Fact Sheet for <b>Occurence 1813

					Norsk versjon
	THE ORE DATABASE
	Occurence 1813 - 005 Flatvatnet
	(Object Id: 2276) (Last updated: 10.02.2006)

Location

County:

Nordland

Municipality:

Brønnøy (1813)

Map 1:50000:

Velfjord (1825-4)

Map 1:250000:

Mosjøen

Coordinate system:

EU89-UTM Zone 33

East:

386152 m.

North:

7251868 m.

Longitude:

12.5513890

Latitude:

65.3696910

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Resource

	Resource Type:	Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn)	Resource Subtype:	Copper
			Element(s):	Kis Cu

Importance

Raw material meaning:

Little Importance (reg. 18.02.2015)

Resources and production

	Activity:	Exploration	Reserves:
	Operating method:		Historical production:

Operations

From - To Activity Comments

1982 - 1983 Geochemistry Company/Institution :BP Norge A/S Minerals

1988 - 1988 Geology Company/Institution :NGU-malmreg

Mineralization

Era: Paleozoic Period: Devonian

Genesis: Hydrothermal vein Form: Plate

Main texture: Fracture filling Min. distribution: Massive (>50 % ore minerals)

Main grain size: Coarse grained (> 3 mm) Main alteration: Others

Strike/Dip: Direction:

Plunge:

Stratigraphic classification of host rock

Era: Paleozoic Period: Ordovician

Province: Caledonides

Geotec.unit: Helgeland Nappe Complex

Tectonic complex:

Igneous complex:

Group: Formation:

Mineralogy

Relationship Mineral Amount

Gangue mineral Quartz Major mineral (>10%)

Gangue mineral Amphibole Subordinate mineral (1-10%)

Ore mineral Pyrrhotite Major mineral (>10%)

Ore mineral Chalcopyrite Subordinate mineral (1-10%)

Lithology:

Relationship Rock Origin

Host rock Amfibolitt Intrusive
Original rock :Monzodiorite

Wall rock Marmor Sedimentary
Original rock :Limestone

Metamorphic facies :Contact

Structures

Location: Type: Orientation(360 gr.): Relation to min.:

Host rock Joints/Fractures Strike/Dip :111 / 90 Syn-mineralisation ;...Effect :Controls

Wall rock Mineral banding Strike/Dip :198 / 75 Pre-mineralisation ;...Effect :None

Information(s) in free text format

Free text

Forekomsten, som ligger i en veiskjæring ved Flatvatnet, ble påvist av BP Norge A/S Minerals i forbindelse med oppfølging av gull-anomalier i Velfjordområdet. Den opptrer inne i et monzodioritt-gabbro-massiv og nær dets kontakt mot omgivende metasedimentære bergarter. Mineraliseringen omfatter et "en echelon"-system av kvarts-magnetkis-ganger som har strøk/fall 111/90. Gangene fører massive årer og segregasjoner av magnetkis som i enkelte ganger er det dominerende mineral. Gangene opptrer ca. 2 m fra kontakten til en inneslutning av marmor og er omgitt av amfibolittisert gabbro/monzodioritt. Kvartsgangene når mektigheter på 30 cm og har en utstrekning på noen meter. 20 m lengre øst langs en liten sidevei opptrer en 20 cm bred magnetkisgang (str./fall 120/90) i flytebåndet monzodioritt. Den gjennomsettes av tynne kalkspatårer i tilknytning til en knusningssone med str./fall: 34/85.

Bibliography:

From NGU's Reference Archive:

Myrland, Rolf , 1972

Velfjord. Beskrivelse til det berggrunnsgeologiske gradteigskart I 18 - 1:100 000.

;Norges geologiske undersøkelse;KARTBESKRIVELSE; TIDSSKRIFTARTIKKEL;NGU; Skrifter; No.274; 1;1-30 + ka pages

Abstract:

The various lithologies are described. These comprise granitic basements rocks of supposed Pre-Cambrian age and Cambro-Silurian supracrustals and intrusives. The intrusives are mostly found within the Bindal and Velfjord massifs. These massifs are younger than the supracrustals, but their mutual age relationship is uncertain. Tectonically the rocks are sitated in "the high metamorphic nappe-complex" of central and western Helgeland. The supracrustal rocks have undergone at least three phases of Caledonian folding, the F2 phase producing the main regional structures. The rocks have mineral assemblages which place them in the almandine-amphibolite metamorphic facies.

Barnes, Calvin G.; Prestvik, Tore; Nordgulen, Øystein; Barnes, Melanie A. , 1992

Geology of three dioritic plutons in Velfjord, Nordland.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU Bulletin; No.423;41-54 pages

Abstract:

Dioritic plutons in the Velfjord area of Nordland intrude calc-silicates and migmatitic pelites of the Helgeland Nappe Complex (HNC). The three largest plutons were emplaced in a zone of NNW-SSE regional strike rather than the more typical NE-SW strike. The plutons postdate Caledonian F2 structures; however, anatectic granites increase in abundance toward the plutons, which suggests emplacement and subsequent partial melting of the pelitic host rocks soon after peak metamorphism. The dioritic and granitic bodies were deformed with interstitial melt present; deformation continued during cooling to greenschist facies conditions. Structural position, style and timing of deformation, and assymetric zoning of the plutons are consistent with intrusion into a dilatant part of a regional sinistral shear zone.

From - To	Activity	Comments
1982 - 1983	Geochemistry	Company/Institution :BP Norge A/S Minerals
1988 - 1988	Geology	Company/Institution :NGU-malmreg

Era:	Paleozoic	Period:	Devonian
Genesis:	Hydrothermal vein	Form:	Plate
Main texture:	Fracture filling	Min. distribution:	Massive (>50 % ore minerals)

	Province:	Caledonides
	Geotec.unit:	Helgeland Nappe Complex
	Tectonic complex:
	Igneous complex:

Relationship	Mineral	Amount
Gangue mineral	Quartz	Major mineral (>10%)
Gangue mineral	Amphibole	Subordinate mineral (1-10%)
Ore mineral	Pyrrhotite	Major mineral (>10%)
Ore mineral	Chalcopyrite	Subordinate mineral (1-10%)

Relationship	Rock	Origin
Host rock	Amfibolitt	Intrusive Original rock :Monzodiorite
Wall rock	Marmor	Sedimentary Original rock :Limestone
		Metamorphic facies :Contact

Location:	Type:	Orientation(360 gr.):	Relation to min.:
Host rock	Joints/Fractures	Strike/Dip :111 / 90	Syn-mineralisation ;...Effect :Controls
Wall rock	Mineral banding	Strike/Dip :198 / 75	Pre-mineralisation ;...Effect :None