REG - Berkeley Energia - DFS confirms Salamanca as a low cost producer <Origin Href="QuoteRef">BKY.AX</Origin> - Part 10
14/07/2016 07:46
- Part 10: For the preceding part double click ID:nRSN1376Ei
No changes have been made to any of the drilling data reported in previous ASX releases. The purpose of this release is
presentation of an update to the mineral resource estimate based on improved definition of the mineral resource at the selected
mining unit block size of 5 x 5 x 6m (X x Y x Z).
Data aggregation methods In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (eg cutting of high grades) and cut-off grades are usually Material and should be stated. Previously reported drill intersections are based on chemical assay data and are calculated using a 200ppm U3O8cut-off, no high
grade cut, and may include up to 2m of internal dilution.
Where aggregate intercepts incorporate short lengths of high grade results and longer lengths of low grade results, the procedure used for such aggregation should be stated and some typical examples of such aggregations should be shown in detail. High grade intervals that are internal to broader zones of uranium mineralisation are reported as included intervals.
The assumptions used for any reporting of metal equivalent values should be clearly stated. No metal equivalent values were used.
Relationship between mineralisation widths and intercept lengths These relationships are particularly important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature should be reported. All drilling was planned in such a way as to intersect expected mineralisation in a perpendicular manner. The uranium
mineralisation is interpreted to be flat lying to shallowly dipping so all of the RC holes were drilled vertically.
If it is not known and only the down hole lengths are reported, there should be a clear statement to this effect (eg 'down hole length, true width not known'). The reported down-hole intervals are interpreted to approximate true widths.
Diagrams Appropriate maps and sections (with scales) and tabulations of intercepts should be included for any significant discovery being reported These should include, but not be limited to a plan view of drill hole collar locations and appropriate sectional views. Appropriate diagrams, including a drill plan and cross sections, are included in the main body of this release.
Balanced reporting Where comprehensive reporting of all Exploration Results is not practicable, representative reporting of both low and high grades and/or widths should be practiced to avoid misleading reporting of Exploration Results. No new exploration results are available. All drilling and other information has been reported in previous ASX releases.
Other substantive exploration data Other exploration data, if meaningful and material, should be reported including (but not limited to): geological observations; geophysical survey results; geochemical survey results; bulk samples - size and method of treatment; metallurgical test results; bulk density, groundwater, geotechnical and rock characteristics; potential deleterious or contaminating substances. Down-hole gamma logging of all Berkeley holes was undertaken to provide eU3O8 data. Comparison of eU3O8 data with chemical assay
data have shown that on average eU3O8 tends to underestimate at higher grades (>500ppm) and overestimate at lower grades
(<200ppm). The Mineral Resource Estimate (MRE) reported in this release was estimated using chemical assay data as the primary
method for grade estimation in the modelling process. eU3O8 data was used for grade estimation process when chemical assay data
was not available. The Company has reported the results of a PFS for the Salamanca Project which includes the Retortillo
deposits (refer ASX Announcement dated 26 September 2013). The PFS included hydrogeological, geotechnical, mining, metallurgical
and process engineering studies, as well as environmental impact assessments.
Further work The nature and scale of planned further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). Further work planned for the Retortillo deposits includes additional infill drilling focused on improving geological confidence
and resource classification of open pit areas scheduled to be mined post the initial two years of production (based on the
PFS).Geological studies will include detailed interpretation of lithology, structure and weathering and an assessment of
potential relationships between these factors and uranium grade distribution. Further work is also planned on a number of other
exploration targets within the Retortillo Region.
Diagrams clearly highlighting the areas of possible extensions, including the main geological interpretations and future drilling areas, provided this information is not commercially sensitive. N/A
N/A
Section 3 Estimation and Reporting of Mineral Resources
(Criteria listed in the preceding section also apply to this section.)
Database integrity Measures taken to ensure that data has not been corrupted by, for example, transcription or keying errors, between its initial collection and its use for Mineral Resource estimation purposes. Drill hole data is stored in a password protected relational database (Access). Drill data recorded in digital Excel templates
is transferred to the database by the project geologist who is responsible for reviewing and validating the data. Assay data is
received from the external laboratories in digital format and is loaded directly into the database after QA/QC has been checked
and validates the rest of assays.Geological logging is restricted to appropriate codes relevant to the local geology,
mineralisation, weathering and alteration setting. A copy of the master database is linked to Surpac mining software for Mineral
Resource Estimation.
Data validation procedures used. Database validation checks including collar survey position, down hole survey control, assay limits, eU3O8 profiles, sample
intervals and logging codes are completed prior to the data being transferred to the master database.
Site visits Comment on any site visits undertaken by the Competent Person and the outcome of those visits. Sampling techniques and procedures, as well as QA/QC data, are reviewed internally an ongoing basis. Malcolm Titley, (CP,
Geology Consultant, Maja Mining Limited) has reviewed the sampling techniques, procedures, data and resource estimation
methodology. He has undertaken a number of site visits, the latest being in August 2015, to review and inspect the application
of these procedures. He concludes that the sampling and analytical results available are appropriate for estimation of the
Mineral Resource.
If no site visits have been undertaken indicate why this is the case. Site visits have been undertaken.
Geological interpretation Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. The confidence of the geological interpretation is appropriate for the current level of resource estimation. The resource is
defined within mineralised envelopes which encompass all zones of significant mineralisation.
Nature of the data used and of any assumptions made. Geology and mineralisation interpretation is based on geological logging and sample assays derived from RC and DD drilling,
along with cross sectional interpretations which include surface mapping information and geophysical studies.
The effect, if any, of alternative interpretations on Mineral Resource estimation. Structural studies show dips of structures vary between 50° and 80° however; the uranium mineralisation has undergone supergene
remobilisation and is interpreted to be flat lying to shallowly dipping and generally within 100m from surface.
The use of geology in guiding and controlling Mineral Resource estimation. On the deposit scale the uranium grade is controlled by both lithology and structure, while on a local scale the grade is
interpreted to be influenced by supergene processes.
The factors affecting continuity both of grade and geology. Geological logging and uranium assay of samples from drill holes has demonstrated the continuity of the grade and lithology
between mineralised sections. Breaks in continuity are likely due to structural offsets, some of which have been observed or
interpreted from surface mapping.
Dimensions The extent and variability of the Mineral Resource expressed as length (along strike or otherwise), plan width, and depth below surface to the upper and lower limits of the Mineral Resource. The main deposit (including a small satellite zone) covers an area of approximately 3km by 0.6km. A second smaller deposit to
the NW covers an area of approximately 2.3km by 0.2km. The mineralisation at both deposits generally occurs within 100m of
surface.
Estimation and modelling techniques The nature and appropriateness of the estimation technique(s) applied and key assumptions, including treatment of extreme grade values, domaining, interpolation parameters and maximum distance of extrapolation from data points. If a computer assisted estimation method was chosen include a description of computer software and parameters used. A mineralised envelope is created encompassing all zones of significant mineralisation. A number of different domains have been
interpreted based on a broad mineralisation envelope at a nominal cut-off of 40ppm U3O8.Geostatistical variogram modelling was
used to determine appropriate parameters for estimation of uranium grade using Ordinary Kriging (OK) (for all Domains) followed
by the application of Uniform Conditioning (UC) and Local Uniform Conditioning (LUC) using Isatis Software, in order to simulate
the grade tonnage distribution based on a Selective Mining Unit (SMU) of 5m x 5m x 6m for all Domains.Surpac software was used
for mineralisation volume interpretation and Isatis for uranium grade estimation.Four sources of drillhole uranium grade data
was used, the proportions of data within the mineralised volume by length are:· Chemical U3O8 (ppm): 56.3%· Radiometric
Equivalent (ppm): 30.6%· Portable XRF (ppm): 0.8%· Background waste values based on XRF and Gamma probe results (10ppm
U3O8): 12.3%A number of holes which were used to determine the mineralisation volume were excluded from the grade estimation
process. These consisted of 32 JEN holes where the radiometric equivalent value indicated mineralisation but the eU3O8 value was
composited over the entire mineralisation length, resulting in these holes being unsuitable for local grade estimation.The drill
hole spacing is nominally 50m by 50m, with infill spacing at 35m by 35m within the Measured Resource areas and part of the
Indicated Resource.Eight mineralisation domains were identified at Retortillo (R2, R3, R4, R5, R6, R7, S1 and S2). 1m samples
composites were used to estimate grade into 20m by 20m by 6m parent blocks with 5m by 5m by 6m blocks used for UC selectivity
conditioning.In order to reduce local bias due to extreme high grades, top cuts were applied: · R2: 1,100ppmU3O8· R3:
1,800ppmU3O8· R4: not applied· R5: 3,800ppmU3O8· R6: 2,000ppmU3O8· R7: not applied· S1: 2,500ppmU3O8·
S2: 2,500ppmU3O8Appropriate search volumes, minimum and maximum sample numbers and top cutting strategy were used based on
the results of Kriging Neighbourhood Analysis. The variogram nugget % and maximum ranges in the order of major, semi-major and
minor per domain in meters are presented below:· R2: 31%/74/72/55· R3: 18%/105/90/23· R4: 36%/44/31/25 taken from
R5 as insufficient data· R5: 36%/44/31/25· R6: 32%/79/50/109· R7: 32%/79/50/109 taken from R6 as insufficient
data· S1: 31%/65/85/38· S2: 30%/128/85/27In-situ dry bulk densities were assigned based on zones of weathering
intensity and used to estimate tonnage.
The availability of check estimates, previous estimates and/or mine production records and whether the Mineral Resource estimate takes appropriate account of such data. The current resource estimate was compared with the previous resource estimate (April 2015) which was based on a more
constrained mineralisation envelope and Ordinary Kriging grade estimation with no adjustment for mining selectivity. The updated
MRE has 4% less tonnes with a 15% higher grade for a 7% increase in metal. This increase in grade and metal was anticipated as a
result of modelling the mineralisation using
- More to follow, for following part double click ID:nRSN1376EkRecent news on Berkeley Energia
See all newsREG - Berkeley Energia - Quarterly Report March 2025
AnnouncementREG - Berkeley Energia - Change in Substantial Holder
AnnouncementREG - Official List - Official List Notice
AnnouncementREG - Stock Exch Notice - Admission to Trading - 26/10/2022
AnnouncementREG - Berkeley Energia - Admission of shares to trading
Announcement