Alkaline Rocks and Carbonatites of the World

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

Inkweyri

stripes

Occurrence number: 
114-00-029
Country: 
Mozambique
Location: 
Longitude: 34.75, Latitude: -18.73
Carbonatite: 
No

The Inkweyri hills consist of olivine nephelinite which cuts sediments of Cainozoic age on the eastern side of the Urema graben. This is a dense rock with occasional olivine phenocrysts up to 2 mm in length in a groundmass of olivine, augite, nepheline, magnetite and perovskite, with numerous poikilitic plates of orange biotite.

Age: 
Post-upper Cainozoic.
References: 

TEALE, E.O. and SMITH, W.C. 1923. Nepheline-bearing lavas and intrusive rocks from south of the Zambezi River, with a note on an outcrop of Karroo lavas in the Buzi Valley, Portuguese East Africa. Geological Magazine, 60: 226-37.

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