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	THE ORE DATABASE
	Deposit Area 437 - 062
	(Last updated 18.sep.2008)

Importance

Public:

Little Importance (reg. 18.02.2015)

Economical:

Minor interest , (Confirmed 18.mar.2002 by Jan Sverre Sandstad)

Operations

	From - To	Activity	Comments
	1999 - 1999	Sampling	Company/Institution :NGU

Mineralization

	Era:	Proterozoic	Period:	Neoproterozoic
	Dating:		Method:
	Genesis:	Volcex	Form:	Lens
	Main texture:	Banded	Min. distribution:	Semi-massive (20-50 % ore minerals)

Main grain size:

Fine grained (< 1 mm)

Main alteration:

No country rock alteration

	Strike/Dip:	340 / 35	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Proterozoic

Period:

Neoproterozoic

	Province:	Caledonides
	Geotec.unit:	Trondheim Nappe Complex
	Tectonic complex:	Gula Nappe
	Igneous complex:

Group:

Gula

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Garnet	Major mineral (>10%)
	Gangue mineral	Amphibole	Major mineral (>10%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)

Lithology:

	Relationship	Rock	Origin
	Wall rock	Amphibolite	Extrusive Original rock :Basalt
			Metamorphic facies :Amphibolite

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Wall rock	Schistosity	Strike/Dip :326 / 30	Post-mineralisation ;...Effect :Modifies
	Wall rock	Foliation	Strike/Dip :335 / 35	Post-mineralisation ;...Effect :Modifies

Information(s) in free text format

Free text

Forekomsten ligger ca. 100 m nordøst rett nord for Bubakken klebersteinsbrudd. En bomvei fører fra Moen og opp til kleberbruddet som ligger 960 moh. I sulfidskjerpet er det sprengt ut en opptil 3 m høy skjæring med vegger på 2x2 m på sørsida av en mindre nordvest-sørøst orientert rygg. Forekomsten er registrert av Nilsen (1978), men det er ikke kjent når det ble skjerpet i området. Trolig skjedde dette i tilknytning til driften av forekomstene på Børsjøhø. Berggrunnen langs ryggen domineres av middelskornet amfibolitt som dels er granatførende og dels fører smale biotittrike soner. Sulfidmineraliseringen er linseformet og 1-2 m mektig. Den består av semi-massive, dels massive magnetkis bånd i kvartsrikere soner amfibolitten. Sterk til moderat disseminasjon av magnetkis finnes i granatførende amfibolitt som omgir disse båndene. Mineraliseringen er uten økonomisk interesse. Lokalisering sjkket og justert 13.09.2008.

Photo(s) from the Deposit area:

Photo no. 1 showing Gråhø skjerp"

Bibliography:

From NGU's Reference Archive:

Nilsen, Odd , 1978

	Caledonian sulphide deposits and minor iron-formations from the southern Trondheim region, Norway.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.340;35-85 + k pages

Abstract:

Within the southern and central parts of the Trondheim region of the Norwegian Caledonides a great number of small, stratabound cupriferous pyrite deposits are confined to mafic metavolcanics of the Gula, Støren and Fundsjø Groups of the Lower Palaeozoic succession. The deposits occuring within, or in close contact with the metavolcanics are characterized by their association with minor manganiferous oxide/silicate iron-formations - better known as "vasskis" ore type - within the metamorphic low-grade areas. The iron-fprmations of the metamorphic higher grade terrains on the other hand, which are extensively developed within the Gula Group, are mostly of a pyrrhotitic sulphide/silicate type and sulphurization processes are thought to have played an important role during the metamorphism. The pyrite deposits occurring adjacent to the metavolcanics bear no relationship to the iron-formations. They are embedded in pelitic, often carbonaceous assemblages (Gula Group) or within tuffitic members of the volcanogene Støren Group, and they are thought to represent re-sedimented (reworked) deposits. The pyrite deposits display varying degree of metamorphic reconstitution and a tectonic control has apparently determined their disc- or ruler-shaped morphology.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	HE0170.01	Bedrock	Sampler :J.S. Sandstad/...Stored :Løkken Comment :Semi-massiv, finkornet magnetkis i kvartsrik grunnmasse No. of registrated element analyses = 1
	HE0170.02	Bedrock	Sampler :J.S. Sandstad/...Stored :Løkken Comment :Moderat-sterk disseminasjon av magnetkis i granat-amfibolitt 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 437 - 062 Gråhø

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#
HE0170.01	Bedrock	704	58	20	53	94	1.1	20.0
HE0170.02	Bedrock	386	44	12	16	38	.7	47.0

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Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
HE0170.01	17.0	6.0	2	.4	48	14.00	7	2	11.46
HE0170.02	1.0	2.0	4	.1	17	3.00	2	2	2.97

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Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
HE0170.01	46	20	1505	23.47	2.00	4.00	4	79.0	19.00
HE0170.02	45	58	1462	9.14	2.00	4.00	4	34.0	17.00

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Sample No.	B*
HE0170.01	3
HE0170.02	2

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The fact sheet was created on 18.05.2024

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

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