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Bergvesenet 2 Postboks 3021, 7002 Trondbeim Rapportarkivet Bergvesenet rapport nr Intern Journal nr Internt arkiv nr Rappon lokalisering Gradering BV 862 388/81 FB T& F4B6 Trondhcim Fertroli,g _ e Kommer fra ..arkiv Ekstern rapport nr Oversendt tra Fortrolig pga Fortrolig fra dato: Troms & Finnmark Sydv 1147 Tittel Diamond drilling program on target area no. 11 and sample cirilling in Karasjok area Forfatter Dato Bedrift Røsholt, Bernt 03.111980 Sydvaranger A/S Kommune Fylke Bergdistrikt 1:50 000 kartblad 1: 250 000 kartblad Karasjok Finnmark Troms og Finnmark Fagornråde 1 Dokument type Forekomster Geologi Geokjemi Geofysikk Boring Råstofftype Emneord Sammendrag Rapporten inneholder også en rapport ang. 'Target area II - Finnmark, Sept. 19/80. Magnetics and self potential survey" av Steve Medd. KONFIDems ;at />73----e/ Repvef viö11(17- A/f. 1,‘ b • DIAMONIDRILLINGPROGRAMON TARGET AREA NO. 11 AND SAMPLE DRILLINGIN KARASJOKAREA. GEOLOGY. In 1979 an ultramaficbody was found in the Addjatavziarea 20 km NNE of Karasjok.The body has a NS and NV-SE strikewith a maximum size of 1,8 x 0,4 km. It dips 40 to 60° to the east. Due to a rather high magnetitecontentinparts of the ultramaficbody the bouncry- of the ultramaficbody LSpartly determinedfrom magneticground measurements.Geologicalmapping in the area is rather difficult because of heavy overburden.The ultramaficsjhoweverlareresistant againstweatheringso the centralpart of it is rather well exposed. The outlinesof the ultranaficbody can be seen on the e.:closedSP- map. The ultramaficconsistsof 89-92 % serpentinein 0,5-2mm srains, 10-20 % of Mg - Chlorite (Penninite)and a little carbonate.A whole rock analysesof a sarr,p18fr=the 'f_tranaficbcdyshcws the fc11:w- inz composition: 5i02 37,4% Mn0 0,18 % 1(20 not detected 0,04 % Ti02 0,35 Mg030,92 % P2°5 Al2 CaD 2,52 % CO2 % Fe203 tot. 11,4 % Na20 0,04 % Jgricss 10,43 % Ore minerals : Pentlanditeand chalcopyriteare found in sanples from the ultramaficbody, but only as traces.Large bolderswith pyrrho- tite banded with amphibolesare found. Analysesfrom these shows no Nickel and Copper contents. Amphibolitesometimeswith garnets and bands of felsicgneiss sur- rounds the ultramaficbody. Chloritercck (greenstone?) is found both in the amphiboliteand in the ultramaficbody. Two small areas with gabbro are found. Traces cf malachiteis found in the southernpart of the ultranafic body. In the very SE part of the area by the sharp bend of the creek it is found a very bleachedrock which is believed to te an alteredgneiss. Bleachedrocks similar to the type being found often are seen near NtSU Reg Det: a a n 741 677 197 1771 2236 — 1978 1564 X _ _ _ 540 1122 - - Nattvann SN — — — — 1976 6 -13 - - - - - - - - 12P- 2700 0 Karasp 2 Sum: JiesjOkka d2 Reg: Det: 7316 40 35 10km 11.351 .0 KEY: L7L- ti Helicopter measurements 1980: 27 30pkrn Helicopter measurements 1979 : 2200pkm { Soi1 sampled areo in the rocks of the Korasjok Group 1976 -1980 Basement Anomalous areas fl ?Raitevarre Fig 1 - 2 - massive sulphidedeposits. GEOCHEMISTRY. Two enclosedtransparentmaps show the highestCu-Ni and Zn-Pb soil anomaliesfrom the area. Soil sampleswere first taken in 1979 with sample distance50 m and a spacingof 250 m betweenthe lines. This sunmer additionalsoil sampleswere taken with sample distance 25 and 12,5 m over the Sp-anomaliesfrom the first recognitional ground measurements.Especiallythe southernpart of the ultramafic body gives a rather high Ni and Cu ananalyin the soils with con- tents of 400 ppm Ni and 400 ppm Cu ås the highest. Very few Zn and Pb anomaliesshowed up which alsoweresupected. It - was however a combinedZn-Pb anomaly in the SE part of the area over the highestSp-anomaly.A Pb and Cu-anomalyshows up in the very SE-part of the area by the sharp bend of the creek over the outcropS of the bleachedgneissicrocks. One Zn-Pb ananaly can also be seen in the southernpart of the ultramaficbody. Concerningthe lead anomalies,it should be mentionedthat lead is . a rather common accessorv element in Cu-Ni-oresderivedfrom ultra- mafic magmas. The lead-telluridealtaite is found as an accessoricmineral in the Gallujaureprospect8 kms to the west. It alsc should be menticned that lead is a very mobile element in ore formingmagmas and it often forms coronasaround massive sulphidedeposits. GEOPHYSICS. Recognitionalground geophysicswas carriedout early in the 1980- season.It was measuredSP, Mag., VLF and resistivity.Later the same season a base line was staked and the area was coveredby SP and mag. measurements.The resultsfrom thesemeasurementscan be seen on the enclosedSP and mag. map. The highestmeasuredmagneticvalues are + 40 000K and - 18 000d and the SP values lies between + 152 mV and - 879 mV. Lookingupon the magnetic ancmaliesit is quite clear that they are caused by the contentof magneticminerals in the ultramaficbody. This is very clear over the main N-S-strikingbody, but can also be seen over the scatteredultramaficoutcrops to the NW. It is be- lieved to be some magnetitein the pyrrhotitebolders found in the area. Magnetitealso is found concentratedin the ultramaficbody in certain zones. The resultsfrom the SP-measurementsrevseal 4 anomalies.In the SW part of the area . the SP-anomalyis coincidin= with the mag. anomaly.To the east of the ultramaficbody is the largestSP-anomaly.A small magnetic anomaly (1000() is also coincidingwith this. To the NW it is a long SP-anomalyparallell to the mag.-anomalywith a spacingto the west of 100-150m. This anomaly seems to continueto the NW, and possiblya little to the SE. Next summer additionalmeasurementswill be carriedout both on this anomaly and also on the anomalyto the NE. To the east, rather high positiveSP-anomaliesenvelopsthe area. This should confirm that the conductingzones are dippingto the east. The VLF and resistivityrecognitionalmeasurementsalso came up with good coincidinganomalieswith the SP-anomalies.Especially over the ultramaficbody in the southernpart of the area W of the proposeddrillholeno. 1 resistivitiesof only 1-50 ohmm were measured over 170 m. CONCLUSIONAND PROPOSALS. It shculd be stated that all electricconductorsin the ground inside and in the vicinityof ultramaficbodies ought somehowto be checked.The best way would be diamond core drilling,but per- curssiondrillingthroughthe overburdendirectlyon the ancmalies also is possible. The fact that we have found large bolderswith pyrrhotiteand vein- lets of magmaticpyrrhotitein the outcroppingserpentinitesover the EM-anomaliesis encouragingand should lead to diamonddrilling. In the famous and most importantSoviet Cu-Ni-depositsin the Petsamoarea 200 km's to the east barren pyrrhotiteis described closelyrelatedto the economicdeposits. From "Ore depositsof the USSR Vol II" edited by V.I. Smirnov, 1977 (PitmanPublishing)the followingshould be referredfrom the Kaula depositin the Petsamoarea : "As the tectoniczone passes into the phyllites,there is a gra- dual decreasein the thicknessof the uniform,breccia-like,and accompanyingmineralizedcountry rocks, and also a decreasein the amount of nickel and copper to the point of completereplacement of the normal copper-nickelores by purely pyrrhotitictypes. The zone of pyrrhotitemineralizationcan be traced to a depth of 8o0 m from the surface". SP •10OrnV Mag SP 0 \ / -100 \ \ i Mag SP — - N i - 100002( 1 \ -100my / 500 \ 1 / t 1 P. i t -200 t / t I - 500 0 1 / I I I i Mag 0 / 1 I I I 1 t I -300 1 -filoot) I 1 I ICOOg tI 1 -800 -500 1 2 B A \ 45. \ Pack- sack drillhole ". 70-90. 45. Scale \ 150m 100m Scale 150m 93 100en t 004 \ Section of prced drillholes 1A and 18 Section of proposed &illhole no 2 200m7, Oneiss \ Ultramafic rocks DRILLHOLENO 1 A AND 1 B. The figure of the proposeddrillhole1 A and 1 B also shows the mag. and SP-anomalies.Resistivitymeasurementsover the proposed area showed resistivitiesas low as 1-50 ohmm from the drillhole and 170 m towards the west. It is proposedtwo holes 1 A and 1 B here to get precise informationof the dip of the mineralization and ultramaficbody. The possibledifferenceof metal contentin these two sectionsalso will give informationof increaseor de- crease of metal contenttowards the depth to the east. A pack-sackdrillholein serpentiniteto a depth of 3,6 m in the anomaleousarea near the proposeddrillholeone had two sections of 1-2 cm's of magmatic pyrrhotiteand some traces of chalcopyrite. DRILLHOLENO 2. This hole should also be drilled because of the very high SP- anomalies,see figure. The SP-anamaliesare so high that Iheg Arc possibly caused by black shists. On the other hand it is not likely to believe that it is black shists because the strike onLy is 450 m. Nearly coincidingwith the SP-anomalyit also is a smallmag. anoma- ly - 250 to + 900 gamma4 Soil sample ånomaliesof Cu, Ni, Pt and Zn are also concidinG with the SP-anomalies. Approximately100m to the south of drillholeno 2 the outcropsof the mentionedbleachedrocks are found. If the ultramaficbody is dipping in the order of 45° to the east it is possibleto reach it by extendingdrillholeno 2. Another diamonddrillingproposalshould be set up for extendinghole no 2 in case the liolesfromno 1 are encouragingpositive. DRILLHOLDNO 3 AlD 4 should not be core-drilledin case the results from the no 1 and 2-holesare very negative.Even weak positiveresultsfrom hole no 1 and 2 should lead to drillingof holes no 3 and 4. No 3 and 4 will be together200 m. In area no 11 we are in a very importantultramafic-greenstone- belt which can be followedapproximately15 km's to the north. By having as much basic knowledgeas possiblefrom target area no 11 it will be easier to evaluatethe whcle belt. Mag SP 800 Mag 800 5P / 0p‘ mV ..-A SP % \ I )31 SP 0 mV I I / I \ / I—N \ 1 4 / i \ -100 I I \ / X -100 fi 1 1 I I \ A \ \ / / ‘.. I I I \ I -20C \ i I I - 200 /1 %I 1 X /Mag 1 / i v ." ..." 0 \ / 0 .