The Las Chispas property is located approximately 180 kilometres northeast of Hermosillo, Sonora, Mexico. The community of Arizpe (estimated population 2,000) is located approximately 11 kilometres to the north of the property. The property consists of 21 concessions totalling 1377.50 hectares.
In 1640, rich silver veins where discovered near Arizpe by soldiers under the command of Pedro de Perra. The property did not receive any notable exploration or production until the late 1800s. From 1880 to 1930, several mines on the property had intermittent production. From public information, approximately 100 million ounces of silver and 200,000 ounces of gold were cumulatively produced from the property. Since 1930, no significant work has been completed on the property.
During the early 1980s, a local Mexican company reprocessed old waste and tailings dumps from Las Chispas. Processing was by vat leaching with no production records available.
Geologically, the Las Chispas property consists of a Late Cretaceous – Early Tertiary low sulfidation epithermal system. Host rocks are volcanic tuffs, rhyolites, agglomerates and rhyolite breccias. Andesite dykes are noted in underground workings sub-parallel to mineralized structures.
The Las Chispas Mine is known for its world-class silver mineral specimens including polybasite, stephanite, native silver and pyrargyrite. Specimens are on display in private collections and museums worldwide.
Mineralization occurs in 0.5 to 5 metre wide veins with adjacent stockwork and breccias trending northwest- southeast for 1 to 1.5 kilometres. Depth from surface of known mineralization is estimated at 300 metres. Main veins dip 55 to 85 degrees to the southwest. Fourteen epithermal veins have been previously defined on the property of which 3 have had notable production. The historical producing veins included Las Chispas, William Tell, and Babicanora. From public information, the Las Chispas mill production between 1908 through 1911 was approximately 25,000 tonnes grading 35 gpt gold and 4,500 gpt silver totalling an estimated 25,000 ounces of gold and 3.2 million ounces of silver. Several kilometres of underground workings exist on the property and are partially accessible.
Current Work Program
Phase II Exploration Program Outlook
The Company is preparing an underground core drilling program of 2,000 metres and a minimum surface core drill program of 6,000 metres. Phase II will commence in November 2016 and will test potential near-surface resource areas, as well as extensional targets along trend and below the historic workings.
Underground drilling is planned to start at Babicanora with approximately 5 to 10 core holes to initially test the historic mine area and multiple parallel veins. Drill access to the historic mine is provided by a 4 metre by 4 metre portal and a 230 metre drift which intersects the Babicanora Vein. Subsequent Phase II surface drilling is planned for Babicanora to initially evaluate its estimated 2.5 kilometre strike length with multiple parallel veins, stockwork and breccias (Figure 1). As with the Las Chispas and William Tell veins, Babicanora has not been previously drilled.
Additional surface and underground drilling will be conducted at the Las Chispas and William Tell veins where the Company recently completed the successful Phase I program. The focus will be on infill drilling for resource estimation and step out drilling to test the possible southern and northern vein extensions of the Las Chispas and William Tell veins.
Phase II drilling will also include initial drilling of other targets on the Company's concessions including the historic Varela Mine, Espiritu Santo Mine, and Granaditas Mine (Figure 1). The Company anticipates that this Phase II campaign will be completed by early Q2 2017, with the results to be incorporated into a maiden resource estimate for the Las Chispas project in late Q2 2017.
As previously reported, the underground drill program will also focus on the delineation of a large bulk sample. A bulk sample is a large sample, in many cases hundreds or thousands of tonnes, and is generally a composite of material from development drifts and raises. It is also used to define metallurgical characteristics. With continued success, the Company expects to begin with its bulk sample in late 2017. Arrangements for processing the bulk sample off site are required.
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Summary of Phase I Exploration Program
SilverCrest’s recently completed Phase I exploration work consisted of approximately 6,400 metres of drilling in 22 core holes. Details of the Phase I drilling results were previously announced on the Company’s news releases dated August 2, September 7 and September 14, 2016. In summary, 19 core holes have been drilled in the Las Chispas and William Tell veins. All drill holes intercepted quartz stockwork veinlets, veining and/or breccia. The drilling has defined several discoveries and confirmed high grade continuity with resultant multiple drill intercepts of greater than 2,000 grams per tonne (“gpt”) silver equivalent (“AgEq”, based on 75:1 Ag:Au and 100% metallurgical recovery). The remaining 3 holes, of the 22 drilled, targeted the La Victoria area which is approximately one kilometre southwest of the historic Babicanora Mine. The Las Chispas discoveries may be influenced by a controlling, cross-cutting, high-grade structural corridor that extends from the Las Chispas Vein through the William Tell Vein and southwest beyond Babicanora. This corridor is potentially 750 metres wide (Figure 1), and high grade mineralization appears to extend to a depth of at least 300 metres from the surface.
Some of the more significant core drilling results for the Las Chispas Vein include 4.6 metres in true width of 4.56 gpt gold and 621.5 gpt silver, or 963 gpt AgEq, including 0.8 metres grading 18.55 gpt gold and 2,460.0 gpt silver, or 3,851 gpt AgEq in hole LC16-05. Drill hole LC16-08 showed 7.2 metres in true width grading 2.41 gpt gold and 311.5 gpt silver, or 492 gpt AgEq, and a more recently announced drill assay from hole LC16-18 drilled 1.0 metre grading 1.55 gpt gold and 706.0 gpt silver, or 822 gpt AgEq (Figure 2).
The William Tell Vein runs parallel to the Las Chispas Vein and is about 120 metres to the west. The Company discovered what appears to be an unmined faulted southern extension of the William Tell Vein. Four of seven drill holes at William Tell intersected high-grade mineralization. The most notable core drilling results are 2.3 metres in true width grading 1.63 gpt gold and 583.6 gpt silver, or 705 gpt AgEq, including 0.8 metre of 3.81 gpt gold and 1,102.0 gpt silver, or 1,388 gpt AgEq in hole LC16-03 (Figure 3). Hole LC16-03 has been reinterpreted, and true thickness has been changed from 1.5 metres, as previously announced on September 7, 2016, to 2.3 metres. Drill hole LC16-15 showed 1.3 metres in true width grading 1.94 gpt gold and 352.0 gpt silver, or 494 gpt AgEq.
Two new vein discoveries were made with drill holes LC16-13 and LC16-16 near the William Tell vein. Reported grades of these new veins were 4.79 gpt gold and 364.0 gpt silver, or 723 gpt AgEq and 6.57 gpt gold and 395.0 gpt silver, or 888 gpt AgEq over estimated true widths of 0.8 metres and 0.9 metres, respectively.
Of the 14 historically identified veins near the Las Chispas and William Tell veins, 12 have been located by the Company. In the Babicanora area, five historically identified veins plus two additional veins have been located by the Company (see Figure 1).
Underground Rehabilitation Update
The Company has accessed approximately 7 kilometres of underground workings to date, with an additional 4.5 kilometres to be opened and explored over the next several months. As SilverCrest opens and explores the underground workings, the Company continues to systemically collect samples at intervals of two to three metres along strike length of veins. The Company collected a total of 318 samples at the Varela veins from 450 metres of underground access (see figure below) and (photo) as reported (here) This table summarizes the 17 most significant un-composited assay results (uncut, undiluted) greater than 500 gpt AgEq from the four levels at the El Sheik historic workings of the Varela Main Vein only; Of the 318 samples tested, 129 were vein samples and used for assay composites. The remaining samples were of hangingwall and footwall material. Sampling locations and widths are restricted to historic workings, which may only represent part of the mineralized vein, stockwork or breccia. The Company plans to complete drilling at the Varela veins to determine the location, true thickness and extent of mineralization.
The composited sample results (uncut, undiluted) for this release for four underground levels are;
- Level 1: average 0.53 metres wide grading 2.96 gpt gold and 47.0 gpt silver, or 330 gpt AgEq over a continuous 6.5 metre strike length.
- Level 2: average 0.69 metres wide grading 1.22 gpt gold and 114.1 gpt silver, or 205 gpt AgEq over a continuous 10 metre strike length.
- Level 3: average 0.88 metres wide grading 4.76 gpt gold and 147.6 gpt silver, or 504 gpt AgEq over a continuous 10 metre strike length.
- Level 4: average 1.1 metres wide grading 3.13 gpt gold and 223.6 gpt silver, or 458 gpt AgEq over a continuous 80 metre strike length excluding 7 metres of faulting.
There appears to be an increase in vein width and grade from the near surface Level 1 (1,160 metre elevation) to the deeper Level 4 (1,130 metre elevation).
The Varela veins are a low to intermediate sulphidation epithermal system immediately adjacent and near parallel to the Las Chispas and William Tell veins. The Varela veins consist of mineralized veining, stockwork or breccia. Similar to the Las Chispas Vein, the Varela veins are exposed at surface with numerous historic underground workings.
The Company intends to continue with the underground rehabilitation program on the property and reporting results for at least the remainder of 2016.
Click HERE to view the table which summarizes the most significant drill assay results (uncut, undiluted) for the Las Chispas Project
Please Click Here to view summaries of significant results of collected samples. To date, approximately 7 kilometres of underground workings have been accessed with an additional 7.4 kilometres to be explored over the next several months.
N. Eric Fier, CPG, P.Eng., President and Chief Executive Officer of the Company, is the Qualified Person under National Instrument 43-101, Standards of Disclosure for Mineral Projects, responsible for the preparation of the technical information included in this website and for supervision of field activities related to the Company projects.
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