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	THE ORE DATABASE
	Deposit Area 937 - 010
	(Last updated 13.mar.2024)

Importance

Public:

Not Assessed (reg. 20.03.2017)

Economical:

Significant , (Confirmed 19.mar.2007 by Morten Often)

Historical:

Yes , (Confirmed 16.feb.2005 by Havard Gautneb)

Products

	Element/product	Crude ore grade or quality
	CO	0,015
	CU	.48 %
	NI	.72 %
	P	4 %

Operations

	From - To	Activity	Comments
		Geophysics
	1872 - 1946	Regular production
	1933 - 1944	Core drilling
	1990 - 1991	Geology

Mineralization

	Era:	Proterozoic	Period:	Mesoproterozoic
	Dating:		Method:
	Genesis:	Orthomagmatic formation	Form:	Lens
	Main texture:	Structureless	Min. distribution:	Semi-massive (20-50 % ore minerals)

Main grain size:

Medium grained (1-3 mm)

Main alteration:

Chloritisation

	Strike/Dip:	10 / 45	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Mesoproterozoic

	Province:	South Norwegian Basement Province
	Geotec.unit:	Setesdal-Hallingdal Complex
	Tectonic complex:
	Igneous complex:	Evje Amphibolite Complex

Group:

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Biotite	Major mineral (>10%)
	Gangue mineral	Amphibole	Major mineral (>10%)
	Gangue mineral	Chlorite	Subordinate mineral (1-10%)
	Gangue mineral	Apatite	Subordinate mineral (1-10%)
	Gangue mineral	Pyroxene	Accessory mineral (<1%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)
	Ore mineral	Pentlandite	Subordinate mineral (1-10%)
	Ore mineral	Chalcopyrite	Subordinate mineral (1-10%)
	Ore mineral	Pyrite	Subordinate mineral (1-10%)
	Ore mineral	Millerite	Accessory mineral (<1%)
	Ore mineral	Violarite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Unknown	Mykleås amphibolite	Intrusive Original rock :Diorite
			1000 mill. years;..Method:Rb/Sr
			Metamorphic facies :Amphibolite
	Host rock	Flåt diorite	Intrusive Original rock :Quartz diorite
			950 mill. years
			Metamorphic facies :Amphibolite

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Unknown	Shear plane	Strike/Dip :10 / 80	Syn-mineralisation ;...Effect :None
	Unknown	Fault plane	Strike/Dip :10 / 35	Post-mineralisation ;...Effect :Controls

Information(s) in free text format

Free text

The Flåt nickel-copper deposit is associated with a plagioclase-rich diorite, located on the western margin of a larger, early Sveconorwegian complex, the Iveland-Gautestad metagabbroic complex. The Flåt ore was was mined from 1844 as a copper deposit, from 1872 as a copper-nickel deposit. The mine was worked intensively during WW II and was closed in 1946. Total production is estimated to have been 2.7 Mt, containing 20,200t Ni, 14,500t Cu and 2,400t Co. The deposit forms a pencil-shaped body underlain by an irregular body of gneiss. Typical ore contains 12-13% sulphide, 75% silicates, 8% magnetite and 4% apatite. The major sulphides are pyrite, pyrrhotite, pentlandite and chalcopyrite.

Bibliography:

From NGU's Reference Archive:

Bjørlykke, Harald , 1947

	Flåt nickel mine.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.168b;1-39 + fo pages

Barth, Tom F. W. , 1947

	The Nickeliferous Iveland-Evje amphibolite and its relation.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.168a;1-71 + fo pages

Abstract:

The pre-Cambrian nickelferous meta-norite at Iveland-Evje represents an amphibolite body entirely surrounded by gneissous granite and augen genisses. More than 90% of the amphibolite body is made up with schistose or gneissic rocks in most of which alternating dark and light layers have developed through the combined effect of recrystallization and internal differential movements. So thorough has been the re-working of the material that the determination of the nature of the original rock is utterly impossible. The conclusion that at least part of this rock was norite is based entirely on circumstancial evidences, such as the association with nickel ore, and the petrographical analogy of certain facies of the Evje rock with nickelferous norite elsewhere. The individual dark and light bands, although sharply separated, are composed of exactly the same kinds of mineral: Plagioclase has the same chemical composition, and hornblende and biotite exhibit the same optical constants in both bands; only the relative proportions of the minerals differ radically. In some places banding is not well developed, but light and dark constituents have separated in concretionary patches.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	FLÅT 06-1	Hand specimen	Sampler :M. Often Comment :Diorite, with cp and po. From "Koparhola". No. of registrated element analyses = 1
	FLÅT 06-2	Hand specimen	Sampler :M. Often Comment :Diorite, with cp and po. From "Koparhola". No. of registrated element analyses = 1
	FLÅT 06-3	Hand specimen	Sampler :M. Often Comment :Diorite, with sulphides. No. of registrated element analyses = 1
	FLÅT 06-4	Hand specimen	Sampler :M. Often Comment :Diorite, with sulphides. No. of registrated element analyses = 1

NB! All analyse values are shown at the end of the printout.:

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Analyse Results

from

Deposit Area 937 - 010 Flåt/Evje

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#
FLÅT 06-1	Hand specimen	49706	293	54	214	5398	20.0	121.0
FLÅT 06-2	Hand specimen	9962	84	33	253	17936	6.3	170.0
FLÅT 06-3	Hand specimen	3080	128	28	140	4265	2.0	19.0
FLÅT 06-4	Hand specimen	3721	101	66	102	5209	2.0	30.0

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Sample No.	Pt#	Pd#	As*	Cd*	Mo*	Bi*	S%	V*	Cr*
FLÅT 06-1	14.0	9.0	5	2.2	1.00	3	7.70	101	241
FLÅT 06-2	66.0	15.0			2.00		13.70	100	314
FLÅT 06-3	16.0	3.0					3.50		66
FLÅT 06-4	8.0	-2.0		-.5			3.60	91	92

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Sample No.	Mn*	Fe%	Th*	U*	Sr*	La*
FLÅT 06-1	208	16.07	4.00	1.00	62.0
FLÅT 06-2	226	24.94
FLÅT 06-3		7.19			128.0
FLÅT 06-4		10.87			94.0	54.00

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The fact sheet was created on 01.11.2024

Questions or comments regarding the fact sheet can be emailed to: ressursdatabaser@ngu.no

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