Alkaline Rocks and Carbonatites of the World

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

Nailuwa

stripes

Occurrence number: 
103-00-019
Country: 
Malawi
Region: 
Chilwa Province
Location: 
Longitude: 35.07, Latitude: -15.08
Carbonatite: 
Yes

This locality is described by Garson (1965b) as being “6 miles north of Utale Mission” but on his Map 1 it is indicated as being close to the village of Nailuwa, which I have taken as the name. A hand specimen from a small agglomerate outcrop in Precambrian gneiss comprised very fine-grained fragments of a rock consisting of turbid feldspar, quartz, iron oxides and acicular apatite. Garson could discern a vague trachytic texture and speculated that the xenolths are silicified and altered trachyte. The matrix consists mainly of calcite with siderite, goethite and some quartz. These carbonates are arranged in zones around the xenoliths. This rock is interpreted as a carbonatite agglomerate.

References: 

GARSON, M.S. 1965d. The geology of the area west of Lake Malombe, Fort Johnston District. Records, Geological Survey of Malawi, 3: 35-48.

Map: 
Fig. 3_150 The location of Kangankunde and the lesser carbonatite localities of the Shire valley (Nos 17-24). (after Garson, 1965b, Map 1).
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith