Quality Assurance/Quality Control Protocols
Northern Gold Mining Inc. (“Northern Gold” “NGM”) has Quality Assurance/Quality Control (“QA/QC”) protocols in place for all its exploration and development drilling. At the Garrison Gold Property, Northern Gold is conducting exploration for additional gold mineralization outside those areas containing NI 43-101 compliant gold resources, as well as the development and expansion of gold mineralization in all resource categories within areas containing NI 43-101 compliant gold resources. At the Garrison Gold Property industry standard QA/QC protocols were implemented with the start of Northern Gold’s drilling on the Property in October 2009. Since then, from time to time, improvements and adaptations have been implemented to improve the overall effectiveness of those protocols.
Diamond drilling at the Garrison Gold Property is currently being undertaken by two diamond drill contractors and Northern Gold has specified that all holes be collared using NQ-size core (47.6 mm or 1.87 inches), which provides a good sample size and also allows for two size step downs should problems be encountered in a hole. In addition, the equipment must be capable of drilling a minimum distance of 700 meters downhole.
Major Drilling Group International Inc. of Winnipeg, Manitoba has been drilling on the Property since the 2009 drill program began in October of 2009. In October 2010, at NGM’s request, Major added a second drill rig and has continued drilling with two (2) Atelier VD5000 drill rigs since that time. In August 2011, NGM added two additional drill rigs, bringing total drill rigs on the Garrison Gold Property to four. Asinii Drilling of Notre-Dame-Du-Nord, Quebec was awarded the contract for the last two drill rigs and are drilling with two (2) Usinage Marcotte Inc. HTM2500 drill rigs.
Sample security and chain of custody starts with the removal of core from the core tube and boxing of drill core at each drill. The boxed core remains under the custody of the drillers until it is transported from the drill to the secure Core Shack facility by either the drill contractor or one of the Company’s designated personnel. At the Core Shack core boxes are opened and inspected to ensure correct boxing and labeling of the core by the drill contractors then re-closed. The core is stored securely at the company’s core processing facility until it is moved into the Core Shack for processing.
Processing of the core starts with the calculation and recording of the percent core recovered and the Rock Quality Designation (“RQD”), followed by a quick lithologic log as a reference check for comparison with the Photonic Knowledge (“PK”) lithology using hyperspectral imaging (Please see Press Release dated December 7, 2011.) Next the core is photographed with a high-resolution camera, capturing RAW digital images that will later be converted to either a JPEG or TIFF formatted image. This high-resolution photography produces a digital image with a resolution between 20 and 25 mega-pixels, assuring images of sufficient quality to enable re-logging on a monitor at larger than life size. Three boxes of core are photographed at the same time, first photographing the core on one side and then rotating the core 180 degrees for a second image. The core is then securely stored on site and placed in the queue for hyperspectral imaging. Hyperspectral imaging provides a detailed analysis and false-colour image of the various hydrothermal alteration types known to be associated with gold mineralization in the Garrcon Deposit. PK includes QA/QC imaging checks in every scan completed.
Following the PK hyperspectral imaging, the core is marked and tagged for sampling and splitting. Sample lengths are normally one meter, unless there is a geological reason to shorten the sample interval. Core marked for splitting is split using a diamond core saw with a mounted jig to assure the core is split equally. One-half of the core is sent to an analytical laboratory for analysis. The remaining one-half of the core is retained and incorporated into the on-site core library and for any metallurgical test work that may be required. Duplicate samples are taken every 20th sample, each with its own unique sample number in order that all of Northern Gold’s duplicate are blind to the analytical laboratory. Duplicates alternate between pulp duplicates and core duplicates. Pulp duplicates are obtained by taking a second 300-gram riffle split from the crushed core, resulting in two 300-gram pulps from each sample interval selected for pulp duplicate analysis. Thirty-gram samples from each 300-gram pulp are assayed separately. Core duplicates are obtained by taking all of the remaining core from the selected sample interval and having it processed identically to the normal half-core samples. While using both core halves from the selected sample intervals does not leave any core in that interval for reference purposes, this procedure yields improved correlation between duplicate core samples as compared to using quarter-core duplicates, as was the previous practice.
In addition to duplicates, Northern Gold inserts blank samples and certified gold standard samples at a rate of 5% of each sample type. Normally, four different gold standards are used and are randomly selected prior to insertion into the sample stream.
The process described above is standard procedure for all exploration drilling conducted outside of the resource footprint, defined by A.C.A. Howe International Ltd. (“Howe”) in their independent NI 43-101 Technical Report filed on SEDAR August 8, 2011. Within that resource footprint, whole core analysis is utilized in preference to half-core analysis. The benefits of and rationale for implementing whole core analysis includes:
- It is statistically proven that a larger sample size results in more reliable analyses, particularly in gold deposits.
- More reliable analyses yield a higher confidence level in the resource estimation.
- The successful implementation of PK’s hyperspectral imaging process produces far more and better lithology and alteration data than can be obtained by conventional core logging, reducing the need to retain half of the split core as a reference source.
- The current physical core library within the Howe resource footprint contains nearly 200 drill holes, which Northern Gold believes is more than adequate for any future needs.
- The drill core photographic record is of sufficient quality to provide answers to any question that may arise regarding the lithology, alteration, or mineralization.
Chain of Custody protocols require the signing and maintenance of tracking logs and receipts when samples are shipped from the Property, and when they are picked up from analysis laboratories and delivered to another laboratory or returned to the Property. When utilizing commercial transportation to ship from the Property, all shipping sacks are sealed with a numbered tag, the removal of which is recorded upon receipt by the receiving analytical laboratory.
The Company utilizes the services of two analytical laboratories for assaying. One laboratory is Expert Laboratories (“Expert”), an accredited laboratory (PTP-MAL – Accredited by Standards Council of Canada – In full accord with ISO/IEC Guide 43-1 "Proficiency Testing by Interlaboratory Comparison”) in Rouyn-Noranda, Quebec. The second laboratory is SGS Canada Inc. (“SGS”) a certified laboratory (ISO/IEC 17025), in Toronto, Ontario.
NGM utilizes the services of both laboratories for primary gold analyses. Both laboratories follow nearly identical procedures in fire assaying for gold as is described in more detail below. All remaining half core not submitted for assay is stored at the Garrison Gold Property and included in the current core library for reference and any future testwork. Following completion of assaying all unused crusher rejects and pulps are returned to the Property for dry and secure long term storage.
All sample intervals where visible gold, or a mineral that is believed to be visible gold, is observed are submitted for lead fire assaying using the metallic screen procedure followed by a gravimetric finish at both Expert and SGS. When using this procedure, the entire sample is pulverized and screened through a 100-mesh screen. The screen oversize is lead fire assayed in total, while the screen undersize is mixed and three duplicate 30 gram samples are lead fire assayed using a gravimetric finish.
Fire assay analytical procedures for gold at Expert are as follows:
- The total sample submitted is crushed to 90% passing 10 mesh (2.0 mm).
- A 300 gram sub-sample is riffle split and pulverized to 90% passing 200 mesh (75 micron).
- A 30-gram pulp sample is lead fire assayed with an ICP (inductively coupled plasma) geochemical finish with a lower detection limit of 0.005 g/t.
- 10% of all samples are assayed in duplicate and one blank and one standard are included in every 28 samples.
- All samples that assay greater than 3 gm/t are re-assayed using another 30-gram sample with a gravimetric finish.
Following completion of fire assaying Expert packages up all remaining pulps and ships the pulps to the SGS laboratory in Toronto for CN (cyanide) soluble assaying and geochemical analyses. Coarse rejects are returned to the Project site for dry and secure storage.
Fire assay analytical procedures for gold at SGS for are as follows:
- The total sample submitted is crushed to 75% passing 10 mesh (2.0 mm).
- A 250 gram sub-sample is riffle split and pulverized to 85% passing 200 mesh (75 micron).
- A 30-gram pulp sample is lead fire assayed with an ICP geochemical finish with a lower detection limit of 0.005 g/t.
- 10% of all samples are assayed in duplicate and one blank and one standard are included in every 28 samples.
- All samples that assay greater than 3 gm/t are re-assayed using another 30 gram sample and given a gravimetric finish.
All CN soluble and geochemical analyses are completed at the SGS laboratory in Toronto. CN soluble analyses are completed as follows:
- All drill samples submitted for fire assay at either Expert or SGS are re-assayed at SGS using a 1% hot cyanide solution and shaken for an hour followed by decantation with an AAS (atomic absorption spectroscopy) finish.
All multi-element geochemical analyses are completed at the SGS laboratory in Toronto. These analyses are completed as follows:
- All drill samples submitted for fire assay at either Expert or SGS are analyzed at SGS for a 32-element suite of minerals.
- The multi-element analysis is conducted using 4-acid digestion and finished using ICP and OES (optical emission spectroscopy) analyses.
Northern Gold completes check analyses of gold assays at a rate of approximately 5% of all samples submitted for gold analysis. Expert analyses are checked at SGS and SGS analyses are checked at Expert.
When multiple drills are being used, each drill is assigned a series of 10 sequential numbers with which to designate drill holes. This ensures that hole locations and core boxes are properly marked and identified. When a drill completes 10 holes, that drill is assigned another 10 sequential numbers. This means that drill results will not be disclosed in numerical order.
The technical aspects of these QA/QC Protocols have been reviewed and approved by Michael P. Gross M.S., P.Geo., Vice President Exploration for Northern Gold Mining Inc., who is a “Qualified Person” as defined by NI 43-101 for project.