Fact Sheet for <b>Occurence 5610 - 002 Helligdalen</b>

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	THE ORE DATABASE
	Occurence 5610 - 002 Helligdalen
	(Object Id: 694) (Last updated: 07.02.2007)

Location

County:

Finnmark

Municipality:

Kárášjohka (5610)

Map 1:50000:

Basevuov'di (2032-1)

Map 1:250000:

Inari

Coordinate system:

EU89-UTM Zone 35

East:

444769 m.

North:

7645992 m.

Longitude:

25.6239800

Latitude:

68.9193910

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Resource

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

Importance

Raw material meaning:

Little Importance (reg. 18.02.2015)

Resources and production

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

Mineralization

Era: Cenozoic Period: Tertiary

Genesis: Clastic sediment Form: Irregular

Main texture: Pore space filling Min. distribution: Irregular (scattered)

Main grain size: Very unevenly grained Main alteration:

Strike/Dip: Direction:

Plunge:

Stratigraphic classification of host rock

Era: Period:

Province:

Geotec.unit:

Tectonic complex:

Igneous complex:

Group: Formation:

Mineralogy

Relationship Mineral Amount

Ore mineral Gold Accessory mineral (<1%)

Information(s) in free text format

Abstract

The Helligdalen alluvial gold deposit or Thesens gold field is situated immediately east of Lake Basegurajav'ri in the northern part of Basav'zi valley. The valley forms a narrow gorge probably representing the old river channel of Anarjohka (Bjørlykke, 1966). Gold workings including numerous small pits and presently collapsed shafts, occur over a distance of about 1200 m in the northern part of the valley. The old river bed in the valley consists of an up to 1.2 m thick top layer of fine fluvial sand downwards passing into coarse gravel and sand with about 40 % of large boulders. The lower part of the old river bed contained an average of 1.5 gram/m3 of gold. The gold was frequently coated by iron-oxides (ruste) and therefore difficult to amalgate. A shaft worked in the middle of the valley hit deeply weathered bedrocks, including amphibolites at a depth of 5-6 m. It is therefore assumed, that the gravel and sand in the lowest part of the old riverbed represent reworked pre-clacial weathering.

Bibliography:

From NGU's Reference Archive:

Bjørlykke, Harald , 1966

De alluviale gullforekomster i indre Finnmark.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.236;1-66 pages

Abstract:

The first find of alluvial gold in Finnmarken was made by inspector (bergmester) Tellef Dahll in 1866 in sand from a small river named Nitusjokka near Karasjok. During the following 5 years gold deposits were found in all the rivers of the Tana river systm and the Alta and Reisa rivers. Gold has been found in small amount in all kinds of sand- and gravel deposits and also in the unwashed moraine deposits. The gold fields which have been subject to production or prospection work are situated at the upper parts of the rivers. The occurrences of alluvial gold in Finnmark may be classified in The following way: 1. Preglacial accumulations undisturbed by ice erosion during the ice age. 2: Preglacial accumulations disturbed and redeposited in moraines and fluvioglacial deposits. 3. Accumulations in postglacial river beds. The gold in these deposits seems chiefly to have been washed out from the moraines. Mineralogical analyses of the mineral composition of the gold-bearing sand and gravel have been carried out. The minerals of the gold-bearing deposits may be divided in two groups: 1. Minerals belonging to the surrounding solid rock. 2. Minerals which do not seem to belong to the solid rock in the neighbourhood of the deposits.

Era:	Cenozoic	Period:	Tertiary
Genesis:	Clastic sediment	Form:	Irregular
Main texture:	Pore space filling	Min. distribution:	Irregular (scattered)

	Province:
	Geotec.unit:
	Tectonic complex:
	Igneous complex:

	Relationship	Mineral	Amount
	Ore mineral	Gold	Accessory mineral (<1%)