Fact Sheet for Deposit Area 1740

					Norsk versjon
	THE INDUSTRIAL MINERAL DATABASE
	Deposit Area 1740 - 302
	(Last updated 23.nov.2006)

Name of Deposit Area : Størje

(Object Id : 1740,302,00,00)

Location

County :

Nord-Trøndelag (17)

Municipality :

Namsskogan (1740)

Map 1:50000:

Røyrvik (1924-4)

Map 1:250000:

Grong

Marking point:

Longitude:

13.3592570

Latitude:

64.9644610

EU89-UTM Zone 33

(Coordinates NOT confirmed)

X-coord:

422532 m.

Y-coord:

7205498 m.

Commodity

Main Type:

Olivine

Sub Type:

Ultramafic (unspec.)

Importance

Public: Not Assessed (reg. 18.02.2015)

Economical: Not classified/evaluated

Mineralization

Era: Period:

Dating: Method:

Genesis: Form:

Main texture: Min. distribution:

Main grain size:

Strike/Dip: Direction:

Plunge:

Stratigraphic classification of host rock

Era: Period:

Province:

Geotec.unit:

Tectonic complex:

Igneous complex:

Group: Formation:

Bibliography:

From NGU's Reference Archive:

Lutro, O.; Kollung, S. , 1983

Røyrvik. Berggrunnskart; Røyrvik; 19244; 1:50 000; sort/hvitt;

;Norges geologiske undersøkelse;KART

Lutro, Ole , 1979

The geology of the Gjersvik area, Nord-Trøndelag, central Norway.

;Norges geologiske undersøkelse;TIDSSKRIFTARTIKKEL;NGU; No.354;53-100 + pages

Abstract:

The Gjersvik area consist of low-grade metamorphic rocks overlain in the west by the higher grade Helgeland Complex. The low-grade sequence is divided into three groups: the Gjersvik, the Limingen and the Røyrvik Groups. The Gjersvik and the Limingen Groups constitute a redefined Gjersvik Nappe, thrusted above the Røyrvik Group. The stratigraphy within the Gjersvik Nappe is inverted. The greenstones and felsic rocks in the Gjersvik Group are of tholeiitic affinity and are thought to represent part of a Lower or Middle Ordovician island arc complex which was affected by sea floor weathering after deposition. Parorogenic movements, possibly in Middle Ordovician time, led to erosion of the Gjersvik Group and the formation of a polymict conglomerate marking the basal unit of the Limingen Group. This group consists mainly of calcareous metasediments of shallow water origin and is probably of Middle to Upper Ordovician age. The Røyrvik Group consists of phyllites, often bituminous, associated with quartzites and some greenschists. The group has been an uncertain age and stratigraphical position. The Helgeland Nappe Complex in the map area is composed of metasedimentary gneisses and schists intruded by a tonalite.

	Era:		Period:
	Dating:		Method:
	Genesis:		Form:
	Main texture:		Min. distribution:

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