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	THE ???? DATABASE
	Occurence 0 - 000 FEIL
	(Object Id: ) (Last updated: 29.02.2024)

Products

	Element/product	Crude ore grade or quality	Reg. date
	Au	10 g/t	06.11.2001

Operations

	From - To	Activity	Comments
	1770 - 1783	Test mining	Company/Institution :Kongsberg Sølvverk
	1792 - 1807	Regular production	Company/Institution :Bernt Anker
	1896 - 1907	Regular production	Company/Institution :Golden Mint Mines, Ltd
	1983 - 1983	Geophysics	Company/Institution :Norsk Hydro a.s.
	1983 - 1984	Sampling	Company/Institution :Norsk Hydro a.s.
	1983 - 1984	Detail mapping	Company/Institution :Norsk Hydro a.s.
	1987 - 1988	Core drilling	Company/Institution :Folldal Verk A.S.
	1991 - 1993	Geophysics	Company/Institution :NGU-Hedmark Gruvedrift a.s.
	1992 - 1995	Pitting	Company/Institution :Hedmark Gruvedrift a.s.

Mineralization

	Era:	Proterozoic	Period:	Neoproterozoic
	Dating:	776 (-8\+8) million year	Method:	K/Ar
	Genesis:	Hydrothermal vein	Form:	Plate
	Main texture:	Fracture filling	Min. distribution:	Disseminated (<20 % ore minerals)

Main grain size:

Medium grained (1-3 mm)

Main alteration:

Sericitisation

	Strike/Dip:	270 / 75	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Paleoproterozoic

	Province:	East Norwegian Basement Province
	Geotec.unit:	Solør Complex
	Tectonic complex:	Mylonite Zone
	Igneous complex:

Group:

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Chlorite	Major mineral (>10%)
	Gangue mineral	Calcite	Subordinate mineral (1-10%)
	Ore mineral	Chalcopyrite	Major mineral (>10%)
	Ore mineral	Pyrite	Major mineral (>10%)
	Ore mineral	Hematite	Subordinate mineral (1-10%)
	Ore mineral	Galena	Subordinate mineral (1-10%)
	Ore mineral	Magnetite	Accessory mineral (<1%)
	Ore mineral	Bornite	Accessory mineral (<1%)
	Ore mineral	Carrollite	Accessory mineral (<1%)
	Ore mineral	Sphalerite	Accessory mineral (<1%)
	Ore mineral	Gold	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Augen gneiss	Intrusive Original rock :Granite
			1674 (-10\+10) mill. years;..Method:Pb/Pb
			Metamorphic facies :Greenschist
	Host rock	Amphibolite	Intrusive Original rock :Gabbro
			Metamorphic facies :Greenschist
	Host rock	Granitic mylonite	Intrusive Original rock :Granite
			Metamorphic facies :Greenschist
	Host rock	Banded mylo-gneiss	Extrusive Original rock :Tuff
			Metamorphic facies :Greenschist
	Host rock	Granitic gneiss	Intrusive Original rock :Granite
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Fault plane	Strike/Dip :29 / 90	Post-mineralisation ;...Effect :Modifies
	Host rock	Fault plane	Strike/Dip :63 / 90	Post-mineralisation ;...Effect :Modifies
	Host rock	Fault plane	Strike/Dip :86 / 90	Post-mineralisation ;...Effect :Modifies
	Host rock	Foliation	Strike/Dip :149 / 80	Pre-mineralisation ;...Effect :None
	Host rock	Joints/Fractures	Strike/Dip :241 / 85	Syn-mineralisation ;...Effect :Controls
	Host rock	Joints/Fractures	Strike/Dip :248 / 63	Syn-mineralisation ;...Effect :Controls
	Host rock	Joints/Fractures	Strike/Dip :263 / 70	Syn-mineralisation ;...Effect :Controls
	Host rock	Joints/Fractures	Strike/Dip :263 / 80	Syn-mineralisation ;...Effect :Controls
	Host rock	Joints/Fractures	Strike/Dip :266 / 70	Syn-mineralisation ;...Effect :Controls
	Host rock	Fault plane	Strike/Dip :266 / 90	Post-mineralisation ;...Effect :Modifies
	Host rock	Fault plane	Strike/Dip :280 / 65	Post-mineralisation ;...Effect :Modifies
	Host rock	Joints/Fractures	Strike/Dip :294 / 65	Syn-mineralisation ;...Effect :Controls
	Host rock	Fault plane	Strike/Dip :294 / 75	Post-mineralisation ;...Effect :Modifies
	Host rock	Fault plane	Strike/Dip :315 / 80	Post-mineralisation ;...Effect :Modifies
	Host rock	Foliation	Strike/Dip :324 / 75	Pre-mineralisation ;...Effect :None
	Host rock	Shear plane	Strike/Dip :350 / 80	Pre-mineralisation ;...Effect :None

Information(s) in free text format

Free text

The Brustad mine is situated 1 km northwest of Lake Nordre Holsjøen at the end of the road running along the western shore of the lake. The road stops at the spoil heaps outside the open cut leading into the main adit, which has collapsed. The dirt road up to the open pits is marked by a sign at the parking place. The mine has been periodically in operation from 1720ties to 1907, first as a copper mine and since 1758 as a gold mine. During the last ten years of its operation gold was extracted metallurgically from sulphide concentrates produced by gravimetric separation of the ore minerals on shaking tables. Remnants of the old ore dressing plant is still visible in the hillside 100-200 m metres north of the mine and thick deposits of waste sand on the plains down to Lake Putten in the west. The mine comprises four open pits, one inclined shaft and one vertical shaft, which connect the underground workings down to 100 m with surface. A total of about 50 000 tonnes of crude ore containing 2-15 g/t Au was produced from the Brustad mine. The ore mineralisation is located on a nearly 1500 m long ESE-WNW-trending system of milky quartz veins which only in its easternmost 400 m, where the mine is located, carry sulphides and associated native gold. The veins in the mine area are 0,1-4 metres thick with normal thicknesses in the range 1-2 metres. They dip 50º-70º north and intersect granitic augen gneisses and mylonites in the Brustad mine and an amphibolitic gabbro sill (hyperite) in the Lovisa mine to the west, where only low-grade ores occur (1-2 g/t Au). The quartz veins are controlled by three prominent fracture directions including NE-SW, ENE-WSW to E-W and ESE-WNW to SE-NW. The latter two prevail in the Brustad mine, giving the veins an undulating course along strike. The vein in the Brustad mine has been off-set down dip and along strike by vein-parallel post-ore faults leading to the formation of to parallel veins in the pits. The repetion of the vein is probably caused by normal faulting with an oblique dextral component. The quartz veins are invariably enveloped by silicified and quartz-sericite-altered wall rocks which also may contain abundant thin veins and veinlets of quartz. The sericite alteration enveloping barren quartz veins carry only accessory pyrite. In the amphibolitic gabbro chlorite and magnetite become important constituents of the sericite alteration. Pyrite replacing magnetite and occurring as dense dissemination and along quartz veinlets in the alteration envelopes, only occurs in those segments of the quartz veins, which contain fractures and cavities filled with abundant pyrite. Microscopic examinations reveal several paragenetic stages including 1) early massive barren quartz veins (locally with comb structure) enveloped by sericite±pyrite±magnetite alteration, 2) main pyrite stage associated with fracturing of the early quartz veins, 3) chalcopyrite stage with replacement of cataclastic pyrite and associated deposition of Ag-rich galena, native gold/electrum and late hematite, 4) barren quartz veins and 5) post-ore faulting with associated deposition of amorphous carbon (coalblende) and minor pyrite in the quartz veins and adjacent gneisses which receive a dark grey to black decolouration. The native gold mainly occurring intergrown with chalcopyrite, are generally very fine-grained (< 20 mm). Though ore samples contain up to 137 g/t Au, no visible gold grains have been found, which is a characteristic feature for the gold deposits in the Eidsvoll area.

Bibliography:

From NGU's Reference Archive:

Brustad gruber, Akershus

	Brustad gruber. Snitt av loddsjakt, forslag til gallerier 1:200 Plankart over gruben 1:300.

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 2

Carstens, C. W. , 1934

	Skriv til direktør Munster i Metalkemi, oslo om Brustadgruben i Eidsvoll.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 2941;4 pages

Abstract:

Rapporten inneholder et skriv til direktør Munster i Metalkemi om at utmålsbrev på Brustadgruven og et mutingsbrev på Sandergruben er til salgs. Brustadgruben er godt beskrevet.. prøver på berghaller omkring gruven er analysert og viser 21 og 37 gAu/ tonn. Rapporten inneholder også analyseresultater for 4 gullanalyser Utført ved Metallurgiskt Laborotorium i Stockholm for Shell & Gurholt A/B, Oslo.

Henriksen, G.

	Brustad grube. Oversiktskart

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 2279

Henriksen, G.

	Brustad grube. Oversiktskart

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 2278

Smith, H. H. , 1909

	Svovelkisforekomstene Eines, Falstad, Barstad, Stangeholt, Brustad, Vaeraas og Laugsand.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 2995;19 pages

Abstract:

Rapporten er skrevet etter flere besøk i feltet i årene 1904 - 1909. Forekomstens gunstige beliggenhet nær god havn er beskrevet. Geologien består av glimmerskifer, klorittskifer og gabbro. Malmen finnes i flere soner som er fra 0,5 - 4 m mektige og består av svovelkis med svært små mengder kobberkis. 14 utmål er nærmere beskrevet og de mengder kobberkis er tegnet inn på et kartskisse. Videre undersøkelser og drift anbefales. Rapporten inneholder også en teknisk oversikt fra boring av 4 diamantborhull og en borhullslogg fra ett hull.

Stadheim, J. , 1934

	Eidsvold Guldverk. Sp. Brustad -og Sannergruberne.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 631;18 pages

	Abstract:
	Rapporten inneholder utdrag av bergmesterberetningene, for årene 1881 - 1889 og 1896 - 1907, angående driften ved Eidsvoll Gullverk, Brustadgruven, Sannergruve, Græsli Gruve og Boshaugdalen skjerp. Rapporten inneholder også Keilhaugs beretning i Magazin for Naturvidenskaberne om det forrige gullverk i Eidsvoll, Docent Carstens' meddelelse og diverse notater.

Thesen, Gudbrand , 1935

	Ad. Brustadverket.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 654;5 pages

	Abstract:
	Rapporten handler om vaskeriets kapasitet og tidligere drift, produksjonens og avgangens størrelse, analyseresultater, gullpriser, utvinningsutgifter, driftsoverskudd, malmtonnasje og gehalt. Bergmesterrapporter for tidsrommet 1880 - 1934 er vedlagt (2 sider).

Brustad gruber, Akershus

	Brustad gruber. Vertical projection to coordinaten X 1:300

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 1

Name of Locality: Stollpåhugg

(Object Id: 15824 5,01,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629395 m.

North:

6701930 m.

Longitude:

11.3509480

Latitude:

60.4328700

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Fe-sulphides

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit and underground mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :248 / 75
	Host rock	Joints/Fractures	Strike/Dip :248 / 70

Name of Locality: Østre brudd

(Object Id: 15825 5,02,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629350 m.

North:

6701937 m.

Longitude:

11.3501360

Latitude:

60.4329480

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Fe-sulphides

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :266 / 70

Name of Locality: Skråsjaketen

(Object Id: 15826 5,03,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629330 m.

North:

6701941 m.

Longitude:

11.3497760

Latitude:

60.4329900

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Fe-sulphides Cu

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :330 / 70	Syn-mineralisation ;...Effect :Controls

Name of Locality: Midtre brudd

(Object Id: 15827 5,04,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629315 m.

North:

6701948 m.

Longitude:

11.3495080

Latitude:

60.4330570

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Cu Pb Bi Ag

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :285 / 70

Name of Locality: Hovedsjakten

(Object Id: 15828 5,05,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629240 m.

North:

6701939 m.

Longitude:

11.3481410

Latitude:

60.4330010

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Fe-sulphides Cu

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :256 / 70

Name of Locality: Prinseese Luise/Lovise

(Object Id: 15829 5,06,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629019 m.

North:

6701961 m.

Longitude:

11.3441440

Latitude:

60.4332690

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Au Fe-sulphides Cu

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit and underground mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :294 / 65

Name of Locality: Sofie gruve

(Object Id: 15830 5,07,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629102 m.

North:

6701863 m.

Longitude:

11.3455870

Latitude:

60.4323630

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Cu Pb Au

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit and underground mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :241 / 85

Name of Locality: Sofie sjerp

(Object Id: 15831 5,08,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629151 m.

North:

6701899 m.

Longitude:

11.3464990

Latitude:

60.4326700

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Fe-sulphides

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :263 / 90

Name of Locality: Ryggen sjerp

(Object Id: 15832 5,09,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629201 m.

North:

6701895 m.

Longitude:

11.3474040

Latitude:

60.4326180

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	fe-sulphides

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :239 / 90

Name of Locality: Søndre sjerp

(Object Id: 15833 5,10,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629242 m.

North:

6701846 m.

Longitude:

11.3481170

Latitude:

60.4321660

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Fe-sulphides Au

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :263 / 80

Name of Locality: Tveter skjerp sør

(Object Id: 15834 5,11,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629615 m.

North:

6701556 m.

Longitude:

11.3544780

Latitude:

60.4280320

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Cu Au

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :143 / 90

Name of Locality: Tveter skjerp nord

(Object Id: 15835 5,12,00)

Location

County:

Municipality:

Mangler ()

Map 1:50000:

Eidsvoll (1915-1)

Map 1:250000:

Hamar

Coordinate system:

UTM-Zone 33 - EUREF89/WGS84

East:

629658 m.

North:

6701457 m.

Longitude:

11.3554150

Latitude:

60.4285430

Show on map

Resource

	Resource Type:	Precious metals (Au,Ag,PGE)	Resource Subtype:	Gold
			Element(s):	Cu Au Fe-sulphides

Resources and production

	Activity:	Mining	Reserves:
	Operating method:	Open pit mining	Historical production:

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Hydrothermal vein	Strike/Dip :250 / 90

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The fact sheet was created on 18.04.2024

Copyright © 2024 Geological Survey of Norway