RVD drills 16.73 m of 25.01% KCL at Sergipe Rio Verde Minerals Development Corp. has released the first set of assay results from its first drill hole at the Sergipe potash project, located in the Sergipe basin in northeastern Brazil. The assays refer to the sylvinite-bearing zones intercepted at the SED-001-11 drill hole at the Sergi target, which was completed in November, 2011. Samples from the drill core were shipped to Ercosplan, Rio Verde's independent engineering consultant, and analyzed at Ercosplan's independent partner lab based in Germany.
The sylvinite assay results showed evaporites characterized by high potash content and low anhydrite content distributed in two significant sylvinite-bearing zones with a weighted average grade of 25.01 per cent potassium chloride (KCl) over 16.73 metres. Starting at 1,189.38 metres depth, the upper zone returned an 8.27-metre composite interception averaging 20.94 per cent KCl, including 5.08 metres at 24.84 per cent KCI, and 1.29 metres at 36.26 per cent KCI. The lower zone, which starts at 1,221.86 metres depth, intercepted 8.46 metres at 28.98 per cent, including 5.47 metres at 39.65 per cent KCI.
A summary of the sylvinite assay results is provided in the associated table.
DRILL RESULTSCategory From (m) To (m) Interval (m) Grade (KCl)Sylvinite zone 1 1,189.38 1,197.65 8.27 20.94including 1,189.38 1,190.67 1.29 36.26 1,192.57 1,197.65 5.08 24.84Sylvinite zone 2 1,221.86 1,230.32 8.46 28.98including 1,221.86 1,227.33 5.47 39.65 1,227.33 1,230.32 2.99 9.47
Analysis of the downhole geophysical logs has been concluded. The information derived from this analysis has been used to refine the location of the next drill hole at the Sergi target, SED-002-12, to be located 2.69 kilometres west-southwest of SED-001-11. In addition, the bore hole temperature, an important factor in determining conditions for an envisioned solution mining and recovery process, was estimated at 57 C.
"With the receipt of these assay results, we can confidently say that Rio Verde has confirmed the historical observation of potash on its properties, our primary objective for drilling this first hole," said Rio Verde chief executive officer Stephen Keith. "The excellent grades and potash thicknesses intersected represent an important step in the development of Rio Verde's Sergipe potash project. We are also pleased with the results from the downhole geophysical interpretation; it has indicated favourable downhole temperature and data, which has allowed us to improve our seismic data interpretation and increase our confidence in the placement of our second drill hole. The relocation of the next drill platform has required us to apply for a new drilling permit, which we anticipate will be granted in the next few days, with rig mobilization to start immediately thereafter."
Carnallitite assays
As reported in Rio Verde's Nov. 16, 2011, press release, drill hole SED-01-011 also intercepted a significant carnallitite horizon of 61 metres at a vertical depth starting at approximately 1,235.74 metres. These horizons contain significant high-grade carnallitite mineralization, especially in the middle and the lowermost horizons. As this intercept was much larger than anticipated, the volume of samples sent to the laboratory was also significantly larger than anticipated. Ercosplan thus requires additional time to process the carnallitite assay results. The core samples of this carnallitite-bearing zone are presently being assayed by Ercosplan, with results expected later this month.
Qualified person
The qualified person, as such term is defined in National Instrument 43-101, who has reviewed and approved the technical information in this new release, is Dr. Henry Rauche of Ercosplan of Erfurt, Germany, an independent consultant for Rio Verde.
About the Sergipe potash project
The Sergipe potash project is located in the development-friendly state of Sergipe, in an area with established infrastructure, adjacent to Brazil's only producing potash mine, Vale's Taquari-Vassouras mine. Rio Verde's Sergipe project comprises 11 separate landholdings over a total area of approximately 106,336 hectares. These landholdings have been grouped into nine onshore and two offshore prospects, with the main prospects being the Sergi prospect, the Rio do Sal prospect and the Capela 1 prospect. Rio Verde has identified seven potash drill-ready targets, which were selected following an extensive remodelling of the geology of the Sergipe basin, based on approximately 234 line kilometres of 2-D seismic data, and the acquisition of geological data from 286 historic oil wells in the area. Rio Verde's drilling program is targeting sylvinite horizons at its Sergi prospect, as well as significant potential caranallite horizons.
As part of the company's continuing strategic land evaluation, Rio Verde continues to analyze its key potash targets in order to plan future exploration. Taking into consideration extensive historic information and recent seismic interpretation, Rio Verde decided to end its option agreement with Lara Alliance (BVI) Ltd., and has returned control of the project properties under agreement to their original owner. The project properties were not in line with Rio Verde's immediate exploration goals and were not considered to be a material portion of the company's assets.