SIERRA MINING LIMITED 
By The Board of Sierra Mining Limited ("Sierra") is pleased to present the assay results for hole MDH-16, which was the first hole of the current drilling program aimed at testing the conceptual South B target zone.
As discussed in the ASX announcement dated 14 October 2013, hole MDH-16 intersected magnetite skarn from 106 to 159 m. The hole has now been assayed and graded:
53 metres at 5.31 g/t Au, 3.14 % Cu, 11.0 g/t Ag and 51.06% FeThe grade of the magnetite skarn intercept is the highest recorded to date at the Mabilo project. Hole MDH-16 is a vertical diamond core hole located at 1559835 N, 476136 E and 121 m RL
(WGS 84, 51N). Note that the true width of the intersection will be less than 53m as the body is
interpreted to dip between 40-50° in this area.
The intersection contains abundant chalcopyrite similar to other mineralised intervals at Mabilo in addition to bornite, which has not been recognised in previous mineralised intersections. The higher gold to copper ratio in this intersection is attributed to the presence of bornite, which can contain significantly higher levels of Au than chalcopyrite. Although the mineralised intersection is weathered and depleted in Cu and Au up dip in hole MDH-04, no evidence of supergene enrichment is recognised in MDH-16 and the mineralisation is considered primary.
The magnetite skarn zone in MDH-16 is bound by zones of intense pyrite-arsenopyrite veining and brecciation from 104.15 to 106 metres and a thicker zone from 159 to 177.68 m which graded 0.27 g/t Au and 0.22% Cu over 18.68 metres. The pyrite-arsenopyrite post-dates and in places replaces the magnetite skarn, with the grades recorded in the pyrite-arsenopyrite zone being related to the presence of relict Cu-Au bearing magnetite skarn clasts within the pyrite- arsenopyrite zones. Zones of less intense pyrite-arsenopyrite veining also occur within the magnetite skarn but are not volumetrically significant.
The MDH-16 mineralised intercept is considered highly significant in the on-going exploration of the Mabilo skarn mineralisation, as it provides the first confirmation of the magnetic model for the South B body, and also confirms the presence of extensive Cu and Au mineralisation in the South B body.
Enquiries: Matt Syme, Managing Director, +61 8 9322 6322MDH-05 ;62 m at 2.66 glt Au,
2.76% eu,10.3 g/tAg, 48.82% Fe
MDH-1O ;64.4 m at 2.25 glt Au,
2.28% Cu,10.2 g/tAg, 45.25% Fe
MDH-04 ;22 m at 0.44 glt Au,
0.20 % Cu ,1.3 g/t Ag,45.67 % Fe
Phase 1 drill hole collar Phase 2 DDH completed Phase 2 DDH current Phase 2 DDH planned
200.0 meters
RTP magnetic image showing 2D modeled magnetite skarn zones and drill hole locations.
Appendix 1: New Drilling Results at the Mabilo Project included in this reportSampling Techniques and Data: Drill Hole MDH-16, Mabilo Project
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 NQ diameter which was cut with a diamond core saw. Samples are mostly of 1 metre length or less (average 0.92 m, maximum 1.55 m). Cut half core samples were 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 half core sample is assumed to be representative of the full core sample. Duplicate samples (two quarter core samples from the same interval) are collected for every 20th sample and 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.
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 NQ diameter were cut in half and half core samples submitted to the Laboratory. Sample intervals were generally 1 metre although occasionally slightly longer or shorter intervals were used where changes in lithology, core size or core recovery required adjustments. The maximum sample length for assays included in this report is 1.55 metres and the average sample length 0.92m.
Samples were crushed and pulverized (95%<75 um). Gold was analysed by 50 g Fire assay and other elements by ICP-MS or ICP-OES following a 4 acid digest.
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, HQ and NQ diameter, triple tube diamond core. The hole for which data is being reported is vertical and relatively short thus down hole orientation surveys were not conducted. 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 in the hole reported herein as recoveries are generally over 90% and close to 100% in the fresh magnetite skarn which was sampled. The mineralisation occurs in large bodies (+50 metres thick) of relatively uniform grade thus small zones of poor core recovery are not overly significant ie they are unlikely to have been significantly higher or lower grade than the surrounding material.
Where a particular drill run has lower recovery the sample interval is adjusted to coincide with the drill run thus recovery can be directly correlated to assay data when assessing the results.
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 payment or joint venture earn-in for metres drilled is linked to core recovery to provide an incentive for the drillers to maximise core recovery.
Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of
There is no relationship between core recovery and grade as the grade of the skarn bodies is relatively uniform over significant widths (+50m). The Cu, Au and Ag grade is related to the presence of disseminated chalcopyrite and bornite and is not
3
Criteria Explanation Commentary
fine/coarse material. related to fractures and faults which are the main causes of core loss and reduced recovery.
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, a quantitative skarn mineralisation log and a magnetic susceptibility log which 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 (number of, width of and angles of veins, estimated percentages of various minerals etc). The quantitative skarn mineralisation log and the Magnetic susceptibility log are quantitative. Photos are taken of all core (both wet and dry) which can be considered quantitative.
The total length and percentage of the relevant intersections logged.
All core, including barren overburden and country rock is logged in the various logging sheets noted above.
Sub- sampling techniques and sample preparation
If core, whether cut or sawn and whether quarter, half or all core taken.
Sample lengths are generally one metre but may be slightly more or less to coincide with lithological breaks, changes in core diameter (PQ/HQ/NQ) 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 collected for analysis and the other half retained for reference and or metallurgical 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 sample results reported herein is of 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 and pulverised to
95% of the sample passing a 75
