Silver Dragon Resources Inc. (OTCBB:SDRG) has announced that it has completed an initial geological report from recently completed exploration work at the Company's Laopandao Silver-Tin-Copper-Lead Polymetallic project in Inner Mongolia, Northern China.
Since 2006, an advanced drilling program has been carried out on the project, focusing on three mineralization zones and it is these three zones which were the focus of the report.
Highlights
- Mineralization zone I is featured by a silver-copper-tin enrichment and is approximately 540m long, 100m wide with a dip extension of over 300m, containing 8 mineralized bodies with average grades Ag 231.7 g/t, Cu 0.48%, and Sn 0.335%.
- Mineralization zone II is also featured by a silver-copper-tin enrichment and is approximately 200m long and 80m wide, containing 16 mineralized bodies with the highest average grade of individual mineralized body at Ag 274.46 g/t, Cu 1.26 % (II-3 mineralized body), and Sn 0.185% (II-1a mineralized body) .
- Mineralization zone III is characterized by tin mineralization, approximately 300m long and 200m wide and occurs within a granite porphyry intrusion. A total of 21 mineralized bodies were identified with the highest Tin ore grade at 34.08% and average Tin grade of 0.413%.
- All mineralized bodies have been defined by drill holes and/or underground drifts, the samples were analyzed with internal and external verification.
- The initial resource estimate of the three mineralization zones are based on Chinese National Non-ferrous Metal Resource Estimation Standards. Estimates show 4,616,370 t (metric tonnes) of ore with 318.2 t (10.2 million oz.) silver, 10,239 t copper, and 15,184.5 t tin.
- The Company will continue advanced exploration of Laopandao in 2011. The company will conduct metallurgical testing on the 2010 exploration results and commission an initial NI 43-101 technical report based on CIM standards.
1. General geology and main exploration targets of the Laopandao Property
Laopandao, a key exploration project for Silver Dragon, is located in Inner Mongolia Keshiketeng County, North China and is 44.88 km2.
The exposed rocks in the exploration area include Paleozoic Middle Permian Zhesi Formation andesite, Mesozoic Upper Jurassic Baiyigaolao Formation volcanic series, and Yanshanian granite porphyry and quartz porphyry intrusions.
Based on geochemical and geophysical survey results, three geochemical anomalies were found and called anomaly No. 104 in the north, No. 95 in the central, and No. 102 in the south of the property respectively. Since 2006, most drilling and tunneling exploration work has been carried out and focused on the area of geochemical anomaly no. 95 and the three significant Silver-Copper-Tin mineralization zones, each of which consists of multiple mineralized bodies.
2. Exploration work
Based on annual exploration reports provided by the Comprehensive Exploration Institute of North China Nonferrous Geological Survey Bureau, the exploration work at the Laopandao Property is summarized as follows:
From 2006 to 2009, general and advanced geological exploration, geochemical and geophysical surveys have been carried out by the Comprehensive Geological Exploration Institute of North China Nonferrous Geological Survey Bureau. A total of 23 drill holes (9,936m) and 1,880m tunneling exploration were completed within the central area of the Property (geophysical anomaly no. 95). The exploration focused on mineralization zone I and II
In 2010, advanced geological exploration work was continued and the exploration targets were focused on mineralization zones I and III. The exploration consisted of 11 drill holes (4,696 m), 634m tunneling, and an additional geophysical survey.
3. Mineralization zones
The mineralization zones at Laopandao consist of two major types:
(1) Ag-Cu-Sn mineralization zones
Silver-Copper-Tin mineralization zones occur within Mesozoic Baiyigaolao Formation volcanic series and the mineralized bodies are lenticular or veins. Drill holes and tunnels have defined two mineralization zones.
Mineralization zone I is approximately 540m long; 100m wide, with a 250-300m down dip extension and consists of seven significant Ag-Cu-Sn mineralized bodies (I-1, I-2, I-3, I-4, I-5, I-6, I-7) and one Sn mineralized body (I-8).
The average grades of mineralization zone I are Ag 231.7 g/t, Cu 0.48%, and Sn 0.335%.
Mineralized bodies I-1 -I-7 are comprised of Silver-Copper-Tin mineralization, the mineralized bodies are light yellow to black and of lenticular shape. The metal mineral composition of ores consists of macarsite, arsenopyrite, chalcopyrite, chalcocite, tetrahedrite, pyrrhotite, cassiterite, argentite, sphalerite, and native silver. Gangue minerals are K-feldspar, quartz, sericite, calcite, and small amount of tourmaline. Commonly, the ores form disseminated structures. Alteration surrounding the mineralized bodies includes silicification, tourmalinization, sericitization, potash alteration and weak fluoritization. Mineralized body I-8 is of significant Tin mineralization with average grades Ag 51.47 g/t, Cu 0.22%, and Sn 1.35%.
Mineralization zone II is located in the south of zone I and is 250m long and 80m wide, and consists of 16 mineralized bodies.
Mineralized body II-1(a), II-14 and II-15 are more significant.
The highest average grades of any individual mineralized body are silver 274.46 g/t, copper 1.26 % (II-3 mineralized body), and Tin 0.185% (II-1a mineralized body). Mineralization and alteration styles of mineralization zone II are the same as mineralization Zone I.
(2) Tin mineralization occurring in Yanshanian granitic porphyry intrusion
Mineralization zone III is located in the southwest of the mineralization zone II and occurs within a granitic porphyry intrusion.
The inferred length of the mineralization zone III is 300m and the width reaches 200m. Based on surface trenching (TC3001-TC3005), tunneling (634m long) and 15 drill holes, a total of 21 Tin mineralized bodies were identified.
In general, mineralized bodies are 100m --250m long with a thickness from 0.8m to 14.1m. The highest Sn grade is 34.08% and average Sn grade is 0.413%.
Among them, the most significant mineralized body is III-19, distributing from exploration line 301 to 304 and defined by 15 drill holes. It is 250m long, average true thickness is 3.0m, down dip extension reached over 550m, occurring elevation is from 1,715m to 1,165m, and the average Sn grade is 0.47%. The Sn resources of mineralized body III-19 occupies 35% of the total Sn resources defined in mineralization zone III.
Alteration related to Tin mineralization includes turmalinization, silicification, sericitization, potash alteration, as well as weak fluoritization. Common sulfides are arsenopyrite and disseminated chalcopyrite.
4. Quality control of sampling, assaying and data verification
For drill cores, the sampling method consists of dividing the core along the middle line into two parts; one part for assaying and the other for storage. The sample lengths are from 1 m to 1.5m and the minimum sample length is 0.4m. Closing samples are taken from each mineralized body at the hanging wall and footwall to ensure that the mineralized body is closed by sampling.
Within underground drifts, the sampling method is channel sampling which is cut to 10cm wide and 3cm deep on the drift wall. The sample length is from 0.4m to 1.5m. Samples are collected to close the mineralized body at the hanging wall and footwall.
Collected samples are analyzed in the Yanjiao Central Laboratory of North China Nonferrous Geological Survey Bureau. From 2006 to 2009, 3,435 samples were analyzed, among which 126 samples were subject to internal assay verification and 61 samples were subject to external assay verification. In 2010, 1,000 samples were analyzed, among which 85 samples were subject to internal assay verification at the Central Laboratory and 53 samples were sent to ALS Laboratory Group, Mineral Division – ALS Chemex in Guangzhou (www.alschemex.com) for external assay verification.
The results of both the internal and external verification show that the original assay results are of high quality and accuracy.
5. Initial resource estimation
Based on available data, the initial resource estimation of silver, copper and tin have been carried out according to Chinese National Non-ferrous Metal Resource Estimation Standards.
In 2008, 16 ore samples were analyzed for volumetric weight of ore with the average value being 2.8g/m3.
Other parameters, calculation processes, and category of resources used in the resource estimation are based on Chinese National Non-ferrous Metal Resource Estimation Standards.
The results of resource estimation are as follows:
Mineralization zone I (332+333+334):
574,575t ore, containing silver 236.2t , copper 4,417.1 t, and tin 2,205.2t;
Mineralization zone II (332+333+334):
1,370,995t ore, containing silver 82.1t, copper 5,822.3t, and tin 1,552.4t;
Mineralization zone III (332+333):
2,670,840t ore, containing tin 11,426.9t.
Total resources for three mineralization zones (332+333+334) are 4,616,370t ore, containing silver 318.2t (10.2 million oz.), copper 10,239.3t and tin 15,184.5t.
According to the above initial resource estimation results, it is clear that the exploration achievements at the Laopandao property are significant with an obvious further silver-copper –tin resources and/or reserve potential.
5. Further exploration and development plan
Further exploration at the Laopandao Property is as follows:
- Tunneling will focus on mineralization zone III, in order to further define mineralized bodies.
- At mineralization zone 1 and II, more drifts will be added.
- Metallurgical testing will be conducted.
- A feasibility study on all mineralization zones will be carried out to provide basic information for further development of the Laopandao Property.
- The exploration database of Laopandao to date will be used to complete an initial NI43-101 technical report.
Assessment is preliminary in nature that it includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the preliminary assessment will be realized. The Securities and Exchange Commission does not recognize or accept NI 43-101 or Chinese estimate reporting standards. The reader is advised to perform the necessary due diligence and not make decisions solely based on the information in this press release.
Source: Silver Dragon Resources Inc.