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	THE ???? DATABASE
	Occurence 0 - 000 FEIL
	(Object Id: ) (Last updated: 08.05.2006)

Products

	Element/product	Crude ore grade or quality	Reg. date
	Cu	8 %	31.01.2000

Operations

	From - To	Activity	Comments
	1885 - 1889	Regular production	Company/Institution :Tronsliens Grubebolag
	1891 - 1892	Regular production	Company/Institution :Kristiania Minecompagni
	1906 - 1911	Test mining	Company/Institution :a/s St. Knuts gruber
	1958 - 1958	Inspection	Company/Institution :Folldal Verk AS
	1969 - 1969	Geophysics	Company/Institution :NGU
	1969 - 1969	Core drilling	Company/Institution :Folldal Verk AS ?
	1970 - 1970	Geophysics	Company/Institution :NGU ?
	1973 - 1973	Geophysics	Company/Institution :NGU ?
	1998 - 1998	Sampling	Company/Institution :NGU mineralressurser

Mineralization

	Genesis:	Unknown	Form:	Irregular
	Main texture:	Structureless	Min. distribution:	Irregular (scattered)

Main grain size:

Very unevenly grained

Main alteration:

Chloritisation

	Strike/Dip:		Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Paleozoic

Period:

Ordovician

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

Group:

Hummelfjell Group

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Chlorite	Major mineral (>10%)
	Gangue mineral	Muscovite	Subordinate mineral (1-10%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)
	Ore mineral	Chalcopyrite	Major mineral (>10%)
	Ore mineral	Pyrite	Subordinate mineral (1-10%)
	Ore mineral	Sphalerite	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Chlorite-muscovite schist	Sedimentary Original rock :Greywacke
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Host rock	Axial plane	Strike/Dip :166 / 28
	Host rock	Foliation	Strike/Dip :225 / 53	Post-mineralisation ;...Effect :Controls
	Host rock	Fold axis	Dir./Plunge :282 / 20	Post-mineralisation ;...Effect :Controls

Information(s) in free text format

Free text

Deposits in the Tron Area The Tron area comprises a larger field of ore deposits, which are located along at least two major ore-bearing, copper-rich horizons. The area is situated at the southern foot of Tron at an elevation between 700 and 800 m.a.s.l. The main deposits are St. Knut, Gamle Tronsli, St. Thomas and the two Tjæremyr deposits. History: The Gamle Tronsli and Tjæremyr deposits were worked by Folldal Verk in the period 1770-80 under the name "Tronen gruber". The St. Knut and St. Thomas were worked in more recent years, i.e. in the period between 1885 and 1911. Except for St. Knut, there are no information available about when they were in operation, production or ore grades. Gamle Tronsli was worked by Folldal Verk in the period from 1770-80. A shaft is reported to have been worked to a depth of 40 m and also a 70 m long adit towards the south at a depth of 20 m. St. Knut, located about 100 m south of Gamle Tronsli was found in the beginning of the 1880s and in the first years of operation it delivered ore with high grades of copper. In the years 1885-86 it was produced about 300 t ore at a grade of 8.5 % Cu and in addition a fair amount of ore for upgrading. However, the grades and widths of the ore veins decreased at depth and the production ceased already in 1889 after a production of only 512 t of ore. The company Kristiania Minekompagni leased the deposit in 1891, but the production failed after only one year and a production of 180 t ore with a grade of 8 % Cu. The St. Knut mine produced all together 772 t of ore with a grade of 8 % Cu. A new company, AS St. Knuts gruber, bought the rights to the whole Tron area. This company did considerable exploration work in the area, both at the surface and in the mines St. Knut and St. Thomas. The ore zones in the St. Knut mine was followed along strike for about 800 m and is located in the small Braanaa deposits, as well as in the St. Olaf mine. The westernmost intersection of this zone is the Tronsvangen deposit, where a shaft was worked down along the ore zone. St. Knut mine was worked by a shaft to a depth of about 55 m and from the bottom a 150 m long adit was worked northwards, intersecting the Gamle Tronsli ore zone, as well as a third ore zone 40 m to the north of this. An other adit from the west of Tronsvangen deposit, with a length of 1000 m was started which was supposed to underlie all the deposits, including St. Knut. Only 90 m were worked before the company was broke. This was in 1911, and after this no work has been done in the area. Geology The ore in all the deposits are of a very similar type and consists mainly of pyrrhotite and chalcopyrite in rich impregnation and semimassive/massive lenses irregularly distributed in chlorite-quartz rock. Pyrite and some sphalerite is found locally. Weaker impregnations of pyrrhotite and chalcopyrite occur in schists consisting of chlorite and sericite with high contents of quartz. The ore zones are generally very thin, between 10 and 50 cm. Typically, there are several thinner zones, which have been strongly folded leading to enriched stocks of ore parallel the regional fold axes, which trend westwards with shallow plunge. This is especially demonstrated in an open pit at the St. Knut mine. The ore zones are surrounded by an alteration halo, with enrichment of chlorite, sericite and quartz, relative to the host rock, which are semipelitic to psammitic chlorite-muscovite schist. From the map by Aalen (1908) and as stated by Riiber (1923), it appears that the St. Knut and Braanaa mines are located along the same ore zone, whereas it seems that the Gamle Tronsli mine, the Tjæremyr mines, St. Thomas and Tronsvangen mine are located along another parallel zone, about 100 m to the north. St. Olaf and a small working south of St. Thomas belongs to a third zone, apparently enriched in sphalerite and galena, compared to the other two zones.

Bibliography:

From NGU's Reference Archive:

Aalstad, I. , 1967

	Magnetisk og elektromagnetisk flymåling Dovre-Alvdal

;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.687;7 pages

Holmsen, P.; Thesen, G.; Rasmussen, W. , 1907

	A/S St. Knuts gruver.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 2203;24 pages

	Abstract:
	Rapporten beskriver gruvenes historie og selve forekomstene. Rapportene er: Aftryk af trondhjemske bergdistrikts befaringsprotokol av Holmsen, 1887 og 1889, Gudbrand Thesens rapport fra 1892, W. Rasmussens rapport fra 1906 og 1907 og Per Mortensons rapport fra 1907. Forfatter forts.: P. Mortenson.

Aalen, O. E. , 1908

	St.Knut gruve. Oversiktskart St.Knut, Gml.Tronsli, St.Thomas og Tjæremyr 1:1 000

;Norges geologiske undersøkelse;KART;Bergarkivet; No.K 2578

Thorkildsen, Birger , 1913

	St. Knuts Grubefelt, Lilleelvdal.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 6440;3 pages

Abstract:

Befaringsrapport for St. Knuts Grubefelt. Malmen er blottet ved Saataa, St. Olav, St. Thomas, øvre og nedre Tjæremyr, Braanaa I og II, Gamle Tronsli grube og Tronsli kletten. Det er tilsynelatende 3 gangsoner med kobberkis, magnetkis og svovelkis i skiferen. Malmlinsene er ikke særlig store og malmen er svært uregelmessig. Det er i tiden 1885 - 1893 solgt 722 tonn malm med gjennomsnittlig 8% Cu. St. Knut og Tjæremyrgrubene synes å være de beste forekomstene.

Riiber, Carl C. , 1923

	Rapporter over kis -og kobbergruber og skjerp i Foldal, Dovre og Alvdal herreder.

;Norges geologiske undersøkelse;FAGRAPPORT;Bergarkivet; No.BA 3194;25 pages

Abstract:

Rapporten omfatter følgende gruver og skjerp: I. Foldals verks gruber: a. Hovedgruben. b. Nordre Gjeitryggen grube. c. Søndre jetryggen grube, d. Grev Moltke grube. e. Grimsdalen grube. f. Storthaab grube. g. Boksberg grube. II. Statens kisanvisninger: a. Skjerp øst for Foldals verks hovedgrube. b. Stretlien skjerp. c. Grimsdalen skjerp. III. Grimsbo kisskjerp. IV. Rødalens kobbergrube. V. Tronfjeldets kobbergruber. VI. Verkjendalens kisfelt. Rapporten beskriver forekomstenes beliggenhet, geologiske forhold, malmen, resultater av undersøkelser (boringer, analyser osv.), salgspriser, historiske forhold, juridiske forhold og kraftsituasjonen. Forekomstnr.: 1. 10963, 2. 10973 og 3. 10991. Forekomstens navn og koordinater: 1. Folldal 32 5521 68908, 2. Verkensdalen 32 5281 68816, 3. Gamle Tron 32 5862 68910.

Eidsvig, Per; Sindre, Atle , 1969

	Geofysiske målinger Stormyra, Hjerkinn. St. Knuts Grube, Tron.

;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.847;26 pages

References not to be found in NGU's Reference Archive.:

H.P. Geis 1958: Verkets skjerp ved Alvdal. Befaringsrapport for Folldal Verk, 7 sider.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	HE0096.01	Bedrock	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: mm banded quartz-rich chlorite-sericite schist with bands of rich pyrrhotite-chalcopyrite impregnation. sample from open pit, west of main shaft. No. of registrated element analyses = 1
	HE0096.02	Bedrock	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: Chalcopyrite aggregates associated with quartz-lenses in chlorite schist. Scattered pyrrhotite. Sample from pit to the west of main shaft No. of registrated element analyses = 1
	HE0096.03	Bedrock	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: Folded quartz-sericite schist with lesser chlorite. Weak impregnation of chalcopyrite and possibly pyrite. Sample from hangingwall above main shaft (north face). No. of registrated element analyses = 1
	HE0096.04	Dump	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: Rich chalcopyrite impregnation in chlorite with quartzlenses, grading into chloritic sericite schist with weak, fine-grained chalcopyrite-pyrrhotite impregnation. Hostrock looks like coarse, somewhat altered psammite/arkose. No. of registrated element analyses = 1
	HE0096.05	Dump	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: Fine-grained weak impregnation of chalcopyrite and pyrrhotite in chloritic, coarse grained muscovite quartz schist, possibly altered psammite/arkose. No. of registrated element analyses = 1
	HE0096.06	Bedrock	Sampler: T. Bjerkgård/...Stored: Løkken/...Size(kg): 3 Comment: Strongly deformed, mylonitic muscovite-chlorite schist. Not mineralized. Sample from pit to the west of main shaft. No. of registrated element analyses = 1

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

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The fact sheet was created on 29.04.2024

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