TriStar Announces Resource Estimate for Castelo De Sonhos Gold Paleo-Placer Project
September 18, 2017
SCOTTSDALE, AZ--(Marketwired - September 18, 2017) - TriStar Gold Inc. (the "Company" or "TriStar") (
- Inferred mineral resource (0.4 g/t cut-off) of
- 31 million tonnes,
- at 1.3 g/t,
- containing 1.3 million ounces of gold
- Results validate the exploration target range projections that have been utilized to guide drill targets
- Approximately 30% of the assays from the current RC program are still pending for inclusion in an updated resource estimate
- Substantial amounts of Esperança Central and South still untested
- Esperança East and West will be drill tested in 2018
- Preliminary economic assessment to be based on updated resource
"We are very pleased to see the predictions of the exploration target range now being validated by hard data. This resource uses all the available data on the project, however 30% of the assays from the now completed RC program are still outstanding and we have not yet started to test Esperança West or East," says Nick Appleyard, TriStar's President and CEO. "We are looking forward to updating the resource soon and completing the technical and economic studies that will support the preliminary economic assessment."
Table 1. Mineral resource estimate1 for the Castelo de Sonhos gold project (with an effective date of September 13, 2017) above a reporting cutoff2 of 0.4 g/t Au.
|1Numbers have been rounded to reflect the precision of an Inferred mineral resource estimate.
2The reporting cutoff corresponds to the approximate marginal cutoff for an open pit with total operating cost (non-waste mining + processing + G&A) of $US 15.00/t, metallurgical recovery of 98% and a gold price of $US 1,200/oz. These are mineral resources and not reserves and as such do not have demonstrated economic viability.
3The metal content estimates reflect gold in situ, and do not include factors such as external dilution, mining losses and process recovery losses.
4TriStar is not aware of any environmental, permitting, legal, title, taxation, socio-economic, marketing or political factors that might materially affect these mineral resource estimates.
As shown in Figure 1, the new resource estimate extends the footprint of the previous resource estimate considerably further to the southwest, and to the north. The new RC drilling also allows the resource block model to extend to 120m below surface, approximately 50m deeper than the previous block model. With the assays available by August 2017, resources were not estimated in gaps in Esperança South and Center where drill hole spacing exceeds 100m; and resources have not yet been estimated in Esperança East and West, where drilling is planned for 2018.
Resource estimation method
All available drill hole data was used, including the results from holes RC17-197 through RC17-249 that have not been published, but results are generally in line with previously disclosed drill results.
The resource is constrained by a mineralized envelope that corresponds to the conglomeratic band of the paleo-placer, honouring its outcrop location and surface measurements of its bedding orientations, and extending into the upper arenite where drilling has confirmed that the base of the upper arenite contains remobilized gold. All drill hole assays were capped at 20 g/t.
Sample intervals were assigned one of three lithologies: pebble-supported conglomerate, matrix-supported conglomerate or "other". Ordinary kriging was used to estimate the proportion of each lithology within 30´30´6m panels; local uniform conditioning was used to estimate, for each lithology, the gold grade distributions of 5´5´2m selective mining units (SMUs) within each panel. The 5´5´2m SMU distribution of gold in each panel was a tonnage-weighted average of the distributions for each lithology. For each panel, the bedding direction was estimated from available surface measurements; ranges of correlation and search radiuses were set to 100m parallel to bedding, and 20m in Center and 30m in South perpendicular to bedding. Search strategy parameters were adjusted so that global grade-tonnage curves matched well to the results obtained from a change-of-support analysis of the distribution of composite gold grades in each area, Esperança South and Esperança Center, using a 5x5x2m block as the selective mining unit. This use of a target reference distribution from a global change-of-support analysis ensures that the estimates have the correct level of variability. The uniform conditioning block model was checked using a different grade estimation method, inverse-distance interpolation; the results of the two models are within ±10% of each other for the totals reported in Table 1.
All resources to a depth of 120m below the ground surface, inside the conglomerate band, and inside the green region shown in Figure 1 were classified as Inferred; no resources were classified as Measured or Indicated. Current open pit operations in similar paleo-placer projects such as the Tarkwa mine of Gold Fields show that resources down to 120m below surface have reasonable prospects for eventual economic extraction.
The resources classified as Indicated in 2014 have been reclassified as Inferred, pending implementation of CSA's recommendation for collection of a suite of samples for determination of dry bulk density.
Resource Sensitivity Table
Table 2. Mineral resource estimate sensitivity to cut-off for the Castelo de Sonhos gold project.
Adrian Martinez (P.Geo.) of CSA Global is the independent Qualified Person for the mineral resource estimates presented in this press release, has approved its publication, and will be the principal QP for the National Instrument 43-101 technical report that will be filed on SEDAR within 45 days.
TriStar Gold is an exploration and development company focused on precious metals properties in the Americas that have potential to become significant producing mines. The Company's current flagship property is Castelo de Sonhos in Pará State, Brazil. The Company's shares are listed on the TSX Venture Exchange under the symbol TSG. Further information is available at www.tristargold.com.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.
Certain statements contained in this press release may constitute forward-looking statements under Canadian securities legislation which are not historical facts and are made pursuant to the "safe harbour" provisions under the United States Private Securities Litigation Reform Act of 1995. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "expects" or "it is expected", or variations of such words and phrases or statements that certain actions, events or results "will" occur. Forward looking statements in this press release include, the scope and success of the planned exploration program at the Castelo de Sonhos project and the Company's opinion that it has clear title to the Castelo de Sonhos property Such forward-looking statements are based upon the Company's reasonable expectations and business plan at the date hereof, which are subject to change depending on economic, political and competitive circumstances and contingencies. Readers are cautioned that such forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause a change in such assumptions and the actual outcomes and estimates to be materially different from those estimated or anticipated future results, achievements or position expressed or implied by those forward-looking statements. Risks, uncertainties and other factors that could cause the Company's plans to change include changes in demand for and price of gold and other commodities (such as fuel and electricity) and currencies; changes or disruptions in the securities markets; legislative, political or economic developments in Brazil; the need to obtain permits and comply with laws and regulations and other regulatory requirements; the possibility that actual results of work may differ from projections/expectations or may not realize the perceived potential of the Company's projects; risks of accidents, equipment breakdowns and labour disputes or other unanticipated difficulties or interruptions; the possibility of cost overruns or unanticipated expenses in development programs; operating or technical difficulties in connection with exploration, mining or development activities; the speculative nature of gold exploration and development, including the risks of diminishing quantities of grades of reserves and resources; and the risks involved in the exploration, development and mining business. Although management of the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements or forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. The Company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise, except as required by applicable securities laws.
For further information, please contact:
TriStar Gold Inc.
President and CEO