(Last updated: 07.03.2017)
|
|
Norsk versjon | ||||
| THE ???? DATABASE | |||||
| Occurence 0 - 000 FEIL | |||||
| (Object Id: ) (Last updated: 07.03.2017) |
|||||
|
|
| Location |
| County: | Municipality: | Mangler () |
| Map 1:50000: | Takvatnet (1533-3) | Map 1:250000: | Tromsø |
| County: | UTM-Zone 33 - EUREF89/WGS84 |
|
|
| Resource |
| Resource Type: | Ferrous metals(Fe, Mn, Ti) | Resource Subtype: | Iron | |
| Element(s): | Fe |
| Importance |
| Raw material meaning: | Little Importance (reg. 02.06.2015) |
| Resources and production |
| Activity: | Exploration | Reserves: | ||
| Operating method: | Historical production: |
Operations |
| From - To | Activity | Comments | |
| 2011 - 2011 | Geophysics | Company/Institution :NGU | |
| Aerial survey (mag., EM, radiometry) | |||
| 2011 - 2013 | Geology | Company/Institution :NGU |
Mineralization |
| Era: | Proterozoic | Period: | Mesoproterozoic | |
| Genesis: | Chemical sediment | Form: | Lens | |
| Main texture: | Banded | Min. distribution: | Semi-massive (20-50 % ore minerals) |
| Main grain size: | Medium grained (1-3 mm) | Main alteration: | No country rock alteration |
| Strike/Dip: | Direction: | |||
| Plunge: |
| Stratigraphic classification of host rock |
| Era: | Proterozoic | Period: | Mesoproterozoic |
| Province: | Troms-Finnmark Basement Province | |
| Geotec.unit: | ||
| Tectonic complex: | Mauken Tectoni Window | |
| Igneous complex: |
| Group: | Målselva Group | Formation: | Myrefjellet Formation |
Mineralogy |
| Relationship | Mineral | Amount | |
| Gangue mineral | Carbonate | Major mineral (>10%) | |
| Gangue mineral | Grunerite | Major mineral (>10%) | |
| Gangue mineral | Quartz | Major mineral (>10%) | |
| Gangue mineral | Biotite | Subordinate mineral (1-10%) | |
| Gangue mineral | Chlorite | Accessory mineral (<1%) | |
| Ore mineral | Magnetite | Major mineral (>10%) | |
| Ore mineral | Pyrite | Accessory mineral (<1%) |
Lithology: |
| Relationship | Rock | Origin | |
| Wall rock | Greenschist/tuffite | Sedimentary Original rock :Tuffite |
|
| Metamorphic facies :Greenschist | |||
| Wall rock | Greenstone | Extrusive Original rock :Basalt |
|
| Metamorphic facies :Greenschist |
Information(s) in free text format |
| Free text |
| The iron formation is exposed in the pronounced Bjelma valley to the west of Myrefjellet. This valley (with the Bjelma stream), marks the boundary between the banded, tuffitic greenschist and the generally massive greenstone/ metabasalt. It gives a well-defined magnetic anomaly. The iron formation is located in the northwestern part of this valley, in the extension of a layer of calc-brecciated greenstone. It has a length of at least 700 m and a thickness of up to 30 m close to the major bend of the Bjelma stream. The iron formation varies in composition across strike, from quartz- to carbonate-rich. The carbonate is generally a brown, Fe-rich calcite or ankerite. Fine-grained magnetite is present in thin bands throughout the formation, generally the thin bands are found in zones less than one meter in thickness. Some zones in the formation are enriched in sulfides, mainly pyrite. One sample analyzed of the carbonate-rich part contains 25.5 % Fe2O3, 0.07 % TiO2 and 0.18 % P2O5, and one quartz-rich sample contains 33.0 % Fe2O3, 0.03 % TiO2 and 0.14 % P2O5. A 5-20 m thick layer of banded to laminated schist quite strongly enriched in magnetite is present in the banded greenschist some meters from the boundary to the greenstone. The unit contains bands with 2-4 % magnetite (measurements by handheld susceptibility meter. The unit can be followed for more than 1 km along strike. It is possible that this unit somehow is related to the iron formation. |
Bibliography: |
| From NGU's Reference Archive: |
| Bjerkgård, Terje; Henderson, Iain; Sandstad, Jan Sverre; Schönenberger, Johannes; Slagstad, Trond , 2015 |
| Geology of the Mauken tectonic window, Målselv, Troms |
| ;Norges geologiske undersøkelse;RAPPORT;NGU-rapport; No.2015.013;60+kart pages |
| Abstract: | |
| This report presents the results from bedrock mapping in the Mauken tectonic window, carried out in several periods in 2011-2013. During the NGU MINN program, the Mauken area has been subject to a high-resolution airborne geophysical survey (magnetometry, radiometry, EM), followed by bedrock mapping and structural geology investigations. The work in the Mauken area is part of a larger project in southern Troms, with the goal to work out a structural-tectonic-metallogenic model and interpretaion for the basement areas in the whole region. |
Fieldsamples |
| Sample No. | Sample type | Miscellanrous | ||||
| TBMA_5 | Bedrock |
|
||||
| TBMA_72 | Bedrock |
|
| NB! All analyse values are shown at the end of the printout.: |
| The fact sheet was created on 29.04.2024 |
Copyright © 2024 Geological Survey of Norway |