Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Wigu Hill

stripes

Occurrence number: 
163-00-030
Country: 
Tanzania
Location: 
Longitude: 37.57, Latitude: -7.43
Carbonatite: 
Yes

Although this occurrence has been investigated as a potential source of rare earths, few detailed geological descriptions are available. Wigu Hill consists of Precambrian gneisses which are cut and fenitized by a system of intersecting dolomitic dykes together with explosion vents of carbonatite and fenite breccias. Although most of the dykes are dolomitic some sovite also occurs; most dykes contain fenite xenoliths. The main minerals of the carbonatites are dolomite and calcite with barite, celestite, bastnasite, monazite, cerian goyazite, quartz and minor pyrite and sphalerite. The cerian goyazite is described by McKie (1962).

Economic: 
Zones up to a little over a metre wide and 150 m long have been delimited in which rare earth oxides may reach 16-20%. The main assemblage of REE minerals is bastnasite, monazite and cerian goyazite (Deans, 1966).
References: 

DEANS, T. 1966. Economic mineralogy of African carbonatites. In O.F. Tuttle and J.Gittins (eds), Carbonatites, 385-413. John Wiley, New York. GITTINS, J. 1966. Summaries and bibliographies of carbonatite complexes. In: O.F. Tuttle and J. Gittins (eds), Carbonatites. 417-541. John Wiley, New York. Geological Survey of Tanganyika, Memoir, 2: 1-172.HARRIS, J.F. 1961. Summary of the geology of Tanganyika. Part IV: Economic geology. Memoir, Geological Survey of Tanganyika, 1: 1-143.MCKIE, D. 1962. Goyazite and florencite from two African carbonatites. Mineralogical Magazine, 33: 281-97.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith