Norsk versjon
	THE INDUSTRIAL MINERAL DATABASE
	Deposit Area 1833 - 330
	(Last updated 07.des.2015)

Importance

Public:

National Importance (reg. 20.02.2015)

Economical:

Very significant , (Confirmed 08.mai.2006 by Rolf Lynum)

Products

	Element/product	Crude ore grade or quality
	SOA/TA	%

Operations

	From - To	Activity	Comments
	1990 - 1992	Core drilling	Company/Institution :Norwegian Talc
	1990 - 1993	Geology	Company/Institution :Norwegian Talc, NTH
	1991 - 1991	Geophysics	Company/Institution :NGU

Mineralization

	Era:	Paleozoic	Period:	Silurian
	Dating:		Method:
	Genesis:	Metasomatic	Form:	Lens
	Main texture:	Structureless	Min. distribution:	Massive (>50 % ore minerals)

Main grain size:

Medium grained (1-3 mm)

	Strike/Dip:	45 / 45	Direction:	45
			Plunge:	45

Stratigraphic classification of host rock

Era:

Paleozoic

Period:

Silurian

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

Group:

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Not defined	Talc	Major mineral (>10%)
	Not defined	Magnesite	Major mineral (>10%)
	Not defined	Magnetite	Accessory mineral (<1%)
	Not defined	Chlorite	Accessory mineral (<1%)

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Wall rock	Foliation	Strike/Dip :60 / 45	Syn-mineralisation ;...Effect :Modifies

Information(s) in free text format

Free text

Store Esjeklumpen is an 800 m long and up to 180 m thick exposed ultramafite situated approximately 3 km south-west of the present mine. The ultramafite is dominated by serpentinite, while talc-carbonate ore is exposed locally outside the serpentinite core. The occurrence of talc-carbonate ore was already known in the 1930's, when a small shaft was driven in the south-western part of the ultramafic body. In the years 1990-1991 two diamond core-drilling programs were established by Norwegian Talc Altermark AS (Edvin Rian) to investigate the size of the ore. The first program formed the basis of a civil engineer thesis by Holter (1990). The second program was included in a doctoral thesis by Karlsen (1995), but is otherwise reported in internal reports by E. Rian and T.A. Karlsen. 3720 m were drilled in the years 1990-1991. Although quite a lot of drill-core information is lacking, an estimated tonnage of around 2.5 mill. tonnes, including both proven, probable and possible resources, is a quite realistic estimate.

Bibliography:

From NGU's Reference Archive:

Søvegjarto, U.; Marker, M.; Graversen, O. , 1988

	Mo i Rana. Berggrunnskart; Mo i Rana; 19271; 1:50 000; trykt i farger;

;Norges geologiske undersøkelse;KART

Karlsen, Tor Arne ; Rian, Edvin ; Olesen, Odleiv , 2000

	Overwiew of talc resources in the Altermark talc province, northern Norway, and possible uses of the talc ore

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU Bulletin; No.436;93-102 pages

Abstract:

Active prospecting during the past 10 years has proved that the Altermark area contains much more talc than previously recognised in the Nakkan-Esjeklumpen area, 10 M tonnes or more of talc-carbonate ore are probably present, distributed in ultramafic bodies. The ore, which occurs as one of several layers within compositionally zoned ultramafic lenses dominated by antigorite serpentinites, has the following general mineralogy; talc (45-65%), carbonate (30-50%), chlorite (0-4%) and magnetite (0-3%). Relative to other known similar deposits, the ore is rather coarse-grained, and the minerals tend to be idio- blastic. Several products can be made from the talc-carbonate ore. By applying flotation or other kinds of mineral separation techniques, it is likely that high-quality talc-concentrate could be made in addition to calc-carbonate mixtures. a concentrate of by-product breunnerite would possibly be of ecomonic value.

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The fact sheet was created on 22.11.2024

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