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	THE ORE DATABASE
	Occurence 5043 - 017 Gudfjelløya
	(Object Id: 252) (Last updated: 16.05.2006)

Operations

	From - To	Activity	Comments
	1991 - 1991	Sampling	Company/Institution :NGU

Mineralization

	Era:	Paleozoic	Period:	Ordovician
	Genesis:	Volcex	Form:	Layer
	Main texture:	Banded	Min. distribution:	Massive (>50 % ore minerals)

Main grain size:

Medium grained (1-3 mm)

Main alteration:

	Strike/Dip:	60 / 30	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Paleozoic

Period:

	Province:	Caledonides
	Geotec.unit:	Køli Nappe Complex
	Tectonic complex:	Gjersvik Nappe
	Igneous complex:	Skorovass Complex

Group:

Gjersvik

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Quartz	Major mineral (>10%)
	Gangue mineral	Chlorite	Major mineral (>10%)
	Gangue mineral	Plagioclase	Major mineral (>10%)
	Ore mineral	Pyrite	Major mineral (>10%)
	Ore mineral	Magnetite	Subordinate mineral (1-10%)

Lithology:

	Relationship	Rock	Origin
	Host rock	Greenstone	Extrusive Original rock :Basalt
			Metamorphic facies :Greenschist

Information(s) in free text format

Free text

Forekomsten ligger ca. ved kote 650 på NV-siden av toppen på Gudfjelløya. Terrenget her er åpent og lite overdekket. For å komme hit må man ha båt fra Møkkelviktangen og gå den merkede stien fra Øyheim. Man bøyer av mot nord ved kote 600 (hvor stien dreier mot sør). Meget bratt! En mer enn 300 m lang horisont, hvor den totale rustsonen kan bli nesten 10 m mektig. Det meste av mektigheten utgjøres av disseminert svovelkis i grønnstein. Vasskishorisonten, som er smal og av ujevn mektighet, viser skjelett-tekstur på overflaten,- et forvitringsfenomen. Liggen utgjøres av grønnskifer. En blotning nede ved Tunnsjøen på NØ-siden av øya er horisontens fortsettelse mot nord. Rustsonen sees forøvrig fra riksveien på "fastlandet". Mot Brennbakken forsvinner sonen, muligens under overdekning. Analyser av disseminert svovelkis viser 0.2 % Zn og 0.4 % Mn.

Bibliography:

From NGU's Reference Archive:

Oftedahl, Christoffer , 1958

	Oversikt over Grongfeltets skjerp og malmforekomster.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.202;1-75 + fo pages

Abstract:

Ore occurences of the Grong area: In the period 1910-1918 a great number of ore occurences were discovered in the Grong area. The late state geologist Steinar Foslie mapped the area in the years 1922-1931. Foslie also mapped all claims and occurences and made special field investigations in a few cases. This book presents a survey of all occurences chiefly based on the field observations of Foslie. In addition the present author has done some field work in connection with the three large deposits, Joma, Skorovass, and Gjersvik. The map, Plate 1, shows the areal geology and the location of the occurrences, numbered from 1 to 131. the ore of the occurrences is chiefly pyrite. The larger occurrences also contain some chalcopyrite and sphalerite etc. and the smaller occurrences contain ither pure pyrite with some magnetite. The Joma deposit (No. 1), contains about 15.5 mill. tons of ore. The ore zone forms an arc and is situated within a thick series of greenstones (Fig. 1). The Skorovass mine (No. 2), contains about 7,5 mill. tons of ore. The deposit is situated in a greenstone complex (Fig. 7), and is immediately surrounded by asid tuffs of quartz keratophyric composition (Table 1).

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	LS91115	Bedrock	Sampler: Størseth, L.R. Comment: Pyrite dissemination in greenstone. No. of registrated element analyses = 1
	LS91116	Bedrock	Sampler: Størseth, L.R. Comment: Fine grained pyrite ore with magnetite bands. No. of registrated element analyses = 1
	LS91117	Bedrock	Sampler: Størseth, L.R. Comment: Massive, fine grained pyrite ore, quartz rich. No. of registrated element analyses = 1

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

Name of Sample point: Gudfjelløya

(Object Id: 8964 17,00,01)

Location

County:

Trøndelag

Municipality:

Raarvihke (5043)

Map 1:50000:

Tunnsjøen (1924-3)

Map 1:250000:

Grong

Coordinate system:

EU89-UTM Zone 33

East:

422132 m.

North:

7179179 m.

Longitude:

13.3651840

Latitude:

64.7282970

Show on map

Resource

	Resource Type:	Base metals (Cu,Zn,Pb,Fe sulphides, As,Sb,Bi,Sn)	Resource Subtype:	Sulphides
			Element(s):	Kis

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	LS91118	Bedrock	Sampler: Størseth, L.R. Comment: Thin, fine grained, massive pyrite ore in felsic rock. No. of registrated element analyses = 1

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

---

Analyse Results

from

Deposit Area 5043 - 017 Gudfjelløya

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#
LS91115	Bedrock	135	1478	9	40	17	.8	19.0
LS91116	Bedrock	561	55	65	38	19	5.1	41.0
LS91117	Bedrock	45	202	88	5	26	7.7	56.0
LS91118	Bedrock	78	16	12	33	20	1.5	29.0

------------------

Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
LS91115	1.0	1.0	31	2.9	5	1.00	2	2	5.41
LS91116	1.0	1.0	164	.2	3	12.00	2	12	24.02
LS91117	1.0	1.0	54	.2	10	28.00	2	2	18.62
LS91118	1.0	1.0	96	.2	14	105.00	2	2	10.30

------------------

Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
LS91115	204	13	4552	11.41	1.00	5.00	1	5.0	2.00
LS91116	9	13	108	19.09	1.00	5.00	1	2.0	2.00
LS91117	10	41	163	17.77	1.00	5.00	1	1.0	2.00
LS91118	78	9	117	11.38	1.00	5.00	1	30.0	2.00

------------------

Sample No.	B*
LS91115	2
LS91116	8
LS91117	6
LS91118	3

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The fact sheet was created on 04.05.2024

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