Alkaline Rocks and Carbonatites of the World

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

Lamja

stripes

Occurrence number: 
122-00-045
Country: 
Nigeria
Location: 
Longitude: 11.87, Latitude: 9.85
Carbonatite: 
No

Carter et al. (1963) report the occurrence of lavas about 3 km west of Lamja that are within Cretaceous Numanha shales. They are spheroidally weathered and in thin section reveal altered phenocrysts of olivine, abundant calcite and analcime with a groundmass of iddingsite, cloudy plagioclase laths and magnetite. Nepheline is reported as sometimes being present with a few samples containing leucite. Wright (1976) is suspicious about the accuracy of the identification of the last two minerals.

Age: 
Cretaceous.
References: 

CARTER, J.D., BARBER, W. and TAIT, E.A. 1963. The geology of parts of Adamawa, Bauchi and Bornu Provinces in north-eastern Nigeria. Bulletin, Geological Survey of Nigeria, 30: 1-99.WRIGHT, J.B. 1976. Volcanic rocks in Nigeria. In C.A. Kogbe (ed) Geology of Nigeria, 93-142. Elizabethan Publishing, Lagos.

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