Alkaline Rocks and Carbonatites of the World

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

Cacca (Kakka, Kaka)


Occurrence number: 
Main Ethiopian Rift
Longitude: 39.23, Latitude: 7.32

On the key of an unpublished map of Di Paola (1976) this volcano, covering about 18x12 km, is shown as comprising "..pantelleritic ignimbrites associated with mugearitic-alkali and peralkaline trachytic central volcanoes." It has a radial dyke swarm (Mohr, 1980). Mohr (1966a) links it with Chilalo (No. 42) as a "trachyte-carbonatite volcanic centre", but now considers the carbonate rocks are not carbonatitic (P.A. Mohr, pers. comm. 1995). A mugearite described in Le Bas and Mohr (1968) contains aegirine-augite.

K-Ar dating of a trachyte from the northeastern slope gave 2.70 Ma (Woldegabriel et al., 1990) and of an alkali trachyte lava from the summit 3.4±0.4 Ma (Mohr and Potter, 1976).

DI PAOLA, G.M. 1973. The Ethiopian rift valley (between 7°00' and 8°40' lat. north). Bulletin Volcanologique, 36: 517-60.DI PAOLA, G.M. 1976. Geological map of the Tullu Moje' volcanic area (Arussi: Ethiopian rift valley). Consiglio Nazionale delle Ricerche, Italy. (unpublished).LE BAS, M.J. and MOHR, P.A. 1968. Feldspathoidal rocks from the Cainozoic volcanic province of Ethiopia. Geologischer Rundschau, 58: 273-80.MOHR, P.A. 1966a. Geological report on the Lake Langano and adjacent plateau regions. Bulletin of the Geophysical Observatory, Haile Sellassie I University, Addis Ababa, 9: 59-75.MOHR, P. 1980. Geochemical aspects of the Sagatu Ridge dike swarm, Ethiopian rift margin. Accademia Nazionale dei Lincei. Atti dei Convegni Lincei. 47: 387-406.MOHR, P.A. and POTTER, E.C. 1976. The Sagatu Ridge dyke swarms, Ethiopian rift margin. Journal of Volcanology and Geothermal Research, 1: 55-71.WOLDEGABRIEL, G., ARONSON, J.L. and WALTER, R.C. 1990. Geology, geochronology, and rift basin development in the central sector of the Main Ethiopian Rift. Bulletin of the Geological Society of America, 102: 439-58.

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