Great News Guys
Coastal Gold releases Hope Brook NI 43-101 estimate
2013-12-04 05:12 PT - News Release
Dr. Bill Pearson reports
COASTAL GOLD REPORTS OVERALL INDICATED MINERAL RESOURCE INCREASES BY 110% TO 1.24 MILLION OUNCES GOLD AT HOPE BROOK GOLD PROJECT, NEWFOUNDLAND
Coastal Gold Corp. has released an update to its National Instrument 43-101 mineral resource estimate for the Hope Brook gold project in southwestern Newfoundland. This update incorporates results from the 5,951 metre (m) diamond drilling program completed in fall 2012 (see press releases dated December 11, 2012 and January 17, 2013) and the recently completed 4,075m drilling program (see press releases dated September 16 and 25, October 7 and 21 and November 1, 2013). The updated mineral resource estimate is presented in Table 1 below. Highlights are as follows:
Highlights
-- Overall indicated resource increased 110% to 1,239,000 ounces of gold -- Grade of overall indicated resource increased 30.2% to 1.93 g Au/t -- Indicated resource in potential open pit increased 128.8% to 966,000 ounces of gold -- Grade of indicated resource in potential open pit increased 37.4% to 1.70 g Au/t -- Indicated resource in potential underground increased 62.7% to 273,000 ounces of gold -- Grade of indicated resource in potential underground increased 25.9% to 3.76 g Au/t -- Almost all of the previous potential open pit inferred resource and 61% of the previous potential underground inferred resource was upgraded to the indicated category -- Resources are open along strike to the southwest and at depth with the Connector-240 Zone target that extends 1,200m along strike being a prime target for further drilling
Table 1: Mineral Resource for Gold, Hope Brook Gold Project as at December 4, 2013 (see page 4 for Notes on Methodology) Within constraining shell Below constraining shell @ 0.50 g Au/t cut-off @ 2.0 g Au/t cut-off Gold Gold Gold Gold Category Tonnes g/t (Oz) Tonnes (g/t) (Oz) Indicated 17,692,000 1.70 966,000 2,254,000 3.76 273,000 Inferred 230,000 0.89 7,000 1,101,000 3.71 131,000 Table 1: Mineral Resource for Gold, Hope Brook Gold Project as at December 4, 2013 (see page 4 for Notes on Methodology) Total Gold Category Tonnes Gold g/t (Oz) Indicated 19,946,000 1.93 1,239,000 Inferred 1,330,000 3.22 138,000
As shown in Table 2 below, total Indicated Mineral Resources increased 110% to 1,239,000 ounces of gold from the October 1, 2012 estimate. Most significantly, the average grade of the Indicated Mineral Resource increased 30.2% to 1.93 g Au/t. Almost 90% of the indicated resource is in the potential open pit. Almost all the entire previous potential open pit inferred resource has been upgraded to the indicated category. Mineral Resources are open along strike to the southwest and at depth with the Connector-240 Zone target that extends 1200m along strike being a prime target for further drilling.
Table 2: Comparison to October 1, 2012 Mineral Resource Estimate Mineral Resource Update December 4, 2013 Tonnes Grade (Millions) (g Au/t) Au Oz Totals Indicated 19.94 1.93 1,239,000 Inferred 1.33 3.22 138,000 Within Potential Pit Constraining Shell Indicated 17.7 1.70 966,000 Inferred 0.23 0.89 7,000 Below the constraining Shell Indicated 2.25 3.76 273,000 Inferred 1.10 3.71 131,000 Table 2: Comparison to October 1, 2012 Mineral Resource Estimate Increase/ Decrease Oz Mineral Resource Update October 1, 2012 Au Tonnes Grade (Millions) (g Au/t) Au Oz 110% Totals Indicated 12.4 1.48 590,000 Increase -- 74.9% Inferred 8.2 2.07 548,000 Decrease Within Potential Pit Constraining 128.8% Shell Indicated 10.6 1.24 422,000 Increase -- 98.4% Inferred 6.5 1.91 397,000 Decrease Below the constraining 62.7% Shell Indicated 1.7 2.99 168,000 Increase -- 13.2% Inferred 1.8 2.62 151,000 Decrease
Dr. Bill Pearson, P.Geo., President and CEO of Coastal Gold, stated: "We are delighted with the results of this mineral resource update, which not only significantly increased estimated resource ounces in the indicated category but also substantially increased the overall grades of the resource. This milestone will allow Coastal Gold to now complete a planned preliminary economic assessment (PEA), which is targeted for release in early 2014. We thank the Newfoundland and Labrador government for their support of our 2013 drilling program though the Junior Exploration Assistance program, which allowed us to complete additional drilling important for the resource definition."
Pearson continued: "This positive result was accomplished with two relatively limited, but highly targeted, drilling programs and is a credit to our exploration team lead by Coastal Gold's Chief Geologist, Dave Copeland, P.Geo. Our technical understanding of the project continues to grow and the mineral resources remain open along strike to the southwest and downdip. In addition to the new drilling, this model incorporates an updated geological interpretation utilizing a new structural model developed in the fall 2012 program as well as an improved definition of mineralized zones. In addition, the resource update incorporates a revised stope model and an updated mafic dyke dilution model. It also eliminates a number of historical holes that we believe, based on new drill data, significantly underestimated grades."
The mineral resource estimates are presented in Table 3 below at different cut-off grades to demonstrate the sensitivity of the mineral resources to change in grade. It is important to note that the bulk of the Indicated gold ounces are within a potential pit using a higher cutoff grade of 0.70 g Au/t.
Table 3: Mineral Resource Estimates at Different Gold Cut-off Grades, Hope Brook Gold Project - Within Constraining Shell Cut-off Tonnes Gold Gold Grade (millions) (g/t) (Oz) greater than 1.0 10.0 2.43 784,000 -- greater than 0.7 14.5 1.94 904,000 -- greater than Indicated 0.5 17.7 1.70 966,000 -- greater than 0.4 19.2 1.60 988,000 -- greater than 0.3 21.3 1.48 1,011,000 greater than 1.0 0.1 1.13 2,000 -- greater than 0.7 0.2 0.94 6,000 -- greater than Inferred 0.5 0.2 0.89 7,000 -- greater than 0.4 0.2 0.86 7,000 -- greater than 0.3 0.3 0.83 7,000 - Below Constraining Shell Cut-off Tonnes Gold Gold Grade (millions) (g/t) (Oz) greater than 4.0 0.7 5.59 130,000 -- greater than 3.0 1.4 4.55 203,000 -- greater than Indicated 2.0 2.3 3.76 273,000 -- greater than 1.5 2.9 3.32 308,000 -- greater than 1.0 5.4 2.31 403,000 greater than 4.0 0.4 4.89 65,000 -- greater than 3.0 0.8 4.24 104,000 -- greater than Inferred 2.0 1.1 3.71 131,000 -- greater than 1.5 1.3 3.34 143,000 -- greater than 1.0 3.0 2.14 206,000
The updated mineral resource is based on 689 diamond drill holes totaling 141,863 m of historic and recent drilling. This includes 47 surface diamond drill holes totaling 10,026 metres completed by Coastal Gold from October 2012 to November 2013. Mineral Resources have been estimated within a constraining pit shell at a cut-off grade of 0.50 g Au/t and below this shell at a cut-off grade of 2.0 g Au/t. Details on the mineral resource estimation procedures are given in the notes below. An updated NI 43-101 Technical Report on Hope Brook outlining the procedures for estimation of the mineral resource estimates presented herein will be filed on SEDAR within 45 days of the date of this press release.
Copper Content Assessment
In the previous estimates of mineral resources for Hope Brook copper was not interpolated due to a lack of assay data in historical drilling. New drilling and access to additional historical data for copper has improved the copper database, however the data distribution is still too dispersed to allow an accurate assessment of copper grade. In addition, much of the historical sampling was not continuous and therefore is more difficult to use for resource estimation.
To better understand the distribution of copper within the Hope Brook deposit it was decided to assess copper separately and report it as an exploration target. Coastal advises that the potential quantity and grade of the target is conceptual in nature, that there has been insufficient exploration to define a copper mineral resource, and that it is uncertain if further exploration will result in the target being delineated as a copper mineral resource.
A pessimistic scenario assumes that samples assayed for gold but not for copper have a value of 0% copper. For an optimistic scenario, the missing copper assays were ignored during the interpolation of the model, assuming that copper is present but that the previous operator did not submit the sample for copper analysis. With this scenario, the grade of the interval was estimated only from those samples with copper assay values. The copper values are reported using a 0.50 Au g/t cut-off for material within the resource constraining shell and 2.0 g/t cut-off for material below the resource constraining shell. The copper exploration target is estimated to range from a low of 19.0 million tonnes grading 0.06% copper containing 25.0 million lbs of copper to a high of 21.0 million tonnes grading 0.10% copper containing 46.0 million lbs of copper. This exploration target is separate and distinct from the NI 43-101 compliant mineral resource estimate for gold reported elsewhere in this press release.
Notes on Mineral Resource Estimation Methodology:
1. Mineral resources are estimated in conformance with the CIM Mineral Resource definitions referred to in NI 43-101 Standards of Disclosure for Mineral Projects. Pierre Desautels, P.Eng., Principal Resource Geologist, and Jay Melnyk, P.Eng., Principal Mining Engineer, both of AGP Mining Consultants and Qualified Persons under NI 43-101 who are independent of the Company, have prepared and authorized the release of the mineral resource estimates presented herein. The Coastal Gold and historical diamond drill hole databases and geological model developed by Coastal Gold were reviewed and validated by Michael Cullen, P.Geo., of Mercator Geological Services, a Qualified Person as defined under NI 43-101 who is independent of the Company. This mineral resource estimate is an update of the NI 43-101 mineral resource estimate released by the Company on October 1, 2012 (see press release October 1, 2012). 2. Specific gravities were determined by Coastal Gold for a representative number of rock and mineralization types using industry standard methods. A total of 3,650 determinations exist in the database. The average value for each modeled domain was applied to the block model. Specific gravities were further confirmed in testing of representative core samples by G&T Metallurgical Services, a division of ALS Metallurgy. 3. Detailed geological logging and sectional interpretations by Coastal Gold led to the development of three-dimensional (3D) domain models based mainly on assay results and partially on lithological controls. The wireframing resulted in a high grade envelope (approximately 2.0 g Au/t cut-off grade) within a lower grade silicic domain (between 0.5 g to 1.0 Au/t cut-off grade) that encompasses the bulk of the mineralization. These domains were utilized in the variography studies and in grade interpolation constraints. A footwall pyrite domain and a hanging wall argillic alteration domain were also wireframed to enable interpolation of local areas of mineralization. The mineralization is cut by a series of mafic dikes that could not be individually wireframed, therefore a statistically derived dike model was constructed that was calibrated with available surface and historical underground geological information. The model prepared for the October 1, 2012 resource estimate was updated based on the new 2012 and 2013 diamond drilling information. 4. For the treatment of outliers each statistical domain was evaluated separately for gold and a combination of grade capping and search restrictions imposed on threshold values was used to restrict the influence of outliers. Capping only affected a small number of samples. 5. The composite intervals selected were 2.5 metres. Grade capping was applied prior to compositing. 6. A 3D geological block model was generated using GEMSAcopyright software. The block model matrix size is 10 metres by 5 metres by 5 metres. This was a reduction in size from the previous model (15 metres by 5 metres by 10 metres) to improve selectivity of potential mining. Ordinary kriging was used for all domains with inverse distance and nearest neighbour check models. The interpolation was carried out in multiple passes with increasing search ellipsoid dimensions. Classification for all models was based primarily on the pass number followed by an adjustment to the class model, based on the distance to the closest sample and kriged variance. Confirmation of the historical stope location by 2012 and 2013 Coastal Gold drilling allowed the upgrading of most of the previous inferred blocks in the immediate area surrounding the three dimensional modelled stopes. 7. Contained copper was assessed as a target for further exploration using a range of values due to the uncertainty originating from missing assays in the historical dataset and does not form part of the mineral resource statement. 8. The reported mineral resources are considered to have reasonable prospects of economic extraction. A Lerchs Grossman optimized constraining shell was generated to constrain the potential open pit material. This shell was designed using design parameters and costs for comparable deposits, 86% recovery based on new metallurgical testing and historical plant performance and a gold price of US$1,400 per ounce, which is below the three year moving average price. The constraining shell extends down to the 4,800 metre level, the deepest level developed in the historical mine at approximately 340 metres below surface. 9. The rounding of tonnes as required by NI 43-101 reporting guidelines may result in apparent differences between tonnes, grade and contained ounces. 10. Mineral resources that are not mineral reserves do not have demonstrated economic viability. The estimate of mineral resources may be materially affected by environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues. 11. The quantity and grade of reported inferred mineral resources in this estimation are uncertain in nature and there has been insufficient exploration to define these inferred mineral resources as indicated or measured mineral resources and it is uncertain if further exploration will result in upgrading them to indicated or measured mineral resources.
SAMPLING, ASSAYING AND QUALITY CONTROL
All drill core in the Coastal Gold diamond drilling programs (NQ (47.6 mm), BQTK (40.6mm) and BQ (36.4mm)) was logged, photographed and then sawn in half with one-half sent to the laboratory for analysis and the other half retained and stored on site. All core samples were prepared and assayed at ALS Chemex, with sample preparation done in Sudbury and analytical work done in Vancouver. All locations of ALS Chemex are ISO 9001:2000 certified. The entire sample received is weighed and crushed to = 70% passing 2mm (10 mesh). A sample split of up to 1,000g is then pulverized to = 85% passing 75 microns (200 mesh) to produce a homogenized sample. A 50g aliquot is used for fire assaying with an atomic absorption (AA) finish to determine gold concentration. Copper is initially analyzed using a four acid digestion ICP (inductively coupled plasma-atomic emission spectrometry) method. Any results for copper greater than 10,000 ppm are assayed further by a four acid digestion and "ore grade" ICP method. Internal quality control includes the use of blanks, duplicates and standards in every batch of samples. The Company also conducts internal check assaying using certified external reference standards and blanks. Regular external check assays are performed at a second certified Canadian commercial laboratory. Coastal Gold also inserts external reference standards as well as blank granite drill core in each sample batch as a further external check.
QUALIFIED PERSONS
David Copeland, P.Geo., Chief Geologist, and Dr. Bill Pearson, P.Geo., President & CEO of Coastal Gold, both Qualified Persons as defined by NI 43-101, have reviewed and approved the scientific and technical content of this news release. Pierre Desautels, P.Eng., Principal Resource Geologist, and Jay Melnyk, P.Eng., Principal Mining Engineer, both of AGP Mining Consultants and Qualified Persons under NI 43-101 who are independent of the Company, have prepared and authorized the release of the mineral resource estimates presented herein. The Coastal Gold and historical diamond drill hole databases and geological model developed by Coastal Gold were reviewed and validated by Michael Cullen, P.Geo., of Mercator Geological Services, a Qualified Person as defined under NI 43-101 who is independent of the Company.
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