(Last updated: 18.06.2001)
|
|
Norsk versjon | ||||
| THE ORE DATABASE | |||||
| Occurence 4211 - 010 Vekselmyr | |||||
| (Object Id: 5290) (Last updated: 18.06.2001) |
|||||
|
|
| Location |
| County: | Agder | Municipality: | Gjerstad (4211) |
| Map 1:50000: | Gjerstad (1612-1) | Map 1:250000: | Arendal |
| Coordinate system: | EU89-UTM Zone 32 |
| East: | 502280 m. | North: | 6523199 m. |
| Longitude: | 9.0395120 | Latitude: | 58.8486500 |
| Show on map |
|
|
| Resource |
| Resource Type: | Precious metals (Au,Ag,PGE) | Resource Subtype: | Gold | |
| Element(s): | Au As Cu |
| Importance |
| Raw material meaning: | Little Importance (reg. 18.02.2015) |
| Resources and production |
| Activity: | Pitting | Reserves: | ||
| Operating method: | Historical production: |
Operations |
| From - To | Activity | Comments | |
| 1984 - 1984 | Geology | Company/Institution :ARCO | |
| 1984 - 1984 | Geochemistry | Company/Institution :ARCO | |
| 2000 - 2000 | Sampling | Company/Institution :NGU |
Mineralization |
| Era: | Proterozoic | Period: | Mesoproterozoic | |
| Genesis: | Hydrothermal vein | Form: | Lens | |
| Main texture: | Fracture filling | Min. distribution: | Disseminated (<20 % ore minerals) |
| Main grain size: | Medium grained (1-3 mm) | Main alteration: | Sericitisation |
| Strike/Dip: | 60 / 60 | Direction: | ||
| Plunge: |
| Stratigraphic classification of host rock |
| Era: | Proterozoic | Period: | Mesoproterozoic |
| Province: | South Norwegian Basement Province | |
| Geotec.unit: | Bamble Complex | |
| Tectonic complex: | ||
| Igneous complex: |
| Group: | Formation: |
Mineralogy |
| Relationship | Mineral | Amount | |
| Gangue mineral | Quartz | Major mineral (>10%) | |
| Gangue mineral | Feldspar | Subordinate mineral (1-10%) | |
| Ore mineral | Arsenopyrite | Major mineral (>10%) | |
| Ore mineral | Pyrite | Major mineral (>10%) | |
| Ore mineral | Chalcopyrite | Subordinate mineral (1-10%) |
Lithology: |
| Relationship | Rock | Origin | |
| Wall rock | Amphibolite | Extrusive Original rock :Basalt |
|
| Metamorphic facies :Amphibolite |
Structures |
| Location: | Type: | Orientation(360 gr.): | Relation to min.: | |
| Wall rock | Foliation | Strike/Dip :55 / 65 | Pre-mineralisation ;...Effect :None | |
| Wall rock | Schistosity | Strike/Dip :58 / 55 | Syn-mineralisation ;...Effect :Modifies |
Information(s) in free text format |
| Free text |
| Skjerpet ligger 1 km sørvest for Byholt på sørsida av Gjerstadvatnet. Det består av en liten, 1 x 2 m, utsprengt grunn grop og avrøsket fjell i en lengde av ca. 12 m og med bredde opptil 4 m. Røskingsarbeidene ble utført av ARCO Norway Inc. i 1984. Mindre røskegrøfter på tvers av strøket er nå knapt synlige. En opptil 0,5 m bred kvartsgang med retning 60°/60° kan følges i amfibolitt i hele røskens lengde. Gangen skjærer foliasjonen i amfibolitten (55°/65°) med liten vinkel. Sulfidmineralene utgjør opptil 50 % av gangmassen og består i hovedsak av arsenkis og pyritt med spor av kobberkis og opptrer som aggregater og smale bånd (prøve .01). Kvarts, feltspat med laminer av kloritt og glimmer er gangmineralene. Amfibolitten er dels serisittisert og silfisert med svak sulfidmineralisering rundt gangen (prøve .02). I tillegg finnes mindre umineraliserte slirer og årer med kvarts±granat i denne. |
| Photo(s) from the Deposit area: |
|
Bibliography: |
| From NGU's Reference Archive: |
| Grahl-Madsen, Laila; Bech, Lone , 1984 |
| Exploration in the Espelandsmyr-Gjerstad area, 1984 |
| ;Norges geologiske undersøkelse;RAPPORT;Bergarkivet; No.BA 7970;38 + kart pages |
| Abstract: | |
| Også som ARCO report, no. 84-23-38 i NGU Dagbokarkivet. The Espelandsmyr-Gjerstad area is part of the Proterozoic Bamble belt. The rocks are in amphibolite or locally granulite metamorphic facies. The orientation of rocks is northeast-southwest with a steep southeast dip. Uncertain facing evidences indicate younging towards the east. The Espelandsmyr-Gjerstad area comprises a mixed volcanic-sedimentary rock package with exhalative features and a few younger granitic and gabbroic intrusives. The mineral occurrences in the area include: a) a stratabound Pb-Zn-Ag massive sulfide deposit of exhalative origin b) stratabound graphite and disseminated Fe-(Cu)-sulfides c) an epigenic As-Au-Cu vein deposit. None of the explored mineral occurrences has been og economic size or grade. The area still has a potential for both epigenetic and stratabound Au deposits. |
Fieldsamples |
| Sample No. | Sample type | Miscellanrous | ||||
| AA0118.01 | Bedrock |
|
||||
| AA0118.02 | Bedrock |
|
| NB! All analyse values are shown at the end of the printout.: |
Analyse Results |
| from |
| Deposit Area 4211 - 010 Vekselmyr |
Element analyses |
( *=parts pr. million, #=parts pr.billion, Negative values means below detection limit value.) |
| Sample No. | Sample Type | Cu* | Zn* | Pb* | Co* | Ni* | Ag* | Au# |
| AA0118.01 | Bedrock | 881 | 29 | 14 | 1140 | 199 | 1.4 | 5925.0 |
| AA0118.02 | Bedrock | 309 | 33 | 2 | 27 | 38 | .2 | 40.0 |
| ------------------ |
| Sample No. | Pt# | Pd# | As* | Cd* | Ba* | Mo* | Sb* | Bi* | S% |
| AA0118.01 | 1.0 | 1.0 | 99999 | .8 | 29 | 6.00 | 9 | 8 | 10.70 |
| AA0118.02 | 1.0 | 2.0 | 744 | .1 | 48 | 6.00 | 2 | 2 | 1.84 |
| ------------------ |
| Sample No. | V* | Cr* | Mn* | Fe% | Th* | U* | W* | Sr* | La* |
| AA0118.01 | 188 | 75 | 101 | 23.23 | 3.00 | 26.00 | 8 | 8.0 | 7.00 |
| AA0118.02 | 123 | 86 | 189 | 6.17 | 3.00 | 4.00 | 1 | 9.0 | 10.00 |
| ------------------ |
| Sample No. | B* | ||||||||
| AA0118.01 | 22 | ||||||||
| AA0118.02 | 2 |
| The fact sheet was created on 28.04.2024 |
| Questions or comments regarding the fact sheet can be emailed to: ressursdatabaser@ngu.no |
| Copyright © 2024 Geological Survey of Norway |