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THE INDUSTRIAL MINERAL DATABASE
Occurence 4624 - 302 Horgaberg
(Object Id: 7960)
(Last updated: 03.11.2006)

Location
County: Vestland Municipality: Bjørnafjorden (4624)
Map 1:50000: Fusa (1215-3) Map 1:250000: Bergen
Coordinate system: EU89-UTM Zone 32
East: 316399 m. North: 6680067 m.
Longitude: 5.6857970 Latitude: 60.2159080
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Resource
Resource Type: Silica Resource Subtype: Quartzite

Importance
Raw material meaning: Little Importance (reg. 18.02.2015)

Resources and production
Activity: Stone quarrying Reserves:
Operating method: Open pit mining Historical production:


Products
Element/product Crude ore grade or quality Reg. date
Abrasive 10.05.2006
Metallurgical use 10.05.2006
Slag conditioner 10.05.2006

Operations
From - To Activity Comments
1950 - 1968 Regular production Company/Institution :Norwegian Talc A/S (Jacob Kjøde)

Mineralization
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:

Information(s) in free text format
Free text
Norwegian Talc AS mined fine-grained quartzite at Horgaberg, 1.5 km south of the settlement Bakka in two neighbouring quarries for gravel production. The quarries can be reached by a 2 km long and steep forest road starting at Kvåle at the state road 552. The Proterozoic quartzites belong to the Caledonian Slettafjell Nappe of the Upper Allochthon. The quarries are on the foot of nearly vertical, up to 100 m high wall. The cm-scale lamination of the quartzite is caused by greyish to greenish coloration. Some layers with a thickness of up to 10 cm consist of pure milky quartz of economic quality with Al2O3 and CaO+Na2O+K2O <0.5 wt.% (sample 2508505). These layers are bordered by thin biotite and chlorite bands. Beside quartz the rock commonly contains muscovite (up to 5 vol.%) and accessory biotite and chlorite. The foliation plane dips flat SW. The Horgaberg quartzite contains fine-crystalline quartz (average of 0.3 mm) of high chemical quality (8 to 16 ppm Al, 1 to 3 ppm Ti, 0 to 1 ppm Li). However, the deposit is not of economic interest for quartz production due to the heterogeneous and variable mineralogy and chemistry and the small grain size of quartz. Fra første bind av boken "Heilt andre tider" av Elle Marie Brekke Vangsne, en ny bygdesogebok i tre deler fra Fusa: "Vanvik kvartsbrudd leverte si første skipslast med kvartshaldig stein 7. mars 1950. Kvartsen skulle til Thamshavn i Orkdal og brukast som tilslag under smelting av svovelkis frå Orkla gruver. Dei som stod bak kvartsbrotet var Norwegian talc A/S, eit selskap under Jacob Kjøde A/S. 6-8 mann var sysselsette med å sprengja. På det meste opp mot 20 mannn i arbeid. Fram til 1960 var brotet i full drift - avtale med Orkla gruver. Kontrakten vart ikkje fornya. Det vart levert kvarts til Ålvik og Sauda der han vart nytta som råstoff i produksjonen av ferrosilisum. Frå 1960 vart drifta redusert til produksjon av berre singel og sand, og arbeidsstokken krympa til 5 mann. Drifta var ikkje lønsam og 28. februar 1968 var det slutt. "

Photo(s) from the Deposit area:
Photo no. 1 showing Horgaberg quartzite"
Photo no. 2 showing thin section image"

Fieldsamples
Sample No. Sample type Miscellanrous
2508505a Bedrock
Sampler: Muller/...Stored: NGU
Comment: quartzitic mylonite gneiss from the disused quarry
No. of registrated element analyses = 1
No. of registrated mineral analyses = 2
No. of registrated oxide analyses = 1
2508505b Bedrock
Sampler: Muller/...Stored: NGU
Comment: pure quartzite layer (10 cm thick) from the disused quarry
No. of registrated element analyses = 1
No. of registrated mineral analyses = 1
No. of registrated oxide analyses = 1
NB! All analyse values are shown at the end of the printout.:


Analyse Results
from
Deposit Area 4624 - 302 Horgaberg

Element analyses

( *=parts pr. million, #=parts pr.billion, Negative values means below detection limit value.)
Sample No. Sample Type Cu* Zn* Pb* Co* Ni* As* Ba*
2508505a Bedrock -10 8 -10 7 -5 -5 75
2508505b Bedrock -10 8 -10 7 -5 -5 45
------------------
Sample No. Mo* Sn* Sb* Ga* V* Cr* Th* U* W*
2508505a -5.00 -10 -10 -10.00 -10 13 10.00 -10.00 25
2508505b -5.00 -10 -10 -10.00 -10 -10 8.00 -10.00 27
------------------
Sample No. Rb* Sr* Y* Zr* Nb* Ta* Cs* La* Ce*
2508505a 17.0 -5.0 6.0 56 -5.00 -10.00 -10.00 -10.00 11.00
2508505b 7.0 -5.0 -5.0 47 -5.00 -10.00 -10.00 -10.00 -10.00
------------------
Sample No. Pr* Nd* Yb* Sc* Hf*
2508505a 10.00 -10.00 -15.00 -10.00 -10.00
2508505b -10.00 -10.00 -15.00 -10.00 -10.00

Mineral analyses

( All values are in ppm. Negative values means below detection limit value.)
Sample No. Sample Type Mineral Li Be B
2508505a Bedrock Quartz -.500 -.100 1.300
2508505a Bedrock Quartz .700 -.100 1.100
2508505b Bedrock Quartz -.500 -.100 .700
------------------
Sample No. Na Al P K Ti Fe Ge
2508505a -22.000 12.300 -6.000 -1.400 3.100 4.500 .700
2508505a -22.000 15.400 -6.000 -1.400 1.700 22.300 .800
2508505b -22.000 8.700 -6.000 -1.400 1.900 -.300 .800

Oxide analyses

( All values are in % )
Sample No. Sample Type SiO2 Al2O3 TiO2 Fe2O3 MnO MgO CaO
2508505a Bedrock 97.47 1.19 0.04 0.18 -0.01 0.02 0.02
2508505b Bedrock 99.15 0.36 0.02 0.07 -0.01 -0.01 0.00
------------------
Sample No. Na2O K2O P2O5 Loss Sum
2508505a 0.00 0.52 -0.01 0.20 100.00
2508505b 0.00 0.17 -0.01 0.07 100.00


The fact sheet was created on 18.01.2022

Questions or comments regarding the fact sheet can be emailed to:
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