PROJECTS - Don Sixto (La Cabeza)
Drilling
Due to the success of the 2005 drilling in identifying new gold zones and extensions, an expanded + C$ 5 million program has been developed for 2006 exploration at Don Sixto. Two multi-purpose reverse circulation-diamond drills and two conventional diamond drills are currently operating at Don Sixto. A fifth drill rig, a large Schramm RC drill arrived on site late September to commence preliminary testing of an identified aquifer to provide a sustainable water supply to a mining operation of up to two million tones of ore per annum. On completion of this program, the drill will move on to Cuello, Mandibula and Ojo ones to test deeper sections of the deposits.
At the end of June, the drilling program that was commenced in January was 45 percent complete, with 6500 meters remaining. The program for the remainder of 2006 was increased to extend and add definition to new mineralization identified in the 2006 program. A total of 25,000 meters of drilling is scheduled to be completed late 2006, comprising 12,000 meters of diamond drilling, 11,000 meters of reverse circulation ("RC") drilling, and +2,000 meters of rotary air blast ("RAB") drilling. Exeter currently has five drill rigs under contract from Major Perforaciones SA, the Argentina division of Major Drilling Group International Inc. of Canada.
The following schematic geology map displays the locations of all of the RC and diamond drill holes up to April 2007 along with the names of the various prospects at the Don Sixto Gold Project.
Drill plan - all RC and diamond drill holes up to April 2007.
The proposed drilling for 2006 is divided into three categories:
- resource definition drilling within the known zones
This component of the program is aimed at increasing the confidence level of previously estimated "inferred" resources to "indicated" or "measured" resources. Work to date has concentrated at the Cuello, Luna, Ojo, Mandibula and Central Vein Zone prospects. - drilling to delineate extensions to the known vein systems
This component of the program is to delineate extensions and new parallel veins to the known vein systems. The prospects presently included in this program are Cuello North, Cuello South, Cuello West, Cuello East, Cuello Deeps, Luna Extensions, Ojo Extensions, Mandibula Extensions and the Central Vein Zone. - "discovery drilling"
Discovery drilling essentially consists of two components:- The discovery drilling program initially utilised a RAB rig, which was imported from Australia in 2005, to drill through shallow sand cover. RAB drilling has been employed very successfully as a principal exploration tool in similar conditions in Australia, where it has been responsible for several major gold discoveries including the large, high grade, Kanowna Belle, Jundee and Plutonic gold mines in Western Australia. It was much faster and less expensive than conventional core or RC drilling and permitted Exeter to drill patterns of drill holes, with which to hone in on hidden deposits at Don Sixto, much more quickly and cost-effectively than would otherwise be the case.
- The discovery drilling program now includes "fences" of RC drill holes in areas of sand cover to test prospective structural corridors. This work is currently in progress and results will be released following compilation and verification of assay results.
- The re-interpretation of existing data sets, comprising previous geophysical surveys (see Don Sixto - Geophysics), geological and structural models (see Don Sixto - Geology), and geochemistry (see Don Sixto - Geochemistry) will lead to conceptual targets that will be drill tested by RC drilling.
Resource Definition Drilling Discussion
The first portion of the drill program at Don Sixto to support the Sandercock preliminary study was completed in March 2005. The program consisted of 33 diamond drill holes totaling 2,069 meters and 44 RC holes totaling 2,729 meters. A comprehensive channel sampling program totaling 2,050 meters was also completed.
The program led to a more detailed picture of the mineralization and allowed the construction of three-dimensional geological models of the main zones and a new overall geological model for the property. New areas of higher-grade mineralization were recognized in the Ojo, Luna and Mandibula zones as well as new exploration targets. Some targets represented mineralization which may have been displaced by faulting from an existing zone, whereas other targets represent possible blind mineralization below superficial sand deposits between areas of outcrop.
The program also provided sufficient data to allow geostatistical resource estimation techniques to be trialed for Cuello, Luno and Ojo. These proved successful and enabled Resource estimates for those deposits to be calculated with sufficient confidence to meet international classification standards. This approach also helps to determine the additional drilling needed to increase confidence levels and was used to help plan the new drilling programs.
The drilling section is divided under the following headings:
- El Cuello - Discovery Drilling & Resource Drilling
- La Luna - Discovery Drilling & Resource
- El Ojo - Discovery Drilling & Resource Drilling
- La Mandibula - Discovery Drilling & Resource Drilling
- Central Vein Zone - Discovery & Resource Drilling
- Other - Cachete & Barbilla
- RAB Exploration Drilling
- Linking the Cuello and Central Vein Zones - "The Silver Connection"
- Channel Sampling Discussion
- Sampling and Assaying Procedures
Drill Cross Section
Click the links below to view cross sections:
El Ojo
La Luna
LUNA 2070N.pdf
LUNA 2000N.pdf
LUNA 2100N.pdf
LUNA 2140N.pdf
La Mandibula
El Cuello
Cuello 10175N.pdf
Cuello 10200N.pdf