Tigris Releases Resource Estimates
VANCOUVER, May 29, 2012 /PRNewswire/ - Tigris Uranium Corp. (TSX.V: TU) ("the Company") is pleased to announce that it has received a resource estimate covering the Company's Crownpoint and Hosta Butte Project located in the Grants Uranium District of McKinley County, New Mexico, USA.
The "Crownpoint and Hosta Butte Uranium Project Mineral Resource Technical Report - National Instrument 43-101", dated May 14, 2012 calculates indicated mineral resources on the Project totalling 29.68 million pounds of U3O8 at an average grade of 0.104% e U3O8 and inferred mineral resources totalling 6.13 million pounds of U3O8 at an average grade of 0.110% e U3O8 as set out in further detail below.
The Company holds a 100% interest in the mineral estate (excluding hydrocarbons) in approximately 115,000 acres (46,400 ha) which encompass the Project (save for approximately 140 acres in which the Company holds a 60% interest), subject only to a 3% gross profits royalty on uranium produced, and the reported resources are located in 3,020 acres (1,22 ha) of this total. The resource estimates provided herein are being published in place of previous resource estimates for the Project, released by the Company in 2010 and retracted by the Company as a result of a continuous disclosure review by the British Columbia Securities Commission (see TU News Release 11-08).
|Million Tons(1)||Grade e U3O8 (%)||
|Crownpoint - Indicated(2)||9,477,000||0.102||19,205,000|
|Host Butte - Indicated||4,799,000||0.109||10,477,000|
|Crownpoint - Inferred(2)||743,000||0.105||1,562,000|
|Host Butte - Inferred||2,046,000||0.112||4,571,000|
(1) GT cutoff: Minimum Grade (% eU3O8) x Thickness (Feet) for Grade > 0.02
(2) Disclosed tonnage represents the Company's 100% interest in the s. 19/29 Crownpoint Property and its 60% interest in s. 24 Crownpoint Property
The resource estimate covers approximately 3,020 acres located in (A) portions of Sections 24, Township 17 North, Range 13 West (in which the Company holds a 60% interest) and (B) Sections 19 and 29, Township 17 North, Range 12 West and Sections, 3, 9, and 11, Township 16 North, Range 13 West (in which the Company holds a 100% interest), New Mexico Prime Meridian and uses Canadian Institute of Mining, Metallurgy and Petroleum definitions.
The Report is authored by Douglas L. Beahm, PEng, PGeo, President of BRS Inc., a registered member of the Society for Mining, Metallurgy and Exploration and an independent Qualified Person as defined in NI 43-101. Mr. Beahm has reviewed and approved the technical information in this news release. The Report will be filed on SEDAR (www.sedar.com) in the next 45 days.
The mineral resource estimate was completed using the GT (Grade x Thickness) Contour Method for each of individual mineralized zones of the deposit. The Contour Method, also known as the Grade x Thickness (GT) method, is a well-established approach for estimating uranium resources and has been in use since the 1950's in the US. The technique is most useful in estimating tonnage and average grade of relatively planar bodies where lateral extent of the mineralized body is much greater than its thickness, as was observed for detailed review of the data at Crownpoint and Hosta Butte.
For tabular and roll front style deposits the GT method provides a clear illustration of the distribution of the thickness and average grade of uranium mineralization. The GT method is particularly applicable to the Crownpoint and Hosta Butte deposits as it can be effective in reducing the undue influence of highgrade or thick intersections as well as the effects of widely spaced, irregularly spaced, or clustered drill holes. This method also makes it possible for the geologist to fit the contour pattern to the geologic interpretation of the deposit.
For each zone within the Crownpoint and Hosta Butte areas of the project, limits of mineralization were determined by interpretation of the drill data. Within these limits the GT and T (Grade x Thickness and Thickness) were contoured. Although an automated contouring program was used breaklines or limits were established where appropriate to constrain the estimate. For example drill holes with GT values several times the average were limited in their influence by establishing a breakline. By applying a rock density factor pounds are directly calculated from the GT contour data and tons are directly calculated from the T contour data. Grade is then calculated as GT divided by T.
The GT contour method is used as common practice for Mineral Reserve and Mineral Resource estimates for similar sandstone-hosted uranium projects ("Estimation of Mineral Resources and Mineral Reserves", adopted by CIM November 23, 2003, p 51.). It is the opinion of the author that the GT contour method, when properly constrained by geologic interpretation, provides an accurate estimation of contained pounds of uranium.
The current drill hole database consists of:
- Crownpoint Area - 482 drill holes (of which 93 did not meet minimum cutoff criteria); and
- Hosta Butte Area -135 drill holes (of which 42 did not meet minimum cutoff criteria).
The uranium quantities and grades are reported as equivalent U3O8 (eU3O8), as measured by downhole gamma logging. The industry standard protocol for reporting uranium in sandstone hosted deposits in the US has been validated for the Project.
A cutoff grade of 0.02% U3O8 and a GT of 0.10 were used as the cutoff criteria for the estimation of the total in situ mineral resource within the Project. The cutoff assumes that the mining method to be employed will be ISR as is planned for the adjacent Uranium Resources Inc. Crownpoint project.
Cutoff criteria for mining projects are determined based upon estimated metal recovery and production costs as compared to the value of the metal. No current preliminary economic assessment and/or feasibility study has been completed for the Project. Thus, calculation of project specific cutoff criteria is not possible for the Project at this time. However, the recommended cutoff criteria is supported by published production costs for the adjacent Crownpoint project of Uranium Resources Inc. Uranium Resources Inc.'s projected Crownpoint production costs are $11.46 per lb U3O8 direct and $13.46 per lb U3O8 with G&A (Pelizza and McCarn, 2004). Given that these costs should reflect the average grade of the deposit, approximately 0.10 % U3O8, the cost of recovering lower grade would be proportionately higher. At the minimum cutoff grade of 0.02% U3O8 (one-fifth of the average grade) it would be expected that the costs would be approximately 5 times greater or approximately $57 to $67 $/lb which is roughly a breakeven cost at a selling price of $65/lb.
The great majority of the geophysical logs were completed by Conoco Minerals using company owned and operated logging units. A limited number of logs were completed by Geoscience Logging, a commercial vendor, but they represent less than 5% of the total logs. Conoco operated Mount Sopris logging units which were very common in the industry at the time exploration and development was active at the Project. Mount Sopris is still active in the industry. The author worked for two separate major uranium producers in the 1970's and 80's who operated Mount Sopris equipment and is very familiar with their operation and calibration procedures. While at the site the author met with a former operator of the logging units and discussed Conoco's general procedures. The procedures included field calibration check of the equipment prior to the logging of each hole (documented on the logs); routine calibration of the units at the Grants, New Mexico facility operated by the Department of Energy and full calibration of the units at the more extensive DOE facility in Grand Junction, Colorado whenever major changes were made to the units (new probes, cabling etc.). K factors, deadtimes and water correction factors were recorded on many of the logs and on all of the internal calculation sheets.
To independently verify the historic electronic database, a sampling of the geophysical logs, including all of the core holes, was interpolated using the half amplitude method (Dodd, 1967). The results are predictable in that the half amplitude method more precisely defines the bed boundaries resulting in a lesser interpolated mineralized thickness than the computer routines. Both methods typically yield similar grade thickness (GT) and thus the half amplitude method has a slightly higher grade than the computer routine.
The results for Crownpoint are that the independent analog interpretation yielded a total GT within 3% of the computer database. When the water factor was applied, the results for Hosta Butte are that the independent analog interpretation yielded a total GT within 1% of the computer database. It is the author's conclusion that for Hosta Butte the use of the database should be adjusted for the appropriate water factor (1.12).
The author concludes that the electronic drill hole database available for the Project is reliable for the purpose of estimating mineral resources.
Historic written procedures for core handling and sample analysis were available with the core data records. In sum the cores were split through the zones of interest determined by the geophysical logs and scanning of the cores with a scintillometer. All of the samples were assayed using either a Beta Gamma Scaler or an X-ray fluorescence at the mine site. Quality control of the on-site assay equipment was provided through an independent laboratory, Hazen Research, which completed fluorometric analysis of select samples including the majority of the higher grade samples. Original assay sheets were available for 32 of the 35 cores holes.
Core samples from the Crownpoint and Hosta Butte areas were donated to the USGS Core Research Center (CRC) located at the Denver Federal Center in Lakewood, Colorado. The author visited the CRC on May 7, 2012 and reviewed the cores and selected 20 samples from core holes geographically distributed within the Project. The selected samples were assayed at Intermountain Labs (IML) in Sheridan, Wyoming, a certified laboratory.
Confirmatory assays were higher grade than the historic data. The author concludes that while the confirmatory data would support a positive adjustment in estimated grade of uranium, use of the historic core assay data is conservative, reasonable, and reliable for the purposes of estimating mineral resources for the Project.
A unit weight of 16 cubic feet per ton or 2.439 tons/m3 was assumed for all mineral resource and reserve calculations. This assumption was based on data from feasibility studies prepared by previous operators of the Project but was not independently confirmed other than to review the density data available from the core drilling. The use of 16 cubic feet per ton was recommended by the author as a typical value based on his mining experience with similar sandstone hosted uranium deposits.
The author reviewed the historic procedures followed by the previous operator of the project, Conoco Minerals, including procedures for rotary and core drilling, geophysical logging and log interpretation, and sampling and assaying. In addition, the author reviewed and verified the work product that was developed for the Project including the original geophysical and lithologic logs, sampling records, and original core assay records. It is the author's opinion that the procedures, practices, and analytical equipment utilized and/or employed on the Project were consistent with the general industry standards and practices at that time. The author further concludes that the data utilized in this report is accurate and reliable for the purposes of its use in the Report.
About Tigris Uranium Corp.
Tigris Uranium Corp. is committed to maximizing shareholder value and is well positioned with a treasury of approximately $9 million and a low annual expenditure rate. Tigris owns 115,000+ acres (46,400 ha) of private mineral rights, with an indicated resource of 29.7 MM pounds U3O8 and an inferred resource of 6.1 MM pounds U3O8 (Beahm, 2012) located in New Mexico's Crownpoint Uranium District, a portion of which is under NRC license, in a new progressive New Mexico regulatory and political environment.
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
This press release contains projections and forward-looking information that involve various risks and uncertainties regarding future events. Such forward-looking information can include without limitation statements based on current expectations involving a number of risks and uncertainties and are not guarantees of future performance. There are numerous risks and uncertainties that could cause actual results and Tigris Uranium Corp's plans and objectives to differ materially from those expressed in the forward-looking information. Actual results and future events could differ materially from those anticipated in such information. These and all subsequent written and oral forward-looking information are based on estimates and opinions of management on the dates they are made and are expressly qualified in their entirety by this notice. Except as required by law, Tigris Uranium Corp. assumes no obligation to update forward-looking information should circumstances or management's estimates or opinions change.
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