Core drilling at Gjedde Lake and regional structural geological investigations in Pasvik, Sør-Varanger kommune, Finnmark 1996.
Bedrift NGU, KENOR AS
- Geografi
- Sør-Varanger
- Geometri
- Geometri ikke oppgitt
- Publisert
- Kildestatus
- Publisert
Eksakte kildefelt
Fraværende valgfrie felt blir ikke erstattet med dekorasjon eller antakelser.
- Rapportnummer
- BV4588
- Register
- Undersøkelsesrapporter
- Status hos DMF
- Publisert
- Mottatt
- Forfatter
- Ihlen, Peter Often, Morten Braathen, Alvar
- Bedrift
- NGU, KENOR AS
- Kommune
- Sør-Varanger
- Fylke
- Finnmark
- Sammendrag
- The report gives a preliminary assessment of the core drilling carried out on the Gjedde Lake gold mineralizationiuring the summer 1996. 12 holes with a total length of 600m was drilled. The core drilling revealed that the outcrops of auriferous grunerite quartzite (BBQ) at the discovery point actually represent ice-transported blocks. This is also the case for other previously registered outcrops in the Gjedde Lake area. The source of the auriferous blocks was located, 25m to the southeast, below 2-6m of till. Gold-bearing BBQ was first intersected in the second drillhole (DDH 2) and was subsequently also found in DDH 3, 6, 7, 9, 10 and 11. It defines an isoclinal fold which is overturned towards the west and plunging south, 188°/40°. The thickness of the BBQ along the limbs is about 1.0 m and increases to about 5.0 m in the hinge zone where it is cut by abundant arsenopyritequartz veins also extending into the wall rocks. The contact of the BBQ is highly strained and it contains up to 15 g/t Au in DDH 2 where Fe-sulphides are enriched as 1-2 cm wide bands. The BBQ is surrounded by retrograded and strongly sheared mafic schists, i. e. hornblende-biotite-chlorite schists with abundant generations of carbonate-quartz yeins and schlieren. The mafic schists or mylonites strike E-W and dip about 40° south. They represent pervasively altered and sheared fine-grCuned amphibolites which can be found as narrow, chlorite-altered zones, locally with garnet. They normally contain dissemination of pyrrhotite, pyrite and minor chalcopyrite rarely exceeding I % in volum. Rich pyrrhotite mineralization is also locally present in a graphite schist unit occurring about 20 m structurally below the lower limb of the BBQ. The mafic schists and the BBQ-zone are part of a regional thrust or shear zone which evolved during up-thrusting of the Archean gneisses to the west and south. It can be tentatively followed from the South Pechenga Block in Russia via Pasvik and northwestwards to Polmak and Tana River. It represents, therefore, an important 1. order structure which acted as a conduit for large scale fluid migration through the crust. This further suggests the possible existence of other gold mineralization along 2. and 3. order structures adjacent to it which are typically encountered in auriferous greenstone belts on a global scale. Further follow-up is, therefore, recommended, including top-soil and till geochemical surveys.
- Rapport hos DMF
- Åpne rapport
KILDEFAKTUM
Direktoratet for mineralforvaltning
Objektet kommer fra datasettet «Undersøkelsesrapporter» og vises med kildegeometrien uendret i betydning.
TOLKNINGSGRENSE
Hva objektet ikke dokumenterer
Oppføringen dokumenterer at DMF har publisert rapportmetadata. Kartet viser DMFs egne rapportpunkter, ikke rapportens fulle undersøkelsesområde. Mineralradar tolker ikke PDF-innholdet og utleder ikke ny aktivitet, funn, reserve, kvalitet eller økonomisk potensial fra rapporten.
Regulatorisk kronologi
Kildedato og Radar-observasjon beholdes som ulike tidssemantikker.
Ingen senere endringer observert
Objektets nåtilstand er tilgjengelig, men historikken inneholder ingen hendelser etter baseline.