

Image with caption: "Figure 3. Modelled magnetite body shown in blue frame, drill hole locations and interpreted strike extension of magnetite-chalcopyrite mineralisation shown by shaded background. Holes reported below shown with yellow collar. (CNW Group/RTG Mining Inc.)". Image available at:

Image with caption: "Figure 4. East Body revised magnetic model and drill hole locations (CNW Group/RTG Mining Inc.)". Image available at:

SOURCE: RTG Mining Inc.

For further information:

Chairman - Michael Carrick   
Tel: +61 8 6489 2900    
Fax: +61 8 6489 2920   
CEO - Justine Magee
Tel: +61 8 6489 2900
Fax : +61 8 6489 2920

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RTG Mining Inc.

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