During licence Year 11, the lithological logs were digitised and are now presented for the remaining eight holes of the first drilling program (completed in 2002), together with the holes from the second (2003), and third (2004) drilling programs....
During licence Year 11, the lithological logs were digitised and are now presented for the remaining eight holes of the first drilling program (completed in 2002), together with the holes from the second (2003), and third (2004) drilling programs. Major advances have been made in understanding the geomorphology and sub surface geology of the island following a geomorphological study completed by consultant Richard Russell. This involved a field visit to the island, and examination of diamond core stored in Adelaide. A separate study was completed on the Cainozoic sediments of Flinders Island utilising drill core from the first drilling program and included palynological work. During licence Year 12, no field work was undertaken by Flinders Exploration Limited in the project area due to delays in the ASX listing of Flinders Exploration. Work completed by Orogenic Exploration during the current reporting period has included the determination of the trace element concentrations of chromite, ilmenite and pyrope mineral grains using laser ablation ICP-MS as part of an ongoing study at the GEMOC National Key Centre in Macquarie University (Sydney). The trace elements of chromite indicate that the minerals are sourced from a kimberlite rock. The trace elements of the pyrope indicate the geothermal gradient entered the diamond window, and possible was around 40 mWm-2 at the time the kimberlite was erupted. The Cr-diopside mineral microprobe data was examined by Dr Greg Yaxley from The Australian National University, but no geothermal gradient information for Flinders Island could be obtained due to the lack of diopside which could have crystallised with pyrope or orthopyroxene present. The interpretation of the trace elements analysed within the indicator minerals recovered from Flinders Island support the previous interpretations that these grains are sourced from a kimberlite and should be diamondiferous. During licence Year 13, no active exploration was completed on the project area. Licence Years 14 and 15 were reported jointly, covering the period 4th January 2012 to 3rd January 2014. Early in 2013 Flinders Mines Ltd ceased to be involved in the Project and thus allowing Kalyan Resources Pty Ltd, to acquire the 80% equity previously held by Tawana. In 2013 following the withdrawal of Flinders Mines, a high-resolution magnetic survey was completed, ASTER satellite data for the area was examined and a review of all previous data was undertaken. The ground magnetic survey was completed by Orogenic Exploration and covered an area of 0.97 km2 comprising over 60 line-km of date with readings taken every 50 cm. The survey was designed to cover the subsurface sediment filled Gem Palaeovalley which is known to contain kimberlite indicator grains in the northern deeper parts of the sediment sequence. There is very good correlation with the new ground magnetic data and the existing total magnetic intensity (TMI) data acquired over the same area as part of the UTS aerial survey in 2002. During licence Year 16, two programs of surface rock (16) and loam (2) sampling were completed which also incorporated the collection of historical drill chip samples for heavy mineral kimberlite indicator and microdiamond analyses. Processing is still progressing on most samples but from 26 samples completed three new microdiamonds have been recovered from two samples. A total of 338 microprobe analyses have been completed confirming the highly prospective kimberlitic nature of grains. This was the first time the ?0.3 mm fraction of samples from Finders Island have been examined for microdiamonds and it has proved very successful. In December 2014, an aircore drilling program commenced with the completion of 26 holes for 773 m. Average depth of the hole was 29.7 m and each hole was completed into at least three metres of granite. Magnetic susceptibility and pXRF analyses were taken on all 1 m intervals and large composite samples have been sent to Perth of indicator and microdiamond analyses. No kimberlite was visually observed but laboratory results are still pending. During licence Year 17, the results from the 230 surface rock, loam scrape and aircore drillhole samples which were collected in late 2014 and processed for kimberlite indicator minerals and microdiamonds became available. Systematic logging and sampling of the drill spoils was undertaken aimed at understanding the stratigraphy and any stratigraphic controls on the distribution of the often-abundant indicator mineral occurrences which were reported in many of the historic drill samples. The program was successful in that abundant indicator minerals were found to be in restricted bands within an apparent fossil strand line within the Gem Pan area. Processing was also completed on 1.054 tonnes of FSG drill chip material from 2004 which resulted in the recovery of 4 microdiamonds and numerous chromite grains. The total number of diamonds recovered from Flinders Island to date is twenty-four of which 13 were microdiamonds and 11 are macro-diamonds. Kalyan Resources commenced their second phase of aircore drilling in February 2015, with 13 holes drilled for 335.5 m, with each hole terminated once at least 2 m of granite had been penetrated. Magnetic susceptibility and pXRF analyses were taken on all holes at one metre intervals and 105 systematic large composite samples were sent to Perth for the recovery of indicator minerals and microdiamonds. No kimberlite was observed in the drill chips, but kimberlite indicator minerals and diamonds reported in some of the sediments overlying the clay layer. Drillhole FSH20 intersected abundant kimberlitic chromite in a sandy clay overlying the granite basement at a depth of 37-40 m in the basement of the Gem Channel. If this single result can be confirmed with further drilling it could potentially provide Kalyan with a vector to locate a source for the indicator minerals. Kalyan contracted consultant Keith Jones to complete an assessment of the extensive geophysical data available across Flinders Island. He concluded that the complex magnetic signature of the granite and the conductive nature of the Tertiary clays will make it difficult to define geophysical targets on the island. A study was also made of the mineral grain morphology of drill chips from 12 historical drillholes by consultant mineralogist Bruce Michelly. The conclusion from this report is that considering the wear and indicator population characteristics none of the kimberlitic indicator mineral grains reviewed have experienced extensive, multiple cycles or long-distance transport in an alluvial environment. During licence Year 18 to 3rd January 2017, Kalyan conducted desktop modelling work utilising the information and results that it had gained from its two phases of drilling that it had conducted between 2014 to 2016. The substantial information gained over the course of these two drill programs, together with the numerous results obtained, have taken a significant amount of time to understand within a regional context. During licence Years 19 and 20 to 3rd January 2019, Kalyan continued desktop studies utilising the information and results that it had gained from previous drilling programs and surface sampling that it had conducted in the period 2014 to 2016.
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