RNS Number : 3937P
Ortac Resources Limited
17 February 2016

Ortac Resources Ltd / Epic: OTC / Market: AIM / Sector: Mining & Exploration

17 February 2016


Update on Andiamo Exploration Ltd's Operations in Eritrea

Ortac Resources Ltd ("Ortac" or the "Company"), the AIM listed exploration and mine development company, announces that its exploration partner in Eritrea, Andiamo Exploration Ltd ("Andiamo"), in which it holds a 25% equity interest, has provided an update on its activities within its 253km2 Haykota Exploration License area.



·     Volcanogenic Massive Sulphide ("VMS") occurrence confirmed at Hoba with the completion of a second-round 2,000m core drill program; and

·     Maiden JORC Resource Estimate Completed for Yacob Dewar.

Andiamo, together with its Joint Venture partner Environminerals East Africa Ltd ("EEA"), has recently completed a 2,000m diamond drilling programme on the Hoba prospect, located in the northern part of the Haykota Exploration License area that has confirmed the presence of a VMS deposit.

Table 1. Selected Hoba copper intersections

Drill Hole Number

From Downhole (m)

Intersection (m)

Average grade (Cu %)

















The primary intention of this drilling programme was to establish the limits of the mineralisation and to detect whether the intensity of the mineralisation is zoned (i.e. "vectoring" the VMS).  The massive sulphide intersections display very high concentrations of sulphur and iron  (often around 50% each) which support the analysis of this being a typical massive sulphide lens. The present drilling results follow a successful 2015 program of stream sediment sampling, ground mapping, surface sampling, a hand-dug trenching program and an initial 1,000m scout diamond drill programme in the Hoba area.

In addition to the work carried out at Hoba, Andiamo also commissioned Denny Jones Pty Ltd of Brisbane, Australia to estimate the Yacob Dewar Mineral Resource in compliance with JORC standards for both the oxide gold and the adjacent copper resources.

Table 2. Yacob Dewar - Gold and Copper JORC Mineral Resource


Tonnes (t)

Au (g/t)

Au (oz)

Tonnes (t)

Cu (%)

Cu (t)















Commenting on today's news, Vassilios Carellas, Ortac's CEO, stated: "These results from the northern part of the license offer further encouragement that another VMS system is present in this part of the license area, and that it follows a trend where other economic VMS deposits have already been discovered and have started, or are in the process of starting, the production phase.  At only 20km from Ashelli, the Hoba VMS system follows same geological sequence as the recent VMS discovery at by Bisha Mining Share Company. Furthermore, the maiden JORC resource at Yacob Dewar provides a solid platform from which to explore and develop further resources in the southern part of the license area."

Joint Venture with EEA - the northern part of the Haykota License

The northern part of the Haykota Exploration Licence ("JV license area") is being explored under an agreement with Environmentals East Africa Ltd ("EEA"), whereby EEA may earn a 50% interest in discoveries in the northern part of this area by spending a total of US$2.0m by the end of March 2016. Andiamo believes that EEA's expenditure to date indicates that they will have earned this 50% interest by that time. Under the terms of the original agreement between the companies, EEA may then earn a 75% interest in projects in the JV license area by completing a Technical and Economic Assessment of an equivalent standard required for a Mining License application.

An airborne geophysical programme conducted by Andiamo in 2010 shows anomalous electromagnetic responses from the JV licence area. Many of these targets are also coincident with anomalous gravity highs identified from a ground gravity survey, which are typical of VMS deposits.

EEA has remodelled the airborne geophysics and financed the drilling of an initial two targets at Hoba. There are several other promising targets in this northern area, which have yet to be fully investigated and the next steps in the Joint Venture will be to examine these in more detail.

The southern part of the Haykota Licence - the Yacob Dewar Mineral Resource

The gold mineralisation is contained within and around a "Silica-Barite" horizon (SBR), known to be the remnant of an underlying VMS lens that has been oxidised and eroded, dipping at about 50 degrees to the West. The SBR itself is composed almost entirely of silica sand, barite sand and kaolin, and is surrounded by a "halo" of progressively lower grade gold mineralisation. Outcropping, or beneath shallow soil cover, there are high-grade areas of the SBR which could potentially be mined at an early stage to recover the capital costs of a mining operation.

The Mineral Resource is already constrained within a potential Pit Shell, as required by JORC 2012. The depth of the currently identified oxide gold mineralisation is present to an approximate depth of 40-45m from the surface, over about 1.1km of strike length. The gold mineralisation is contained in an outcropping and relatively wide zone (typically 10m wide). Therefore, the Strip Ratio and amount of waste removal is likely to be relatively low. The oxidised rock appears to be soft enough to permit "ripping" initially, rather than drill-and-blast, which may also reduce operating costs.

Some 2km to the North East of the Yacob Dewar deposits, a further outcrop of the SBR has been identified at the Ber Gebay occurrence. Andiamo has traced it over 600m towards Yacob Dewar.

To the West (i.e. in the hanging wall) of the observed gold deposit at Yacob Dewar, an oxide copper zone has been identified. This is likely to be the copper present initially in the VMS horizon, but which has been leached in the very acid environment at the oxide/sulphide interface and has subsequently been transported to the West in solution and precipitated. The full extent of this oxide copper mineralisation has not yet been determined.


The information in this press release is based on information provided by Andiamo Exploration Ltd in the Chief Executive Officer's letter to the shareholders dated February 2016 and compiled on behalf of Ortac by Mr Vassilios Carellas. The Hoba drill assay results and the maiden JORC Mineral Resource estimate have not been independently verified by Ortac Resources Ltd. However, all assays are reported to have been prepared at Intertek Genalysis' sample preparation facilities in Asmara, Eritrea and assayed at their laboratories in Perth, Australia. All sample collection, storage, transport, security, sample preparation and assay methodologies employed by Andiamo have been previously audited by SRK Consulting (UK) Ltd in respect to National Instrument 43-101, as prescribed by the Canadian Exchange Commission, and are reported to be compliant as per its guidelines. Mr Carellas has reviewed the third party data on behalf of Ortac Resources and takes responsibility for the data and geological interpretation.  Mr Vassilios Carellas (BSc (Hons), MAusIMM) is the Chief Executive Officer of Ortac Resources Limited and has sufficient experience relevant to the style of mineralisation, type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined under the JORC Code. Mr Carellas consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears. 






Au - the chemical symbol for the element gold


Cu - the chemical symbol for copper


g/t - grams per tonne


Hangingwall - the underside of the wall rock overlying a vein or bed of ore


Indicated (Indicated Resource) - a part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed.


Inferred (Inferred Resource) - a part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes which may be limited or of uncertain quality and reliability.


JORC - the code for reporting of the Australasian Joint Ore Reserves Committee, which is sponsored by the Australian mining industry and its professional organisations. The code is widely accepted as a standard for professional reporting purposes for reporting of mineral resources and ore reserves.


m - metre, a unit of length as per the International System of Units.


Mineral Resource - a concentration or occurrence of material of intrinsic economic interest in or on the Earth's crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.


Mineralisation - the process or processes by which a mineral is introduced into a rock, resulting in a valuable or potentially valuable deposit.  It is a general term, incorporating various types; e.g., fissure filling, impregnation, and replacement.

Sulphide - a compound of sulphur and some other element. 


Volcanogenic massive sulfide ore deposits or VMS - a type of metal sulfide ore deposit, mainly Cu-Zn which are associated with and created by volcanic-associated hydrothermal events in submarine environments.




Ortac Resources Ltd

Vassilios Carellas (CEO)


+44 (0) 20 7389 9050

SP Angel (Nominated Adviser & Broker)

Ewan Leggat / Tercel Moore


Beaufort Securities (Joint Broker)

Jon Belliss / Elliot Hance

+44 (0) 20 3470 0470


+44 (0)20 7382 8300

Yellow Jersey (Media Relations)

Dominic Barretto / Aidan Stanley

+44 (0) 7584 085 670



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