|
|
Norsk versjon | ||||
| THE ORE DATABASE | |||||
| Deposit Area 1219 - 003 | |||||
| (Last updated 18.aug.2020) | |||||
Name of Deposit Area : Bømlo |
| (Object Id : 1219,003,00,00) |
| Location |
| County : | Hordaland (12) | Municipality : | Bømlo (1219) |
| Map 1:50000: | Bømlo (1114-2) | Map 1:250000: | Haugesund |
| Marking point: | Longitude: | 5.1766990 | Latitude: | 59.7127630 |
| EU89-UTM Zone 32 |
| X-coord: | 284977 m. | Y-coord: | 6625621 m. |
|
|
| Commodity |
| Main Type: | Precious metals (Au,Ag,PGE) | Sub Type: | Gold | |
| Element(s): | Au |
| Production |
| Activity: | Test mining | Reserves: | ||
| Prod. method: | Open pit and underground mining | Production: | ,1 thousand tons | |
| Prod. status: | Volume of dump: | 40 m3 |
| Importance |
| Public: | Little Importance (reg. 26.05.2015) |
| Economical: | Not classified/evaluated |
Operations |
| From - To | Activity | Comments | |
| 1883 - 1898 | Test mining | ||
| 1991 - 1991 | Sampling |
Mineralization |
| Era: | Period: | |||
| Dating: | Method: | |||
| Genesis: | Hydrothermal vein | Form: | Plate | |
| Main texture: | Vein network | Min. distribution: | Disseminated (<20 % ore minerals) |
| Main grain size: | Fine grained (< 1 mm) | Main alteration: | Pyritisation |
| Strike/Dip: | 20 / 90 | Direction: | ||
| Plunge: |
| Stratigraphic classification of host rock |
| Era: | Period: |
| Province: | Caledonides | |
| Geotec.unit: | Hardangerfjord Nappe Complex | |
| Tectonic complex: | ||
| Igneous complex: | Lykling Ophiolite Complex |
| Group: | Formation: |
Mineralogy |
| Relationship | Mineral | Amount | |
| Gangue mineral | Quartz | Major mineral (>10%) | |
| Gangue mineral | Carbonate | Major mineral (>10%) | |
| Gangue mineral | Chlorite | Major mineral (>10%) | |
| Ore mineral | Pyrite | Major mineral (>10%) | |
| Ore mineral | Gold | Accessory mineral (<1%) |
Lithology: |
| Relationship | Rock | Origin | |
| Wall rock | Gabbro | Intrusive Original rock :Gabbro |
|
| 535 (-46\+46) mill. years;..Method:Rb/Sr |
Structures |
| Location: | Type: | Orientation(360 gr.): | Relation to min.: | |
| Unknown | Shear plane | Strike/Dip :20 / 90 | Syn-mineralisation ;...Effect :Controls |
Information(s) in free text format |
| Free text |
| The Bømlo deposits are mesothermal gold-bearing quartz veins in shear zones in the Lykling ophiolite complex, frequently following the contacts of dolerite dykes. The veins and their chloritised and carbonatised wallrocks are characterized by the presence of coarse-grained native gold, giving spectacular hand specimens that are extracted today. Analyses of bulk samples are normally in the range of 2–5 g/t Au. A few, minor Cu-Zn and Fe-sulphide (‘vasskis’) occurrences are related to metabasalts and felsic metavolcanic rocks overlying the ophiolite complex |
Bibliography: |
| From NGU's Reference Archive: |
| Wulff, P.; Stendal, H. , 1995 |
| Gold in Sunnhordland, the caledonides of southwestern Norway. [Abstract] |
| ;Grønlands geologiske undersøgelse;ARTIKKEL;Open file series; Gold mineralization in the Nordic countries and Greenland. Extended; abstracts; No.95/10;116-119 pages |
| Abstract: | |
| Conclusion The Palaeozoic supracrustal rocks of the Sunnhordland area is an important metallogenic zone with gold-bearing quartz veins and massive sulfide mineralization especially Cu and Zn associated with Au and Ag. The gold mineralization in most of the quartz veins is of the mesothermal type. Wulff (1993) and Christensen (1994) concluded that most quartz veins on Bømlo are spatially related to the Sunnhordland Fault Zone (SFZ) or the Hardangerfjord Fault Zone (HFZ). The quartz veins at Vernøy and Hovdaneset is situated not far from SFZ or HFZ thus indicating a relationship. In summary this study has shown that far from all interesting mineralization has been found in the highly prospective Sunnhordland area. The most prospective areas is considered to be along SFZ and HFZ. |
| Wulff, Peter Wilhelm , 1996 |
| En befaring af cirka 100 mineraliseringer i Sunnhordland, SV-Norge |
| ;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.96.139;100 pages |
| Abstract: | |
| Forfatteren var sommeren 1994 engasjert av NGU for å gjøre et arbeid i Sunn- hordland i forbindelse med planlagt utgivelse av en publikasjon om Norges gullforekomster. Samtidig kunne Malmdatabasen gjøres ferdig for dette området. Rapporten beskriver resultatene av malmregistrering i Sunnhordland som om- fatter ca. 100 mineraliseringer. Disse er koordinatfestet og geologisk beskrevet. I tillegg er det gitt gruvehistoriske kommentarer av forekomstene og referanser. Resultatene fra denne rapport er innlagt i NGUs Malmdatabase. Rapporten gis av praktiske grunner ut i dansk språkform som den foreligger fra forfatter. |
| Ihlen, Peter M. , 1999 |
| Gold deposits in Norway - a review |
| ;NGU/UBIT;ARTIKKEL;Gold '99;96-98 pages |
| Sandstad, J.S. ; Bjerkgård, T. ; Boyd, R. ; Ihlen, P. ; Korneliussen, A. ; Nilsson, L.P. ; Often, M. ; Eilu, P. ; Hallberg, A. , 2012 |
| Metallogenic areas in Norway |
| ;Geological Survey of Finland;ARTIKKEL;Special paper; No.53;35-138 pages |
| Abstract: | |
| There are 40 major metallogenic areas within the Norwegian part of the Fennoscandian shield. Of these, 12 areas show potential dominantly for copper, zinc and lead, 11 for ferrous metals (Fe, Ti, V), 9 for nickel and cobalt, 5 for precious metals (Ag, Au) and 3 for molybdenum. A large number of major genetic types of metal deposits are known from Norway. By past production and present resources, the most significant deposits and areas include: mafic, intrusion-hosted Ti-Fe+-V (Tellnes), VMS (Løkken, Folldal, Røros, Grong, Mofjell, Sulitjelma), sedimentary Fe (Rana, Sør-Varanger), sediment-hosted Cu (Repparfjord, Nussir), ortho-magmatic Ni+-Cu (Råna) and porphyry Mo (Nordli). Most of the known metallic mineral deposition in Norway were formed during the Caledonian rifting to subduction and collision, during 600-390 Ma (VMS in several districts, sedimentary Fe, orthomagmatic Ni-Cu, metamorphic Ti). Other major metallogenic events include Neoarchaean, 2900-2800 Ma (BIF), Palaeoproterozoic 2400-1800 Ma (sediment-hosted Cu, orogenic Au, Cu), Sveconorwegian, 1200-900 Ma (mafic-intrusion hosted Ti-Fe) and the Oslo Rift, 300-240 Ma (porphyry Mo). |
| The fact sheet was created on 19.05.2024 |
| Questions or comments regarding the fact sheet can be emailed to: ressursdatabaser@ngu.no |
| Copyright © 2024 Geological Survey of Norway |