Posts Tagged Tempest

Airborne electromagnetic data and inversion models for two regions in Australia

Posted by on Sunday, 3 July, 2011
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New airborne electromagnetic (AEM) data and inversion products have been released for the Frome Embayment area in South Australia. The data were acquired using the TEMPESTTM AEM system during 2010 and cover 95 450 square kilometres in 32 317 line kilometres. The survey primarily targeted potential uranium-bearing mineral systems in the Callabonna Sub-basin of the Frome Embayment and the Lake Eyre Basin on the flanks of the northern Flinders Ranges, continuing to Marree and Cameron Corner and included portions of the Curnamona Province and the northwest Murray Basin.

This data release includes new inversions using the Geoscience Australia layered earth inversion (GA-LEI) algorithm and data products, including point-located ASCII data and geo-located grids, sections and images.

The Phase 2 Frome Embayment TEMPESTTM AEM survey final inversion data and conductivity models will be available from 7 July 2011 as a free download.

New airborne electromagnetic (AEM) inversion products have been released for the Kombolgie VTEMTM AEM survey area in the Northern Territory. Data have been inverted using the layered Earth inversion algorithm software developed at Geoscience Australia.

The Pine Creek AEM Kombolgie survey covered a total of 8800 line kilometres over an area of 32 000 square kilometres and included mapping of subsurface geological features associated with unconformity-related, sandstone-hosted Westmoreland-type and Vein-type uranium mineralisation. The data are capable also of interpretation for other commodities including metals and potable water as well as for landscape evolution studies. The improved understanding of the regional geology to a depth of greater than 1500 metres resulting from the inversion results will be of considerable benefit to mining and mineral exploration companies.

The Phase 2 Kombolgie VTEM AEM survey final inversion data and conductivity models will be available from 7 July 2011 as a free download.


Completion of Airborne Geophysics Survey at Key Lake for uranium

Posted by on Tuesday, 24 May, 2011

Kirrin Resources Inc.  announces the completion of a 1,531 line-kilometre helicopter-borne time-domain electromagnetic geophysical survey of the Key Lake Southwest (‘Key Lake SW’) uranium property located on the southeastern margin of the Athabasca Basin in Saskatchewan, Canada. The survey was flown using Geotech Ltd’s Versatile Time-Domain Electromagnetic (VTEM Plus) geophysical system.

Kirrin has appointed Savaria Geophysics Inc. of Toronto, Ontario, (‘Savaria’) to undertake integration of the prior Fugro airborne Tempest-magnetic survey completed in early 2010 (news release July 6, 2010) and interpretation of the aggregate data acquired by Kirrin. Savaria anticipates submitting its report by end June, following which Kirrin will commence a program of summer fieldwork with the objective of finalizing the selection of drill sites.
The eastern margin of the Athabasca Basin is home to the most productive uranium mines in the world with roughly 25% of the world’s uranium production coming from this area. Kirrin’s target at Key Lake SW is basement-hosted unconformity-type uranium deposits, similar to Cameco’s basement-hosted Millennium deposit, located about 50 km to the northeast; the Phoenix discovery, located about 60 km northeast; and the former Key Lake mine, located about 35 km east-northeast.

Geology

The Key Lake SW property is at the southwest end of the geologically favourable trend that hosts numerous uranium mines and important deposits. Although the property is believed to be somewhat southwest of the margin of the current Athabasca Basin, regolith encountered in old drill holes indicates the Athabasca Supergroup-Wollaston Group basement unconformity was not far above the present ground surface within the property. Discovery of several ‘Ingress style’ uranium deposits, such as Phoenix (up to 117 m below the unconformity), Millennium (up to 100 m below the unconformity), Eagle Point (up to 450 m below the unconformity) and other deposits within the Athabasca Basin, indicates that important uranium deposits can occur from several tens of metres up to a few hundred metres below the unconformity. Hence, there is potential for important basement-hosted uranium deposits to exist within the Key Lake SW property.

The Key Lake SW property is underlain by Aphebian amphibole, pelitic-psammitic gneisses, iron formation and leucogranite. The Aphebian rocks lie on Archean felsic gneisses. The boundary between the Mudjatik and Wollaston Domains passes through the eastern part of the property. Most of the property lies west of this line. Although the sandstone does not cover any of the eight claims now, the assumption that it once did is reasonable. The unconformity uranium deposit model or a derivative should apply to all of the claims in the property. Basement hosted uranium mineralization discovered at Millennium, southwest of the McArthur mine and new zones in the Collins Bay Eagle mine emphasize the potential to discover a similar style of uranium mineralization on the property.

Kirrin explores for rare earth elements and uranium. In addition to its exploration activities, Kirrin seeks to enhance its capitalization and the quality of its portfolio through options and corporate development activity.



2011 exploration program on the Athabasca Basin with HTEM

Posted by on Thursday, 3 February, 2011

Kirrin Resources Inc.  announced plans for its 2011 exploration program.

The Key Lake Southwest (‘Key Lake SW’) uranium property located on the southeastern margin of the Athabasca Basin in Saskatchewan will attract an estimated budget of $0.7 million. Later this month, Kirrin will commence a 1,400 line km. helicopter-borne time domain electromagnetic geophysical survey. Following the interpretation of results, Kirrin is planning a program of summer fieldwork with the objective of finalizing the selection of drill sites.

The eastern margin of the Athabasca Basin in Saskatchewan, Canada, is home to the most productive uranium mines in the world, with roughly 25% of global uranium production coming from this area. Kirrin’s target at Key Lake SW is basement-hosted unconformity-type uranium, similar to Cameco’s basement-hosted Millennium deposit, located about 50 km to the north-northeast, the Phoenix discovery, located about 60 km northeast, and the former Key Lake mine located about 35 km east-northeast. The review of the technical disclosures regarding the recent Phoenix Discovery has revealed many geological similarities between Phoenix and Key Lake SW.

The interpretation of the recent 1,076 line-kilometre magnetic-electromagnetic (EM) airborne survey revealed 19 anomalies for follow-up, 7 of which are first priority. This follow-up will form the basis of the 2011 drilling campaign. Highway 914, which extends from Lac La Ronge to Key Lake, passes less than 2 km from the eastern edge of the property.

Exploration on March 2010 acquisition commenced in April 2010 with a 1,076 line-kilometre magnetic-electromagnetic (EM) airborne survey. The airborne survey utilised Fugro’s fixed-wing Tempest(r) Digital Time Domain Electromagnetic (DTDEM) system which provides maximum quantitative discrimination of relatively near surface (upper 200 to 300 m) conductivity variations.

Airborne magnetic surveys map the variation in magnetic susceptibility, which predominantly results from changes in the percentage of magnetite and some other magnetic minerals in the bedrock. The magnetic variations thus allow the mapping of differing lithologies, faults, potential alteration zones, etc. DTDEM surveys map the three-dimensional variation in conductivity that is caused by one or more of mineralogy (e.g., conductive minerals such as graphite or sulphides), intensity of alteration, water content or changes in salinity. The correlation of the magnetic responses with the EM conductive trends enables the indirect geological mapping of bedrock under overburden and possible Athabasca Basin sandstone outliers. As well, the airborne geophysical data can identify anomalies and potential geological targets that may be spatially associated with uranium deposits or alteration zones near such deposits.

Following the satisfactory results from December’s geophysical interpretation program at the Grevet REE project in northwestern Quebec, Kirrin is planning a three phase exploration season commencing in late April. The first phase will complete prospecting on priority areas, including the collection of samples and assessment of exploration potential. The second phase will primarily identify drill targets and will commence in July. The third phase, commencing in September-October, will be determined by the compilation and interpretation of the results obtained from the earlier 2011 phases and will likely comprise a 1,500 to 2,500 m drill program in 15 to 25 holes.


Drill testing of AEM anomalies with success

Posted by on Monday, 17 January, 2011

Australian  uranium  company Cauldron Energy Ltd. has completed a reverse circulation (RC) drilling program targeting base metals at the Company’s 80% owned Beadell Project in Western Australia. The  1,702m  drilling  program focused on one of two Tempest AEM targets within the  base metal rich  Rudall Complex of Western Australia.

Interpretation and analysis of the project geology and ground and airborne geophysical data, including ground based gravity, regional magnetic surveys and Tempest  AEM identified two significant conductive zones that are anomalous to the regional geology. The two AEM anomalies, which are linked by a large north trending regional fault system, show features that are consistent with what could be expected from massive sulphide mineralisation.
The recent drilling program comprised a  total  of  six Reverse Circulation (RC) holes for 1,702 metres, targeting the southern “bulls-eye” AEM anomaly. The drilling, on 200m x 100m and 200m x 200m spacings, intersected a dominant high grade amphibolite facies with zones dominated by garnets and epidote as well as common quartz veining associated with broad zones and veins of  disseminated sulphides, predominantly comprised of pyrite and chalcopyrite. A number of weakly graphitic zones were identified within the central part of the drill pattern, which appear to be associated with  north trending  fault zones.  These graphitic zones were often associated with zones of massive pyrite. Drilling along the eastern side of the pattern intersected thin to massive zones of orthogneiss to monzogranite rocks near the base of the drill holes. A number of significant results were returned from the drilling, including individual narrow higher grade zones  of copper and gold associated with  broad zones of anomalous  lead and zinc mineralisation, including  28 metres at  1794 ppm  lead  and 2045 ppm zinc in hole BRDC 003.
Interpretation of the results indicates that the source of the geophysical anomaly identified by the AEM is below the extent of the current drilling and remains to be tested by deeper drilling. Surface geochemical sampling programs and down-hole EM surveys are planned to commence in Q1 2011, to further define the target for follow-up drilling programs.

Airborne Electromagnetic (TEMPEST and VTEM) for uranium in Australia

Posted by on Tuesday, 4 January, 2011

Under Geoscience Australia’s Onshore Energy Security Program (OESP), Airborne Electromagnetic (AEM) data is being acquired in areas considered prospective for unconformity-related and palaeochannel-hosted uranium deposits. The program is aimed at reducing exploration risk and promoting exploration activity.

The surveys, which are part of the Airborne Electromagnetic Acquisition and Interpretation project, are designed to reveal new information about regions by acquiring the AEM data at line spacings of one to six kilometres over relatively large areas. The improved understanding of the regional geology resulting from the surveys will be of considerable benefit to mining and mineral exploration companies, which can obtain more detailed data over a specific area of interest by contributing additional funds to the acquisition cost.

THere are three projects:

Project 1 – Paterson Province, Western Australia

Project 2 – Pine Creek, Northern Territory

Project 3 – Frome Embayment-Murray Basin, South Australia

Complete final data release – Contractor supplied data and Geoscience Australia inversion products:

Paterson TEMPEST AEM Survey, Western Australia, 2010 Complete Final Data
(30 April 2010)

Paterson TEMPEST AEM Survey, Western Australia, 2010 Final Inversion Data and Conductivity Models
(30 April 2010)

Pine Creek TEMPEST AEM Survey, Northern Territory, 2010 Final Inversion Data and Conductivity Models
(30 June 2010)

Pine Creek – Kombolgie VTEM AEM Survey, NT, 2009 Final Data (P1195)
(4 December 2009)

Date of release to be announced



The new Key Lake SW Airborne Survey Results

Posted by on Tuesday, 17 August, 2010

Kirrin Resources Inc. today announced the results of the evaluation and interpretation of the 1,076 line-km magnetic-electromagnetic (Tempest(R) EM) airborne survey of the Key Lake Southwest (‘Key Lake SW’) uranium property located on the southeastern margin of the Athabasca Basin in Saskatchewan. The Condor Consulting Inc. report identified 7 first priority, 5 second priority and 7 third priority targets that warrant follow-up assessment. Some of these anomalies correlate with geological, geophysical or geochemical anomalies identified from prior exploration, whereas others are newly identified. All are prospective for ingress style (i.e., basement hosted) uranium deposits along the geologically favourable Wollaston Group basement trend.

Commenting on the results, Kirrin President and CEO, Derek J Moran said: “These results have added substantial value to the Key Lake SW uranium project, and show clearly its potential for another eastern Athabasca uranium discovery.”

Processing, interpretation and correlation of the results with magnetic response and geology define two main types of conductors, discrete plate-type and broader, flat lying wide zones (Note 1). These have been further grouped by Condor into 19 target zones and subjectively ranked, according to their conductivity, magnetic association, strike extent and geological association, from high to low priority, with 7 target zones being ranked first priority. Historic wide-spaced drilling on parts of four of the 19 target zones identified prospective geology, including a possible sub-Athabasca Group regolith that was logged in several holes which are located within a Wide Zone EM conductor.

The number one priority target zone has good potential for uranium mineralization because significant uranium values within wide zones of graphitic pelites have been intersected in drill holes targeted along the northeastern extension of this conductor lying within Triex’s Riverlake and Forum Uranium’s Orchid properties. There are 9 other target zones (for a strike length of 52.9 km) which display similar geological and geophysical conductive and magnetic characteristics as observed on adjoining properties and over other uranium deposits in the region and thus are ranked as having high potential for uranium mineralization. The survey also showed that some target zones at Key Lake SW have potential for base metal mineralization or iron formation similar to the geological horizons mapped in the McArthur River mine.

Kirrin is planning the next stage of exploration at Key Lake SW. Follow-up fieldwork at selected first priority targets is likely to comprise (a) systematic prospecting of anomalous conductive trends to prioritise drill targets along those trends, (b) follow-up geochemical lake sediment and possibly soil surveys, (c) magnetic and electro-magnetic surveys on grid areas established over first priority target zones in order to locate conductive axes and attitudes for drill collar positioning, and (d) drill testing of selected targets.

Note1: Magnetic surveys, structural geology, drill and surface geochemistry compiled over the eastern portion of the Athabasca Basin indicate that uranium enrichment and deposits are associated with conductive horizons, located within or along magnetic low troughs, which typically represent graphitic and sometimes magnetite rich iron formations and associated contacts. These horizons are flanked or sandwiched between magnetic highs, which represent underlying Archean type granitoid domes or arches. The reduced magnetism is caused by regional faults, which provide control and form traps for uranium enrichment. The graphitic rich pelite horizons in the basement rock are excellent conductors and host uranium mineralization. They act as markers as they can be located with electromagnetic surveys and targeted with drill holes.