Alkaline Rocks and Carbonatites of the World

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

Klipdrift

stripes

Occurrence number: 
151-00-021
Country: 
South Africa
Region: 
Pienaars River Alkaline Complex (Franspoort Line)
Location: 
Longitude: 28.27, Latitude: -25.43
Carbonatite: 
No

This plug has a north-south diameter of nearly 1 km and cuts granite of the Bushveld Complex. It comprises a hornblende syenite which envelops a central quartz syenite. The quartz syenite is a uniformally textured rock of strongly zoned, euhedral alkali feldspar, aegirine/diopside, a sodic amphibole and interstitial quartz (Harmer, 1985). Xenoliths in the syenites and veins cutting the surrounding granites are described as 'soda trachyte' while syenite aplites cut the outer part of the plug.

Age: 
A Rb-Sr isochron giving an age of 1306±11 Ma was obtained by Harmer (1985) by combining data from Klipdrift with data from Franspoort (No. 151-00-027), Buffelsdrift and Haakdoornfontein, the last two being part of Roodeplaat (No. 151-00-025), but the data on Klipdrift alone define an age of 1422±514 Ma.
References: 

HARMER, R.E. 1985. Rb-Sr isotopic study of units of the Pienaars River alkaline complex, north of Pretoria, South Africa. Transactions of the Geological Society of South Africa, 88: 215-23.VERWOERD, W.J. 1967. The carbonatites of South Africa and South West Africa. Geological Survey of South Africa, Handbook, 6: 1-452

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