Yahoo FinanceBASE RESOURCES LIMITED - Kwale North and Bumamani Resources Estimates
AIM and Media Release
19 February 2021
BASE RESOURCES LIMITED
Updated Kwale North Dune and Maiden Bumamani Mineral Resources Estimates
Key Points
As part of the pre-feasibility study currently underway to assess the viability of mining the Kwale North Dune and Bumamani deposits, seeking to extend the mine life of Kwale Operations, additional drilling and mineralogy assessments have been conducted.
The Kwale North Dune Mineral Resources estimate has increased by 13% to 194 million tonnes at an average HM grade of 1.5%, containing 2.9Mt HM, based on a 1% HM cut-off grade.
99% of the Kwale North Dune Mineral Resources estimate is now reported in the Measured and Indicated categories.
The maiden Bumamani Mineral Resources estimate is 5.9 million tonnes at an average HM grade of 1.9%, containing 0.115Mt HM, based on a 1% HM cut-off grade.
The pre-feasibility study for the Kwale North Dune and Bumamani deposits is due for completion early in Q2 2021.
African mineral sands producer, Base Resources Limited (ASX / AIM: BSE) (Base Resources) is pleased to provide an update to the Kwale North Dune Mineral Resources (2021 Kwale North Dune Mineral Resources) estimate and announce a maiden Bumamani Mineral Resources estimate (2021 Bumamani Mineral Resources) at its 100% owned and operated mineral sands operations in Kwale County, Kenya (Kwale Operations).
The 2021 Kwale North Dune Mineral Resources and 2021 Bumamani Mineral Resources estimates are being presented together because of the close proximity of the underlying deposits and as these deposits are the subject of a single pre-feasibility study (the Kwale North Dune PFS) being undertaken to assess their potential to extend the mine life of Kwale Operations. The Kwale North Dune PFS commenced in early 2020 and is due for completion early in the second quarter of 2021.
Since announcement of the maiden JORC 2012 North Dune Mineral Resources estimate in May 2019 (2019 Kwale North Dune Mineral Resources)1, Base Resources has carried out additional drilling, assaying and mineralogy studies of the Kwale North Dune to improve the confidence of the Mineral Resources estimate and further the Company’s understanding of the deposit. As a result of this additional work, 99% of the 2021 Kwale North Dune Mineral Resources estimate is now reported in the Measured and Indicated categories. Material tonnage for the 2021 Kwale North Dune Mineral Resources estimate has also increased by 13% and contained heavy mineral (HM) has increased by 12% from the 2019 Kwale North Dune Mineral Resources estimate.
The 2021 Kwale North Dune Mineral Resources are now estimated to be 194 million tonnes (Mt) at an average HM grade of 1.5% for 2.9Mt of contained HM, at a 1% HM cut-off grade.
The Bumamani deposit is situated approximately 1.5km south of the North Dune deposit (Figure 1) and was discovered by Base Resources in 2017 when drilling to test for mineralisation in the north-east sector of the Kwale Prospecting Licence PL/2018/0119 (PL119). At that time, taking into account the results at hand and the small size of the deposit indicated by such results, it was decided that any Mineral Resources estimate would be deferred until the full drilling program planned for the north-east sector was able to be completed and the full results incorporated into the estimation process. Due to ongoing community access issues, Base Resources has not been able to complete that program. However, with commencement of the Kwale North Dune PFS, the Bumamani deposit has now been revisited due to its proximity to the Kwale North deposit and a Mineral Resources estimate completed to allow its inclusion in that study.
The maiden 2021 Bumamani Mineral Resources estimate was developed from 2,977.5m of drilling from 183 holes and is 5.9Mt at an average HM grade of 1.9% for 0.115Mt of contained HM, at a 1% HM cut-off grade.
The 2021 Kwale North Dune Mineral Resources and the 2021 Bumamani Mineral Resources estimates are reported in accordance with the JORC Code. Base Resources has a net attributable interest of 100% in the 2021 Kwale North Dune Mineral Resources and the 2021 Bumamani Mineral Resources.
The information prescribed by the ASX Listing Rules, including a summary of the information material to understanding each Mineral Resources estimate in respect of the prescribed matters, is set out in the sections below. For each Mineral Resources estimate, such information should be read in conjunction with the explanatory information provided in respect of the applicable estimate for the purposes of Sections 1 to 3 of Table 1 of the JORC Code - see Appendix 1 to this announcement in the case of the 2021 Kwale North Dune Mineral Resources estimate and Appendix 2 in the case of the 2021 Bumamani Mineral Resources estimate.
Figures (graphics) referenced in this announcement have been omitted. A full PDF version of this announcement, including all figures (graphics), is available from Base Resources’ website: https://baseresources.com.au/investors/ announcements/.
[Note (1): Refer to Base Resources’ market announcement “Mineral Resource for Kwale North Dune deposit” released on 1 May 2019, which is available at https://baseresources.com.au/investors/announcements/]
Table 1: 2021 Kwale North Dune Mineral Resources estimate compared with the 2019 Kwale North Dune Mineral Resources estimate.
2021 | 2019 | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Table subject to rounding differences, resources estimated at a 1% HM cut-off grade.
Table 2: Maiden 2021 Bumamani Mineral Resources estimate.
2021 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Table subject to rounding differences, resources estimated at a 1% HM cut-off grade.
Further information relevant to both Mineral Resources estimates
Kwale Operations is located on Special Mining Lease 23 (SML 23), which lies within PL119. The Prospecting Licence covers an area of 88.7km2, which includes the Kwale North and Bumamani deposits, and is located approximately 50 kilometres south of Mombasa and approximately 10 kilometres inland from the Kenyan coast (Figure 1).
The Kwale Project initially comprised three areas that contained concentrations of heavy minerals. They were the South Dune, Central Dune (now totally depleted by mining and currently the repository for sand tailings from the South Dune) and the North Dune deposits (Figure 2), with the Bumamani deposit only being discovered in 2017 after mining operations had commenced.
The project was initially owned by Tiomin Resources Inc. (Tiomin) which conducted drilling in 1997 and then by Base Titanium Limited (a wholly owned subsidiary of Base Resources) which purchased the project late in 2010 and commenced confirmatory drilling of the Central, South and North Dune deposits. The North Dune deposit was initially excluded from the project’s Mineral Resources on the basis of HM grade and the then prevailing economic conditions. However, in 2018, it was decided to re-evaluate the potential of the North Due in light of improved economic conditions, refined resource definition methodology and with insights gained from five years of operations on the Central Dune. Following that decision, the 2019 Kwale North Dune Mineral Resources estimate was announced.
The rocks of the area are of sedimentary origin and range in age from Upper Carboniferous to Recent. Three divisions are recognised: the Cainozoic rocks, the Upper Mesozoic rocks (not exposed within the area) and the Duruma Sandstone Series giving rise to the dominant topographical feature of the area: the Shimba Hills. The Shimba grits and Mazeras sandstone are of Upper Triassic age and form the Upper Duruma Sandstone.
The Magarini sands form a belt of low hills running parallel to the coast. They rest with slight unconformity on the Shimba grits and Mazeras sandstone. This formation was deposited during Pliocene times and consists mainly of unconsolidated fluviatile sediments derived from the Duruma Sandstone Series.
The Kwale deposits are an aeolian subset of the Magarini sands and are generally poorly stratified and contain a fraction of clay, which for the North Dune and Bumamani deposits is approximately 37% and 21%, respectively. Heavy minerals, mainly ilmenite, rutile and zircon, are locally concentrated and are abundant in some places, giving rise to the deposits.
Further information specific to the 2021 Kwale North Dune Mineral Resources estimate
The geological interpretations for the Kwale North Dune deposit considered the data in the drill logs, HM assay results, microscopic logging of HM sinks, detailed mineralogy and knowledge gained from mining the Central Dune and South Dune deposits. Four geological domains have been identified at the Kwale North Dune deposit. These were used and honoured during the geological modelling (Figure 3).
The uppermost zone at the Kwale North Dune deposit, referred to as Ore Zone 1, is a dark brown, predominantly fine grained, well sorted silty sand with very little induration and is similar to the Ore Zone 1 units in the other Kwale deposits. Mineralogically, it is characterised by clean, glossy and rounded HM grains with an average valuable heavy mineral (VHM) content of approximately 75%.
Ore Zone 4 lies below Ore Zone 1, with an indurated paleo-surface separating the two zones, as observed in the field through difficult drill bit penetration, and in HM sink logs, exhibiting elevated iron oxides. The Ore Zone 4 host is higher in slimes with difficult washability and the grain sorting is generally poor. It is slightly lower in VHM content (71%), often with elevated iron oxides and alumino-silicate minerals (kyanite, andalusite and sillimanite). Ore Zone 4 is considered a fluvial deposit based on the difficulty of wash and the poor grain sorting.
Ore Zone 5 lies below Ore Zone 4 and is separated from that zone by a lateritic paleo-surface and is also hosted in a fluviatile clay-rich, poorly sorted formation. It is distinguished mineralogically by an increased amount of almandine garnet that reports to the magnetic fraction, significantly increasing magnesium, manganese, aluminium and silicon in the oxide chemistry. As a result of this, Ore Zone 5 has a notably lower average VHM content (44%).
The Basement Zone lies below Ore Zone 5 and is typically hosted in weathered variants of the Mesozoic (Permo-Triassic) Duruma Sandstones. It does contain mineralisation which was reported in the 2019 Kwale North Dune Mineral Resources estimate as Ore Zone 10. However, it has a VHM content of just 10% being predominantly titano-haematite (<40% TiO2) to which no value is ascribed, with zircon enrichment in the non-magnetic fraction. This mineralisation was assessed at scoping level. It is not considered to hold potential for eventual economic extraction due to its low VHM content, depth of burial, high slime content (42%), high grade variability, presence of induration and the fact that most of it lies below the water table (significantly increasing the cost and complexity of mining) and is therefore not reported.
For Ore Zones 1, 4 and 5, a strong correlation between the field logs, HM sink logs and XRF oxide chemistry and QEMSCAN mineralogy gives confidence to these interpretations.
Following acquisition of the Kwale Project, subsequent resource drilling by Base Resources’ wholly-owned subsidiary, Base Titanium Limited, of the Kwale North deposit was completed using the reverse circulation, air core (RCAC) method and conducted in three campaigns: November 2010, December 2012 to April 2013 and June 2018 to May 2019 (Figure 4). A total of 745 holes were drilled for 27,429 metres and generated 15,441 samples for assay. Tiomin drilled 37 holes in 1997 but, due to poor twinned hole assay repeatability at other areas of the Kwale Project, no Tiomin drilling information was used by Base Resources for the 2019 Kwale North Dune Mineral Resources estimate and this is also the case of the 2021 Kwale North Dune Mineral Resources.
The predominantly three metre sample intervals in the 2010 and 2012/13 drilling were replaced by sampling at 1.5 metre intervals for the 2018/19 drill program to provide greater control on geological boundaries. Sample sizes averaged close to 3kg at this sample interval when collecting 25% of the rotary splitter cycle. Samples were dried, weighed, and screened for material less than 45 micrometres (slimes) and +1 mm (oversize).
Approximately 100 grams of the screened sample was subjected to a HM float/sink technique using the heavy liquid, lithium polytungstate (LST) with a specific gravity of 2.85 grams per cubic centimetre. The resulting HM concentrate was dried and weighed as were the other separated constituent size fractions (the minus 45 micrometre material being calculated by difference).
Mineral assemblage analyses were conducted by Base Resources to characterise the mineralogical and chemical characteristics of specific mineral species and magnetic fractions. These mineral assemblage samples were subjected to magnetic separation using a Mineral Technologies induced-roll magnetic separator which captures magnetic (mag), middling (mid) and non-magnetic (non-mag) fractions. The mid and mag fractions were combined and, with the non-mag fraction, were subjected to XRF analysis using a Bruker, S8 Tiger XRF.
Data from the mag and non-mag XRF analyses are processed through an algorithm (Minmod) that runs approximately 100,000 iterations in assigning key chemical species to derive a calculated mineralogy determination.
Drill hole collar and geology data was captured by industry-specific, field logging software with on-board validation. Field and assay data were managed in a MS Access database and subsequently migrated to a more secure SQL database.
Standard samples were generated and certified for use in the field and laboratory. Accuracy of HM and slimes (SL) analysis was verified by using the standard samples and monitored using control charts. Standard errors greater than three standard deviations from the mean prompted batch re-assay. A standard precision analysis was conducted on the key assay fields: HM, SL and Oversize (OS) for both laboratory and field duplicate samples. Normal scatter and QQ plots were prepared for HM, SL and OS for laboratory and field duplicates.
A twin drilling program was introduced for the 2018 program to quantify short-range variability in geological character and grade intersections. A water injection versus dry drilling assessment was included in the twin drilling analysis. Field and laboratory duplicate, standard and twin drilling analysis show adequate level of accuracy and precision to support resource classifications as stated.
A topographic DTM was prepared by Base Resources based on a LIDAR survey.
Construction of the geological grade model was based on coding model cells below open wireframe surfaces, comprising topography, geology (Ore Zones 1, 4, and 5) and basement (Figure 3). Model cell dimensions of 50m x 50m x 1.5m in the XYZ orientations were utilised.
Interpolation was undertaken using various sized search ellipses to populate the model with primary grade fields (HM, SL and OS), and index fields (hardness, induration percent, mineralogy). Inverse distance weighting to a power of three was used for primary assay fields whilst nearest neighbour was used to interpolate index fields. Figure 5 shows an oblique view of the model coloured by HM grades.
A fixed bulk density of 1.7 (t/m3) was applied to the 2021 Kwale North Dune Mineral Resources model. This bulk density was selected based on operational experience in the Kwale Central and South Dune deposits and because no bulk density sampling was undertaken. This is considered to be a conservative estimate of bulk density.
The Kwale North Dune deposit, being similar in nature to the Kwale South Dune deposit currently being mined, is considered amenable to being mined and processed in the same way. That is, by using the existing plant and equipment at the Kwale Operations: hydraulic mining, spiral concentrator and mineral separation plant with magnetic, electrostatic and further gravity separation. The only departure from current methodology is that, for the Kwale North Dune deposit, the fine and coarse tailings are likely to be co-disposed together. Apart from that, there is no indication that the mining, metallurgical and operating cost modifying factors for the Kwale North deposit would be materially different to those derived from mining the Kwale South Dune deposit.
The criteria used for classification was primarily the drill spacing (predominantly 100m x 100m) and sample interval (predominantly 1.5m), with consideration also given to the continuity of mineral assemblage information. The ore zones exhibit spatially different classifications mainly because of differing density of mineralogical information and variography. The reason for the increased material tonnes between the 2019 and 2021 Kwale North Dune Mineral Resources estimates is that the area covered by assays has increased. The reason for the increased confidence levels in the 2021 Kwale North Dune Mineral Resources estimate is refined variography assessments for Ore Zones 1 and 5 which indicate increased ranges in the primary and/or secondary directions of grade continuity compared to the 2019 Kwale North Dune Mineral Resources. The 2021 Kwale North Dune Mineral Resources estimate used a 1% HM bottom cut because the economic cut-off grade at the nearby Kwale South Dune deposit mine is near to this, and resource estimates for Kwale Operations have historically been reported at this cut-off grade. Figures 4, 6 and 7 show the distribution of the resource classifications for Ore Zones 1, 4 and 5, respectively.
Further information specific to the 2021 Bumamani Mineral Resources estimate
The geological interpretations for the Bumamani deposit considered the data in the drill logs, HM assay results, microscopic logging of HM sinks, detailed mineralogy and knowledge gained from mining the Central Dune and South Dune deposits. Three geological domains have been identified at the Bumamani deposit. These were used and honoured during the geological modelling (Figure 8).
The uppermost zone at the Bumamani deposit, referred to as Ore Zone 1 (Figure 9), is a dark brown, predominantly fine grained, well sorted silty sand with very little induration and is similar to the Ore Zone 1 units in the other Kwale deposits. It averages 1.9% HM, 21% SL and 4% OS. The zone gets sandier to the east with reduced silt content. Mineralogically it is characterised by clean, glossy and rounded HM grains with an average VHM content of approximately 70% VHM.
Ore Zone 4 (Figure 10) lies below Ore Zone 1, with the two zones separated by a lateritic paleo-surface which may imply a time-gap in depositional history. Ore Zone 4 is a fluviatile unit represented locally with poorly sorted sandy clays and gritty sands. The Ore Zone 4 domain averages 1.8% HM, 23.6% SL and 6.4% OS. Ore Zone 4 is mineralogically similar to Ore Zone 1.
The Basement Zone at the Bumamani deposit lies beneath Ore Zone 4 and comprises compacted clays, sandy-clays, limestone and fluvial sands. The grain sizes range from silt to pebbles and boulders, with generally poor sorting and is characterised by trace concentrations of HM typically with low VHM content.
For Ore Zones 1 and 4, a strong correlation between the field logs, HM sink logs and XRF oxide chemistry and QEMSCAN mineralogy gives confidence to these interpretations.
Drilling by Base Resources’ wholly-owned subsidiary, Base Titanium Limited, of the Bumamani deposit was completed using the RCAC method and conducted in two campaigns in 2017 and 2018, both employing 76mm diameter, 3m long NQ drill rods. A total of 183 holes were drilled for 2,977.5m at 1.5m sampling intervals and generated 1,968 assayed samples. Holes were drilled 50m apart on lines 100m apart. Samples were split using a rig mounted rotary splitter which delivered an average of 2.7kg of dry sample per interval. Samples were dried, weighed, and screened for material less than 45 micrometres (slimes) and +1mm (oversize).
Approximately 100 grams of the screened sample was subjected to a HM float/sink technique using the heavy liquid, lithium polytungstate (LST) with a specific gravity of 2.85 grams per cubic centimetre. The resulting HM concentrate was dried and weighed as were the other separated constituent size fractions (the minus 45 micrometre material being calculated by difference).
Mineral assemblage analyses were conducted by Base Resources to characterise the mineralogical and chemical characteristics of specific mineral species and magnetic fractions. These mineral assemblage samples were subjected to magnetic separation using a Mineral Technologies induced-roll magnetic separator which captures mag, mid and non-mag fractions. The mid and mag fractions were combined and, with the non-mag fraction, were subjected to XRF analysis using a Bruker, S8 Tiger XRF.
Data from the mag and non-mag XRF analyses was processed through the Minmod algorithm that runs approximately 100,000 iterations in assigning key chemical species to derive a calculated mineralogy determination.
Drill hole collar and geology data was captured by industry-specific, field logging software with on-board validation. Field and assay data were managed in a MS Access database and subsequently migrated to a more secure SQL database.
Standard samples were generated and certified for use in the field and laboratory. Accuracy of HM and SL analysis was verified by using the standard samples and monitored using control charts. Standard errors greater than three standard deviations from the mean prompted batch re-assay. A standard precision analysis was conducted on the key assay fields: HM, SL and OS for both laboratory and field duplicate samples. Normal scatter and QQ plots were prepared for HM, SL and OS for laboratory and field duplicates.
A twin drilling program was introduced for the 2018 program to quantify short-range variability in geological character and grade intersections. A water injection versus dry drilling assessment was included in the twin drilling analysis. Field and laboratory duplicate, standard and twin drilling analysis show adequate level of accuracy and precision to support resource classifications as stated.
A topographic DTM was prepared by Base Resources based on a LIDAR survey.
Construction of the geological grade model was based on coding model cells below open wireframe surfaces, comprising topography, geology (Ore Zones 1 and 4) and basement (Figure 8). Model cell dimensions of 50m x 50m x 1.5m in the XYZ orientations were utilised.
Interpolation was undertaken using various sized search ellipses to populate the model with primary grade fields (HM, SL and OS), and index fields (hardness, induration percent, mineralogy). Inverse distance weighting to a power of three was used for primary assay fields whilst nearest neighbour was used to interpolate index fields. Figure 11 shows an oblique view of the model coloured by HM grade.
A fixed bulk density of 1.7 (t/m3) was applied to the 2021 Bumamani Mineral Resources estimate model. This bulk density was selected based on operational experience in the Kwale Central and South Dune deposits and because no bulk density sampling was undertaken. This is considered to be a conservative estimate of bulk density.
The Bumamani deposit, being similar in nature to the Kwale South Dune deposit currently being mined, is considered amenable to being mined and processed in the same way. That is, by using the existing plant and equipment at the Kwale Operations: hydraulic mining, spiral concentrator and mineral separation plant with magnetic, electrostatic and further gravity separation. The only departure from current methodology is that, for the Bumamani deposit (like for the Kwale North Dune deposit), the fine and coarse tailings are likely to be co-disposed together. Apart from that, there is no indication that the mining, metallurgical and operating cost modifying factors for the Bumamani deposit would be materially different to those derived from mining the Kwale South Dune deposit.
The criteria used for classification was primarily the drill spacing (predominantly 100m x 50m) and sample interval (1.5m), with consideration also given to the continuity of mineral assemblage information. The ore zones exhibit spatially different classifications mainly because of differing density of mineralogical information. The 2021 Bumamani Mineral Resources estimate used a 1% HM bottom cut because the economic cut-off grade at the nearby Kwale South Dune deposit mine is near to this, and resource estimates for Kwale Operations have historically been reported at this cut-off grade. Figures 9 and 10 show the distribution of the resource classifications for Ore Zones 1 and 4 respectively.
Competent Persons' Statements
2021 Kwale North Dune Mineral Resources estimate
The information in this announcement that relates to the 2021 Kwale North Dune Mineral Resources estimate is based on, and fairly represents, information and supporting documentation prepared by Mr. Greg Jones, who acts as a Consultant Geologist for Base Resources and is employed by IHC Robbins. Mr. Jones is a Fellow of The Australasian Institute of Mining and Metallurgy and has sufficient experience that is relevant to the style of mineralisation, type of deposits under consideration and activity which he is undertaking to qualify as a Competent Person as defined in the JORC Code and as a Qualified Person for the purposes of the AIM Rules for Companies. Mr. Jones has reviewed this announcement and consents to the inclusion in this announcement of the 2021 Kwale North Dune Mineral Resources estimate and supporting information in the form and context in which that information appears.
2021 Bumamani Mineral Resources estimate
The information in this announcement that relates to the 2021 Bumamani Mineral Resources estimate is based on, and fairly represents, information and supporting documentation prepared by Mr. Scott Carruthers. Mr. Carruthers is a Member of The Australasian Institute of Mining and Metallurgy. Mr. Carruthers is employed by Base Resources, holds equity securities in Base Resources, and is entitled to participate in Base Resources’ long-term incentive plan and receive equity securities under that plan. Details about that plan are included in Base Resources’ 2020 Annual Report. Mr. Carruthers has sufficient experience that is relevant to the style of mineralisation, type of deposits under consideration and activity which he is undertaking to qualify as a Competent Person as defined in the JORC Code and as a Qualified Person for the purposes of the AIM Rules for Companies. Mr. Carruthers has reviewed this announcement and consents to the inclusion in this announcement of the 2021 Bumamani Mineral Resources estimate and supporting information in the form and context in which that information appears.
Forward Looking Statements
Certain statements in or in connection with this announcement contain or comprise forward looking statements.
By their nature, forward looking statements involve risk and uncertainty because they relate to events and depend on circumstances that will occur in the future and may be outside Base Resources’ control. Accordingly, results could differ materially from those set out in the forward-looking statements as a result of, among other factors, changes in economic and market conditions, success of business and operating initiatives, changes in the regulatory environment and other government actions, fluctuations in product prices and exchange rates and business and operational risk management. Subject to any continuing obligations under applicable law or relevant stock exchange listing rules, Base Resources undertakes no obligation to update publicly or release any revisions to these forward-looking statements to reflect events or circumstances after the date of this announcement or to reflect the occurrence of unanticipated events.
No representation or warranty, express or implied, is made as to the fairness, accuracy or completeness of the information contained in this announcement (or any associated presentation, information or matters). To the maximum extent permitted by law, Base Resources and its related bodies corporate and affiliates, and their respective directors, officers, employees, agents and advisers, disclaim any liability (including, without limitation, any liability arising from fault, negligence or negligent misstatement) for any direct or indirect loss or damage arising from any use or reliance on this announcement or its contents, including any error or omission from, or otherwise in connection with, it.
Nothing in this announcement constitutes investment, legal or other advice. You must not act on the basis of any matter contained in this announcement but must make your own independent investigation and assessment of Base Resources and obtain any professional advice you require before making any investment decision based on your investment objectives and financial circumstances. This announcement does not constitute an offer, invitation, solicitation, advice or recommendation with respect to the issue, purchase or sale of any security in any jurisdiction.
Appendix 1 – 2021 Kwale North Dune Mineral Resources estimate
JORC Code, 2012 Edition
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria | Explanation | Comment |
|---|---|---|
Sampling techniques | Nature and quality of sampling (e.g., cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. | Reverse circulation aircore drilling was used to collect downhole samples for the project. |
Drilling techniques | Drill type (e.g., core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g., core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc). | 122 holes in the 2010, 2012/2013 campaigns were drilled with a RCAC Wallis Mantis 75 drill rig using NQ drill tooling of about 76mm in diameter. |
Drill sample recovery | Method of recording and assessing core and chip sample recoveries and results assessed. | Sample condition was logged at the rig as either good, moderate or poor, with good meaning not contaminated and appropriate sample size (recovery), moderate meaning not contaminated, but sample over or under sized, and poor meaning contaminated or grossly over/undersized. |
Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. | Field logging was recorded for all 16,257 fixed, down-hole intervals and was conducted as drilling and sampling proceeded. Logging was based on a representative grab sample that was panned for heavy mineral estimation and host material observations. |
Sub-sampling techniques and sample preparation | If core, whether cut or sawn and whether quarter, half or all core taken. | Rotary split at the sampling cyclone on the rig. Approximately 25% of the original sample retained. Duplicate samples were collected at every 20th sample. The drill rods and cyclone were routinely cleaned between holes using pressurised water to avoid inter-hole contamination. The sample size is considered appropriate for the grain size of the material because the grade of HM is measured in per cent, and a 2.5-5kg sample contains in excess of 50 million grains of sand. |
Quality of assay data and laboratory tests | The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. | The assay process employed included a Sample Preparation stage, completed by BTL staff, followed by a heavy liquid separation (using lithium polytungstate: SG = 2.85g/cm3), completed at Kwale Operations’ site laboratory. |
Verification of sampling and assaying | The verification of significant intersections by either independent or alternative company personnel. | The Kwale North Dune deposit is a moderate to low HM grade, dunal-style accumulation that does not carry excessive mineralisation or suffer from ‘nugget’ effects, typical of other commodities. |
Location of data points | Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. | Proposed drill holes were sited on the ground using hand-held GPS. After drilling, surveyors recorded collar positions via DGPS RTK unit registered to local base stations. The accuracy of the DGPS unit is stated at 0.02m in the X, Y and Z axes. |
Data spacing and distribution | Data spacing for reporting of Exploration Results. | The drill data spacing for the 2018/19 Kwale North Resource drilling was nominally 100m X, 100m Y and 1.5m Z. Variations from this spacing resulted from terrain/traverse difficulties and ground access. |
Orientation of data in relation to geological structure | Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. | With the geological setting being a layered dunal/fluviatile sequence, the orientation of the deposit mineralisation in general is sub-horizontal. All drill holes were orientated vertically to penetrate the sub-horizontal mineralisation orthogonally. |
Sample security | The measures taken to ensure sample security. | Sample residues from the prep stage were transferred to pallets and stored in a locked shed beside the warehouse at Kwale Operations. |
Audits or reviews | The results of any audits or reviews of sampling techniques and data. | In-house reviews were undertaken by the Base Resources’ Resources Manager, Mr. Scott Carruthers who is a Competent Person under the JORC Code. |
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section.)
Criteria | Explanation | Comment |
|---|---|---|
Mineral tenement and land tenure status | Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. | The Kwale North Dune is situated on a Prospecting License (PL) 100% owned by Base Titanium Limited – PL/2018/0119 located in Kwale County, Kenya. Base Titanium Limited is a wholly owned subsidiary of Australian and UK-listed resources company, Base Resources Limited. |
Exploration done by other parties | Acknowledgment and appraisal of exploration by other parties. | In 1996, Tiomin carried out reconnaissance surface and hand-auger sampling. |
Geology | Deposit type, geological setting and style of mineralisation. | The North Dune is part of the extensive Kwale Dune systems comprising of reddish, windblown Magarini sand formations that overlie a sequence of mineralised clay-rich fluviatile units, which in turn overlie a Mesozoic sandstone Base, known as the Mazeras formation. |
Drill hole Information | A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: | Drilling by year (max, min and average depths) used for the resource model build are as follows: See drill hole location plan, Figure 4. |
Data aggregation methods | In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g., cutting of high grades) and cut-off grades are usually Material and should be stated. | Exploration results are not being reported at this time. |
Relationship between mineralisation widths and intercept lengths | These relationships are particularly important in the reporting of Exploration Results. | The deposit sequences are sub-horizontal, and the vertically inclined holes are a fair representation of true thickness. |
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. | See figures 3-7. |
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. | Exploration results are not being reported at this time. |
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. | The proprietary Minmod mineralogy technique, developed and employed by Base Resources, comprises an XRF analysis of the magnetic and non-magnetic fractions of each composite or sample, the results from which are then back-calculated to determine in-ground mineralogy. Minmod represents an improvement on the previous method (Geomod) that was not as effective at determining accessory minerals in the Kwale assemblage. Minmod has been validated by external quantitative analysis (QEMSCAN and SEM EDX) and is considered sufficiently certified to support quoted resource confidence in this report. |
Further work | The nature and scale of planned further work (e.g., tests for lateral extensions or depth extensions or large-scale step-out drilling). | Additional 100 x 100m aircore drilling to in-fill gaps and extend mineralisation in the open NW part of the deposit. |
Section 3 Estimation and Reporting of Mineral Resources
(Criteria listed in section 1, and where relevant in section 2, also apply to this section.)
Criteria | Explanation | Comment |
|---|---|---|
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. | Field data was captured in LogChief logging application and automatically validated through reference to pre-set library table configurations. Assay results were delivered via email in 45 sample batches from Kwale Operations’ site laboratory. These were in the form of CSV text files and imported by batch number directly into the SQL database tables where pre-set algorithms converted weights to percentages and removed the moisture content. The calculated assay results were then checked manually for missing records and out of range or unrealistic values. |
Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. | Base Resources’ Resources Manager Scott Carruthers made one site visit to review the SQL database and the geological interpretations. The Competent Person is satisfied with the integrity of the database as well as the delineation of the geological boundaries. |
Geological interpretation | Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. | The geological interpretation was undertaken by the BTL Exploration Superintendent using field logs and observations, assays, HM sachet logs, XRF oxide chemistry and mineralogy data. The oversize grades were particularly useful in determining the lateritic paleo-surfaces between the geological zones. |
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 2021 Kwale North Dune Mineral Resources estimate is approximately 6,300m along strike and about 1,200m across strike on average. |
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. | The 2021 Kwale North Dune Mineral Resources estimation was undertaken using Datamine Studio RM software. |
Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | The Mineral Resources estimate is on a dry tonnes basis. |
Cut-off parameters | The basis of the adopted cut-off grade(s) or quality parameters applied. | The economic cut-off of Kwale Operations is between 1% and 1.5% HM, and historically Kwale Operations Mineral Resources estimate reporting focuses on a 1% HM cut-off grade. |
Mining factors or assumptions | Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. | It is assumed that the hydraulic mining method used at the neighbouring Kwale Operations would be used. The high slime content and generally low levels of induration in the North Dune deposit provide support for this mining method. This mining method is being re-assessed as part of the Kwale North Dune PFS. |
Metallurgical factors or assumptions | The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | The existing concentrator, modified to accommodate the increased slimes, and mineral separation plant at Kwale Operations are assumed capable of processing the material with recoveries expected to be aligned with present production. |
Environmental factors or assumptions | Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. | Tailing disposal is likely to utilise co-disposal of fine and coarse tails together, initially into the Kwale Central pit void. Once space is available, tailings would be co-disposed into the Kwale North pit void. |
Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. | A fixed dry bulk density of 1.7 (t/m3) was assumed for the Mineral Resource estimation, based on operational experience of mining the Kwale Central Dune and South Dune deposits. |
Classification | The basis for the classification of the Mineral Resources into varying confidence categories. | The Mineral Resource classification for the Kwale North deposit was based on drill hole spacing, sample interval and the distribution and influence of composite mineralogical samples. |
Audits or reviews. | The results of any audits or reviews of Mineral Resource estimates. | Peer review was undertaken by Scott Carruthers, Base Resources’ Resources Manager, with focus on the process and output of the geology interpretation, database integrity, whether wireframes reflect the geological interpretation, and model vs. drill hole grades. Mr. Carruthers was satisfied with these facets. |
Discussion of relative accuracy/ confidence | Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. | Variography was undertaken to determine the drill hole support of the selected JORC classification. |
Appendix 2 – 2021 Bumamani Mineral Resources estimate
JORC Code, 2012 Edition
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections.)
Criteria | JORC Code explanation | Commentary |
|---|---|---|
Sampling techniques | Nature and quality of sampling (e.g., cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. | Reverse circulation aircore drilling was used to collect downhole samples for the project. |
Drilling techniques | Drill type (e.g., core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g., core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc). | 40 holes in the 2017 campaign were drilled with a RCAC Wallis Mantis 80 drill rig using NQ drill tooling of about 76mm in diameter and a drilling capability of 100m. |
Drill sample recovery | Method of recording and assessing core and chip sample recoveries and results assessed. | Sample condition was logged at the rig as either good, moderate or poor, with good meaning not contaminated and appropriate sample size (recovery), moderate meaning not contaminated, but sample over or under sized and poor meaning contaminated or grossly over/undersized. |
Logging | Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. | Field logging was recorded for all 1,968 fixed, down-hole intervals and was conducted as drilling and sampling proceeded. Logging was based on a representative grab sample that was panned for heavy mineral estimation and host material observations. |
Sub-sampling techniques and sample preparation | If core, whether cut or sawn and whether quarter, half or all core taken. | Rotary split at the sampling cyclone on the rig. Approximately 25% of the original sample retained. Duplicate samples were collected at every 20th sample. The drill rods and cyclone were routinely cleaned between holes using pressurised water to avoid inter-hole contamination. The sample size is considered appropriate for the grain size of the material because the grade of HM is measured in per cent, and a 2.5-5kg sample contains in excess of 50 million grains of sand. |
Quality of assay data and laboratory tests | The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. | The assay process employed by Base Resources includes a Sample Preparation stage, completed by BTL staff, followed by a heavy liquid separation (using lithium polytungstate: SG = 2.85g/cm3), completed at Kwale Operations’ site laboratory. |
Verification of sampling and assaying | The verification of significant intersections by either independent or alternative company personnel. | The Bumamani deposit is a moderate to low HM grade, dunal-style accumulation that does not carry excessive mineralisation or suffer from ‘nugget’ effects, typical of other commodities. |
Location of data points | Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. | Proposed drill holes were sited on the ground using hand-held GPS. After drilling, surveyors recorded collar positions via DGPS RTK unit registered to local base stations. The accuracy of the DGPS unit is stated at 0.02m in the X, Y and Z axes. |
Data spacing and distribution | Data spacing for reporting of Exploration Results. | The drill data spacing from the 2017 and 2018 Bumamani Resource drilling programmes was nominally 50m X, 100m Y and 1.5m Z. Variations from this spacing resulted from terrain difficulties or ground access issues. |
Orientation of data in relation to geological structure | Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. | With the geological setting being a layered dunal/fluviatile sequence, the orientation of the deposit mineralisation in general is sub-horizontal. All drill holes were orientated vertically to penetrate the sub-horizontal mineralisation orthogonally. |
Sample security | The measures taken to ensure sample security. | Sample residues from the prep stage were transferred to pallets and stored in a locked storage facility beside the warehouse at Kwale Operations. |
Audits or reviews | The results of any audits or reviews of sampling techniques and data. | Base Resources’ Resources Manager, Mr. Scott Carruthers reviewed the Bumamani geological interpretations, wireframes and assay and mineralogy data interpolations. IHC Robbins Geological Services Manager Greg Jones validated the resource data and reviewed the completed block model. |
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section.)
Criteria | JORC Code explanation | Commentary |
|---|---|---|
Mineral tenement and land tenure status | Type, reference name/number, location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites, wilderness or national park and environmental settings. | The Bumamani deposit is situated on a Prospecting License (PL) 100% owned by Base Titanium Limited – PL/2018/0119 located in Kwale County, Kenya. Base Titanium Limited is a wholly owned subsidiary of Australian and UK-listed resources company, Base Resources Limited. |
Exploration done by other parties | Acknowledgment and appraisal of exploration by other parties. | No known prior exploration has been undertaken by other parties. |
Geology | Deposit type, geological setting and style of mineralisation. | The Bumamani deposit is part of the extensive coastal Plio-Pleistocene Magarini Formation, which comprises aeolian dunal sands and clay-rich fluviatile units that overlie down-faulted Jurassic and Tertiary formations. |
Drill hole Information | A summary of all information material to the understanding of the exploration results including a tabulation of the following information for all Material drill holes: | Drilling by year (max, min and average depths) used for the resource model build are as follows: |
Data aggregation methods | In reporting Exploration Results, weighting averaging techniques, maximum and/or minimum grade truncations (e.g., cutting of high grades) and cut-off grades are usually Material and should be stated. | Exploration results are not being reported at this time. |
Relationship between mineralisation widths and intercept lengths | These relationships are particularly important in the reporting of Exploration Results. | The deposit sequences are sub-horizontal, and the vertically inclined holes are a fair representation of true thickness. |
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. | See figures 8-11. |
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. | Exploration results are not being reported at this time. |
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. | The proprietary MinMod mineralogy technique, developed and employed by Base Resources, comprises an XRF analysis of the magnetic and non-magnetic fractions of each composite or sample, the results from which are then back-calculated to determine in-ground mineralogy. MinMod represents an improvement on the previous method (GeoMod) that was not as effective at determining accessory minerals in the Kwale assemblage. MinMod has been validated by external quantitative analysis (QEMSCAN and SEM EDX) and is considered sufficiently certified to support quoted resource confidence in this report. |
Further work | The nature and scale of planned further work (e.g., tests for lateral extensions or depth extensions or large-scale step-out drilling). | Test pits for bulk sample mineralogy test work. |
Section 3 Estimation and Reporting of Mineral Resources
(Criteria listed in section 1, and where relevant in section 2, also apply to this section.)
Criteria | JORC Code explanation | Commentary |
|---|---|---|
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. | Field data was captured in LogChief logging application and automatically validated through reference to pre-set library table configurations.
|
Site visits | Comment on any site visits undertaken by the Competent Person and the outcome of those visits. | Base Resources’ Resources Manager Scott Carruthers, the Competent Person, has visited the site several times to review assaying, geological interpretation and resource estimation processes, which are considered appropriate. |
Geological interpretation | Confidence in (or conversely, the uncertainty of) the geological interpretation of the mineral deposit. | The geological interpretation and zoning were completed by the BTL Exploration Superintendent by considering field logs, assays, microscopic HM sink descriptions and mineralogy data. |
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 Bumamani Mineral Resource is approximately 1,600m along strike and 500-700m across strike on average. The deposit thickness averages 10m. |
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. | The Bumamani Mineral Resource estimation was undertaken using Geovia Surpac version 6.8 software. |
Moisture | Whether the tonnages are estimated on a dry basis or with natural moisture, and the method of determination of the moisture content. | The Mineral Resources estimate is on a dry tonnes basis. |
Cut-off parameters | The basis of the adopted cut-off grade(s) or quality parameters applied. | The economic cut-off of Kwale Operations is between 1% and 1.5% HM, and historically the Kwale Operations Mineral Resources estimate reporting focuses on a 1% HM cut-off grade. |
Mining factors or assumptions | Assumptions made regarding possible mining methods, minimum mining dimensions and internal (or, if applicable, external) mining dilution. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential mining methods, but the assumptions made regarding mining methods and parameters when estimating Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the mining assumptions made. | It is assumed that the hydraulic mining method used at the neighbouring Kwale Operations would be used. Moderate slime content and generally low levels of induration provide support for this mining method. This mining method is being re-assessed as part of the Kwale North Dune PFS. |
Metallurgical factors or assumptions | The basis for assumptions or predictions regarding metallurgical amenability. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider potential metallurgical methods, but the assumptions regarding metallurgical treatment processes and parameters made when reporting Mineral Resources may not always be rigorous. Where this is the case, this should be reported with an explanation of the basis of the metallurgical assumptions made. | The existing concentrator and separation plant at Kwale Operations are assumed capable of processing the material with recoveries expected to be aligned with present production. |
Environmental factors or assumptions | Assumptions made regarding possible waste and process residue disposal options. It is always necessary as part of the process of determining reasonable prospects for eventual economic extraction to consider the potential environmental impacts of the mining and processing operation. While at this stage the determination of potential environmental impacts, particularly for a greenfields project, may not always be well advanced, the status of early consideration of these potential environmental impacts should be reported. Where these aspects have not been considered this should be reported with an explanation of the environmental assumptions made. | Coarse and fine tailings are intended to be co-disposed together. Initially, into the Kwale Central pit void and subsequently into the Bumamani and Kwale North pit voids. |
Bulk density | Whether assumed or determined. If assumed, the basis for the assumptions. If determined, the method used, whether wet or dry, the frequency of the measurements, the nature, size and representativeness of the samples. | A fixed dry bulk density of 1.7 (t/m3) was assumed for the Mineral Resource estimation, based on operational experience of mining the Kwale Central Dune and South Dune deposits. |
Classification | The basis for the classification of the Mineral Resources into varying confidence categories. | The classification of the Indicated, and Inferred Mineral Resources was supported by the uniform grid spacing of drilling, uncomplicated and consistent geology, relatively good continuity of mineralisation particularly along strike (and supported by the domain controlled variography), confidence in the down hole drilling data and supporting criteria as noted above. |
Audits or reviews | The results of any audits or reviews of Mineral Resource estimates. | An internal review was undertaken by Base Resources’ Resources Manager Scott Carruthers with focus on the process and output of the geology interpretation, database integrity, whether wireframes reflect the geological interpretation, and model vs. drillhole grades. Mr. Carruthers was satisfied with these facets. |
Discussion of relative accuracy/ confidence | Where appropriate a statement of the relative accuracy and confidence level in the Mineral Resource estimate using an approach or procedure deemed appropriate by the Competent Person. For example, the application of statistical or geostatistical procedures to quantify the relative accuracy of the resource within stated confidence limits, or, if such an approach is not deemed appropriate, a qualitative discussion of the factors that could affect the relative accuracy and confidence of the estimate. | Variography was undertaken to determine the drill hole support of the selected JORC classification. |
Glossary
Competent Person | The JORC Code requires that a Competent Person must be a Member or Fellow of The Australasian Institute of Mining and Metallurgy, or of the Australian Institute of Geoscientists, or of a ‘Recognised Professional Organisation’. A Competent Person must have a minimum of five years’ experience working with the style of mineralisation or type of deposit under consideration and relevant to the activity which that person is undertaking. |
DTM | Digital Terrain Model. |
Indicated Resource or Indicated | An Indicated Mineral Resource is that part of a Mineral Resource for which quantity, grade (or quality), densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. |
Inferred Resource or Inferred | An Inferred Mineral Resource is that part of a Mineral Resource for which quantity and grade (or quality) are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade (or quality) continuity. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. |
Inverse distance weighting | A statistical interpolation method whereby the influence of data points within a defined neighbourhood around an interpolated point decreases as a function of distance. |
JORC Code | The Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves 2012 Edition, as published by the Joint Ore Reserves Committee of The Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists and Minerals Council of Australia. |
LIDAR survey | LIDAR is a remote sensing technology that measures distance by illuminating a target with a laser and analysing the reflected light to produce a DTM. |
Measured Resource or Measured | A Measured Mineral Resource is that part of a Mineral Resource for which quantity, grade (or quality), densities, shape, and physical characteristics are estimated with confidence sufficient to allow the application of Modifying Factors to support detailed mine planning and final evaluation of the economic viability of the deposit. |
Mineral Resources | Mineral Resources are a concentration or occurrence of solid material of economic interest in or on the Earth’s crust in such form, grade (or quality), and quantity that there are reasonable prospects for eventual economic extraction. The location, quantity, grade (or quality), continuity and other geological characteristics of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge, including sampling. Mineral Resources are sub-divided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories. |
Minmod | A company developed mineralogy modelling technique, it comprises an XRF analysis of the magnetic and non-magnetic fractions of each composite or sample, the results from which are then back-calculated to determine in-ground mineralogy. |
QEMSCAN | An acronym for Quantitative Evaluation of Materials by Scanning Electron Microscopy, an integrated automated mineralogy and petrography solution providing quantitative analysis of minerals and rocks. |
QQ plot | Quantile plot. Used to graphically compare data distributions. |
RTK | Real time kinematic DGPS uses a base station GPS at a known point that communicates via radio with a roving unit so that the random position error introduced by the satellite owners may be corrected in real time. |
SEM, SEM EDX | A Scanning Electron Microscope is a type of electron microscope that produces images of a sample or minerals by scanning the surface with a focused beam of electrons. EDX is short for energy dispersive X-ray and is commonly used in conjunction with SEM. |
Variography | A geostatistical method that investigates the spatial variability and dependence of grade within a deposit. This may also include a directional analysis. |
XRF analysis or XRF | A spectroscopic method used to determine the chemical composition of a material through analysis of secondary X-ray emissions, generated by excitation of a sample with primary X-rays that are characteristic of a particular element. |
ENDS.
For further information contact:
James Fuller, Manager Communications and Investor Relations
Base Resources
Tel: +61 (8) 9413 7426
Mobile: +61 (0) 488 093 763
Email: jfuller@baseresources.com.au
UK Media Relations
Tavistock Communications
Jos Simson and Gareth Tredway
Tel: +44 (0) 207 920 3150
About Base Resources
Base Resources is an Australian based, African focused, mineral sands producer and developer with a track record of project delivery and operational performance. The company operates the established Kwale Operations in Kenya and is developing the Toliara Project in Madagascar. Base Resources is an ASX and AIM listed company. Further details about Base Resources are available at www.baseresources.com.au
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