Norsk versjon
	THE ORE DATABASE
	Deposit Area 1739 - 008
	(Last updated 25.feb.2005)

Importance

Public:

Little Importance (reg. 18.02.2015)

Economical:

Minor interest , (Confirmed 18.feb.2005 by Havard Gautneb)

Products

	Element/product	Crude ore grade or quality
	CU	1.2 %
	NI	3.6 %
	PGE	5.6 ppm

Operations

	From - To	Activity	Comments
	1916 - 1917	Test mining	Company/Institution :A/S Elektrokemisk Industri
	1958 - 1958	Geophysics
	1959 - 1959	Core drilling
	1970 - 1970	Geophysics
	1977 - 1977	Geophysics
	1995 - 1995	Geology	Company/Institution :NGU

Mineralization

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

Main grain size:

Very unevenly grained

Main alteration:

	Strike/Dip:	240 / 50	Direction:
			Plunge:

Stratigraphic classification of host rock

Era:

Paleozoic

Period:

Ordovician

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

Group:

Gjersvik

Formation:

Mineralogy

	Relationship	Mineral	Amount
	Gangue mineral	Albite	Major mineral (>10%)
	Gangue mineral	Hornblende	Major mineral (>10%)
	Ore mineral	Pyrite	Major mineral (>10%)
	Ore mineral	Pyrrhotite	Major mineral (>10%)
	Ore mineral	Pentlandite	Major mineral (>10%)
	Ore mineral	Chalcopyrite	Subordinate mineral (1-10%)
	Ore mineral	Magnetite	Subordinate mineral (1-10%)
	Ore mineral	PGE-minerals	Accessory mineral (<1%)

Lithology:

	Relationship	Rock	Origin
	Wall rock	Greenstone	Extrusive Original rock :Basalt
			Metamorphic facies :Greenschist
	Wall rock	Gabbro	Intrusive Original rock :Gabbro
			Metamorphic facies :Greenschist

Structures

	Location:	Type:	Orientation(360 gr.):	Relation to min.:
	Wall rock	Foliation	Strike/Dip :245 / 60	Post-mineralisation ;...Effect :None

Information(s) in free text format

Free text

The deposit is located 4-5km N of Skorovass, not far from the access road. It was identified by Lars and Peder Staldvik in 1912. The rights to the deposit were handed to the A/S Elektrokjemisk Industri that had some prospection done in the summers of 1916-17. A 2m wide cut was made at 18m from the deposit¿s strike, at parts up to 4m deep. Furthermore, a 6m long cross-cut was driven in the north hanging wall. In 1931, several Norwegian sulphide ores were assayed for noble metals by Mimi Johnson Høst for an NGU contract. It was found that Lillefjellklumpen contained exceptionally high platinum group metals (Foslie & Høst 1932). The Lillefjellklumpen is situated in the Gjersvik nappe (Grønlie 1988). The massive sulphide ore occurs on the border between gabbroic rock and greenstone. The contact with the gabbro is sharp and the greenstone of the hanging wall is fine grained with a felsic structure. Both are situated in the upper part of a vein complex that forms the bedrock of the Skorovassklumpen (Sandstad et al 1996). The massive sulphide ore body consists of pyrrhotite, pyrite, pentlandite, chalcopyrite, magnetite, and silicates. The ore is clean and only contains 2vol% silicates according to modal analysis. Two types have been registered: 1) pyrrhotite containing pentlandite and magnetite, which is the predominant type, and 2) pyrrhotite-chalcopyrite ore that is subordinate, mostly occurring in outer parts of the deposit. Chalcopyrite is common as aggregates in the matrix and/or thin vein networks. Average Ni-content is 3.6wt%, Cu is 1.2wt%. Total PGE¿s is 5.6ppm, Pt (1.8ppm) and Pd (3.1ppm) account for 4.9ppm together. The ratio Pt+Pd/Ru+Ir+Os is 9.8, which is typical for gabbro-related deposits. The ore consists of irregular lenses of massive sulphide. The deposit probably represents a magmatic sulphide segregation related to an ensimatic gabbro body, later again remobilized by tectonic events and finally deposited in its current position.

Bibliography:

From NGU's Reference Archive:

Grønlie, Arne , 1988

	Platinum-group minerals in the Lillefjellklumpen nickel-copper deposit, Nord-Trøndelag, Norway

;Norsk geologisk forening;TIDSSKRIFTARTIKKEL;Norsk geologisk tidsskrift; No.68 (1);65-72 pages

Abstract:

The Lillefjellklumpen Ni-Cu deposit occurs in the Gjersvik Nappe in the Upper Allochthon of the central Norwegian Caledonides. The area has been interpreted by earlier workers as part of an ensimatic island arc of Lower to Middle Ordovician age. The mineralization is associated with a small body of metagabbro occurring at the contact between gabbro and greenstone. The massive sulphide body consists of pyrrhotite, pyrite, pentlandite, chalcopyrite, magnetite and silicates. The average Ni content is 3.6% and th Cu content is 1.2%. The total platinum group element (PGE) content is 5.6 ppm, Pt (1.8 ppm) and Pd(3.1 ppm) accounting for 4.9 ppm. The Pt+Pd/Ru+Ir+Os ratio is 9.8, within the range reported for gabbro related deposits. The average chondrite normalized PGE pattern is similar to that of the Kanichee deposit although Lillefjellklumpen has lower absolute PGE values. Merenskyite is the main platinumgroup mineral (PGM), but sperrylite, moncheite and temagamite (?) also occur. The PGM occur as small (>20 µm) inclusions in pyrrhotite and chalcopyrite as well as on grain boundaries. The Lillefjellklumpen deposit probably represent a magmatic sluphide segregation related to a layer 3 (ensimatic) gabbro body later remobilized during a tectonic event and redeposited in its present position.

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).

Sandstad, Jan Sverre; Dalsegg, Einar; Elvebakk, Harald; Grenne, Tor; Heim, Michael; Meyer, Gurli B. , 1996

	Samtolkning av geodata i Grongfeltet - status pr. 15.12.95

;Norges geologiske undersøkelse;FAGRAPPORT;NGU-rapport; No.95.147

Abstract:

Rapporten oppsummerer undersøkelsene som er utført innenfor prosjektet "Samtolkning av geodata i Grongfeltet" i løpet av 1995, inkludert felt- arbeidet og med de foreløpige resultatene fra dette. Oppfølgende undersøkelser har i hovedsak bestått av geofysiske bakkemålinger (TFEM og Slingram), geologisk kartlegging og fastfjellsprøvetaking. Kjerne- boring ble utført i den nordlige delen av Grongfeltet,i Kirma-området, med to borehull (totalt ca. 300 m), og årsakene til de tidligere påviste elek- triske anomaliene ble påvist. Men de foreløpige resultatene fra boringene gir ingen indikasjoner på funn av sulfidmineraliseringer som kan ha økonomisk verdi. Oppfølging av EM-anomalier i den sørlige delen av feltet har i hovedsak ført til funn av ekshalittmineraliseringer med lavt innhold av kobber og sink. Videre oppfølgende undersøkelser foreslåes i to områder, sørvest for Tunnsjø- flyin og vest for øvre Nesåvatn. Berggrunnskartlegging i målestokk 1;20 000 er gjennomført i Tunnsjøflyin-området og en ny modell for vulkanittstratigrafien innenfor Gjersvikgruppen er foreslått. En foreløpig arbeidsmodell for den magmatiske og metallogenetiske utviklingen av Gjersvikdekkers bergarter presentert i rapporten. Denne vil testes ved tolkning av kjemiske analyser og aldersdateringer i løpet av 1996. Gravimetriske data er innsamlet for å utføre gravimetriske modellberegninger innenfor Gjersvikdekket. Prosjektet ble presentert ved Prospekteringsmessen i Toronto, Canada i mars 1995, bl.a. med en brosjyre og presentasjon av data ved bruk av pc. Tilbake- meldingene fra møtet har vært positive. Norway Gold Exploration har i løpet av året mutet flere områder i Grongfeltet, og et canadisk juniorselskap vurderer små-skala gruvedrift i den sørlige delen; Skiftesmyr- og Godejord- forekomstene.

Foslie, Steinar; Høst, Mimi Johnson , 1932

	Platina i sulfidisk nikkelmalm.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.137;1-71 pages

Abstract:

Im Auftrag der Geologischen Landesanstalt wurde eine Reihe von Erzvorkommen in den Ofoten- und Grong-gebieten, die neulich geologisch kartiert sind, auf ihr Edelmatallgehalt analysiert. Die Analysen wurden im Laboratorium des staatlichen Rohstoffkomitees von Frau Høst ausgeführt, und zwar nach der mikrodokimastischen Methode. Das einzige bekannte Nickelvorkommen innerhalb des Gronggebietes zeigte einen bedeutenden Platin gehalt, und seine Erze wurden daher zum Gegenstand einer genaueren Untersuchung gemacht. Dies veranlasste auch eine Zusammenstellung der zugänglichen Aufgaben über den Platininhalt und die Platingewinnung aus anderen norwegischen und ausländischen Nickelerzen. Bekanntlich sind es nur die südafrikanischen, die in dieser Hinsicht einigermassen gut bekannt sind. Von den anderen - und speziell den wichtigen canadischen - sind nur noch spärliche Aufgaben veröffentlicht. Unter den schwefelkiesreichen Gebieten der Kaledonischen Gebirgskette in Norwegen ist das Gronggebiet eines der wichtigsten.

Fieldsamples

	Sample No.	Sample type	Miscellanrous
	GR91.020	Bedrock	No. of registrated element analyses = 1
	GR91.021	Bedrock	No. of registrated element analyses = 1
	GR91.022	Bedrock	No. of registrated element analyses = 1
	GR91.023	Bedrock	No. of registrated element analyses = 1
	GR91.024	Bedrock	No. of registrated element analyses = 1
	GR91.025	Bedrock	No. of registrated element analyses = 1
	GR91.026	Bedrock	No. of registrated element analyses = 1
	GR91.027	Bedrock	No. of registrated element analyses = 1
	GR91.028	Bedrock	No. of registrated element analyses = 1

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

---

Analyse Results

from

Deposit Area 1739 - 008 Lillefjellklumpen

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#
GR91.020	Bedrock	10767	85	31	1277	24155	3.3	84.0
GR91.021	Bedrock	31121	391	23	1920	9830	9.7	693.0
GR91.022	Bedrock	9250	81	33	869	22106	2.9	33.0
GR91.023	Bedrock	11858	79	26	1779	15419	4.0	105.0
GR91.024	Bedrock	5368	27	34	1411	25079	1.7	84.0
GR91.025	Bedrock	23704	192	26	2060	14423	6.6	281.0
GR91.026	Bedrock	13637	88	31	1678	22825	4.1	67.0
GR91.027	Bedrock	11869	115	25	1864	13772	4.5	77.0
GR91.028	Bedrock	264	47	15	144	221	.1	74.0

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

Sample No.	Pt#	Pd#	As*	Cd*	Ba*	Mo*	Sb*	Bi*	S%
GR91.020	1261.0	2426.0	6	.8	1	1.00	3	30	34.66
GR91.021	1243.0	2416.0	16	5.2	1	1.00	19	17	35.20
GR91.022	101.0	1939.0	2	.2	1	1.00	2	56	33.45
GR91.023	614.0	2151.0	9	.2	7	1.00	2	40	37.55
GR91.024	1511.0	2288.0	4	.2	1	1.00	4	41	36.45
GR91.025	544.0	2056.0	8	3.1	1	1.00	11	2	43.60
GR91.026	4076.0	7184.0	9	1.7	1	1.00	10	41	35.25
GR91.027	1961.0	2225.0	7	.2	1	1.00	2	44	34.25
GR91.028	23.0	48.0	51	.2	1	2.00	2	49	27.30

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

Sample No.	V*	Cr*	Mn*	Fe%	Th*	U*	W*	Sr*	La*
GR91.020	20	170	56	44.24	6.00	5.00	1	1.0	2.00
GR91.021	44	301	62	42.89	3.00	5.00	1	1.0	2.00
GR91.022	40	71	41	49.36	4.00	5.00	1	2.0	2.00
GR91.023	20	430	121	45.05	4.00	5.00	1	4.0	2.00
GR91.024	15	214	21	48.59	5.00	5.00	1	1.0	2.00
GR91.025	21	422	76	45.32	4.00	5.00	1	1.0	2.00
GR91.026	12	212	85	45.36	5.00	5.00	1	2.0	2.00
GR91.027	46	252	42	47.04	5.00	5.00	1	1.0	2.00
GR91.028	32	39	295	15.71	1.00	5.00	1	12.0	2.00

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

Sample No.	B*
GR91.020	3
GR91.021	11
GR91.022	2
GR91.023	2
GR91.024	2
GR91.025	7
GR91.026	11
GR91.027	3
GR91.028	2

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The fact sheet was created on 19.05.2024

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

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