Kuriskova Uranium Project, Slovakia
The Kuriskova Uranium Project is an advanced-stage uranium exploration property, with established uranium resources, located in Eastern Slovakia and controlled by Tournigan Energy Ltd (Tournigan). The Kuriskova uranium deposit is best described as an epigenetic vein-type uranium deposit, although it may have had precursor supergene and/or hypogene origins.
Potentially, the Project is an underground-mineable deposit that consists of a tabular Main Zone uranium deposit that is vein-like in shape, and an adjacent stockwork zone of mineralization. The Main Zone has moderate-to-steep dips, at an average thickness of 2 to 8 meters, strike and dip extents of several hundred meters, and average grades ranging from 0.1% U3O8 to over 0.5% U3O8. The Main Zone accounts for 68% of the total pounds of uranium contained in the deposit. All mineralized zones, combined, represent an Inferred resource of 3.78 million tonnes at a grade of 0.215% U3O8 (17.9 million pounds of U3O8), and an indicated resource of 1.19 million tonnes at a grade of 0.558% U3O8 (14.6 million pounds of U3O8); with an Inferred 3.2 million pounds Mo as a potential by-product.
SRK provided an initial resource estimate based on historical drilling and Tournigan’s drilling of Kuriskova in 2006 and 2007; and prepared a NI 43-101 Technical Report for the client. SRK estimated the resource in close association with Tournigan’s technical staff based in Slovakia and Tournigan’s database and resource manager. SRK followed-up with a review and audit of Tournigan’s update of its in-house resource model based on 2008 drilling.
During this process SRK provided Tournigan with uranium geology and resource modeling expertise that added value to the understanding of the deposit. As with many historical uranium projects, the database, by necessity, is a mix of both gamma eU% and assay U% data. A comparative analysis of gamma-only grades with XRF-determined grades was necessary to validate the use of historical data. SRK examined the relationship of gamma to assay data before including the eU% data in the resource estimation. This cannot be done on a hole-to-hole basis, as there are no true twin holes. An interval-to-interval comparison of U% and eU% is only available for recent drillholes with both analyses, and even this comparison is problematic because the from-to intervals are often different but, more importantly, the geometric (volume) support of the samples differ considerably.
For Kuriskova, the best method of comparison was to examine the grade distributions of each data set within the Main Zone wireframes, where the bulk of the total resource is located. The gamma data at 0.5m composites, from within the gamma wireframe for the Main Zone, were compared in a cumulative frequency plot with the assay data as 0.5m composites, from within the assay wireframe for the Main Zone. The grade distribution plots are nearly identical, providing confidence that the historical gamma-only data accurately represents the deposit grades. This type of analysis is just one of many concerns in dealing with uranium resource estimation with historical project databases.
By providing uranium expertise, SRK has helped Tournigan better understand the Kuriskova deposit, and added value in the process.
Allan Moran: amoran@srk.com
Potentially, the Project is an underground-mineable deposit that consists of a tabular Main Zone uranium deposit that is vein-like in shape, and an adjacent stockwork zone of mineralization. The Main Zone has moderate-to-steep dips, at an average thickness of 2 to 8 meters, strike and dip extents of several hundred meters, and average grades ranging from 0.1% U3O8 to over 0.5% U3O8. The Main Zone accounts for 68% of the total pounds of uranium contained in the deposit. All mineralized zones, combined, represent an Inferred resource of 3.78 million tonnes at a grade of 0.215% U3O8 (17.9 million pounds of U3O8), and an indicated resource of 1.19 million tonnes at a grade of 0.558% U3O8 (14.6 million pounds of U3O8); with an Inferred 3.2 million pounds Mo as a potential by-product.
SRK provided an initial resource estimate based on historical drilling and Tournigan’s drilling of Kuriskova in 2006 and 2007; and prepared a NI 43-101 Technical Report for the client. SRK estimated the resource in close association with Tournigan’s technical staff based in Slovakia and Tournigan’s database and resource manager. SRK followed-up with a review and audit of Tournigan’s update of its in-house resource model based on 2008 drilling.
During this process SRK provided Tournigan with uranium geology and resource modeling expertise that added value to the understanding of the deposit. As with many historical uranium projects, the database, by necessity, is a mix of both gamma eU% and assay U% data. A comparative analysis of gamma-only grades with XRF-determined grades was necessary to validate the use of historical data. SRK examined the relationship of gamma to assay data before including the eU% data in the resource estimation. This cannot be done on a hole-to-hole basis, as there are no true twin holes. An interval-to-interval comparison of U% and eU% is only available for recent drillholes with both analyses, and even this comparison is problematic because the from-to intervals are often different but, more importantly, the geometric (volume) support of the samples differ considerably.
For Kuriskova, the best method of comparison was to examine the grade distributions of each data set within the Main Zone wireframes, where the bulk of the total resource is located. The gamma data at 0.5m composites, from within the gamma wireframe for the Main Zone, were compared in a cumulative frequency plot with the assay data as 0.5m composites, from within the assay wireframe for the Main Zone. The grade distribution plots are nearly identical, providing confidence that the historical gamma-only data accurately represents the deposit grades. This type of analysis is just one of many concerns in dealing with uranium resource estimation with historical project databases.
By providing uranium expertise, SRK has helped Tournigan better understand the Kuriskova deposit, and added value in the process.
Allan Moran: amoran@srk.com
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