TriStar Gold Inc. announced the start of a 2,500m expansion and exploration drilling program at its Castelo de Sonhos gold project. This core drilling is principally designed to test areas of higher-grade extensions to the Esperança South mineralization and has been developed by GoldSpot Technologies and TriStar's geological team. Drill holes have been located to test for the locations, or extensions of, gold-bearing channels. A high priority has been given to machine learning assisted proposed holes, derived from the integrated examination of mineralization and gold-hosting stratigraphy.

Factors that have been taken into consideration include: Gold is dominantly within the quartz-conglomerate unit (or nearby/adjacent, in the hanging wall or footwall); Paleochannels are traced by local variance in 3D stratigraphy derived from machine learning geochemical analysis (chemostratigraphic modelling); Target soil anomalies within buffer of outcropping quartz-conglomerate unit are especially attractive -they represent historic drilling successes; Areas with unexplained gold soil anomalies, down slope from outcropping quartz conglomerate, suggest gold bearing units in drainage at higher altitude.