May 29 2017
TriStar Gold Inc. is pleased to provide an update on the drilling at Castelo de Sonhos. To date, 18 reverse circulation (RC) holes have been completed for 2,090 m.
These drill holes include three twin redrills of core holes, with the remainder being 100 x100m in-fill drilling on the southwestern limb to add to Inferred resources for the upcoming preliminary economic assessment (PEA). Nick Appleyard, TriStar's President and CEO commented: "The quality of samples and field data that we are collecting is excellent. The optical televiewer images have surprised all of us with their clarity, allowing for a level of detailed logging better than we could have achieved with drill core."
The field trial of the optical televiewer (OTV) and petrophysical downhole logging has been completed and 20 holes have been logged (this includes 12 core holes and 8 RC holes). Although all the data have not yet been fully analyzed, the results are very promising. The OTV has been returning superb images from inside the RC holes; this allows for accurate logging and measurement of all downhole features, as can be seen from Fig. 1. The field trial also confirms that the magnetic susceptibility log does correlate with heavy mineral layers, and, in places, also with gold grade; this is likely a reflection of the association of different types of heavy particles in a paleo-placer environment. If this association persists over large regions, magnetic susceptibility may have a beneficial role not only in making resource and reserve estimates more reliable, but also in improving grade control.
Samples have been shipped to Parauapebas, Pará State, where pulp material is prepared and shipped to Belo Horizonte, Minas Gerais, for analysis. Both facilities are run by SGS Geosol, an ISO 9001:2008 and 14001:2004 certified laboratory which employs industry-standard methods for sample preparation and analysis. As part of TriStar´s QA/QC protocol, standard, blanks and field duplicates were inserted into the sample processing stream at a rate of one per 10 samples. Internal laboratory duplicate and replicate samples also form part of the QA/QC protocol. Once the analysis of the twin holes and the QA/QC program are complete, likely in June, TriStar plans to publish drill results and to update this information on a monthly basis as drilling continues through the summer.
TriStar had completed arrangements for two additional RC rigs to begin drilling this month. One will initially target the southwestern limb with 50x50m drilling aimed at augmenting Indicated resources in this area. The other will target the northern end of Esperança Center with infill holes.
TriStar's Vice-President, R. Mohan Srivastava (P.Geo.), is the QP for this press release and has prepared or supervised the preparation of the scientific or technical information in this press release.