Alkaline Rocks and Carbonatites of the World

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



Occurrence number: 
Longitude: 41.5, Latitude: 13.28

Three large volcanoes, which from north to south are Nabro (2100 m), Mallahle (Mallali) and Asavyo (Mohr and Wood, 1976), are aligned along a north-northeasterly direction on the Danakil block. Each has a large summit caldera, that on Nabro being double with diameters of 10 and 5 km. Nabro and Mallahle comprise a complex strato-volcano which emitted very large volumes of rhyolitic products, mostly pyroclastics but some flows. Obsidian domes, pumice deposits and basaltic spatter cones and flows are located within and around the calderas, which they post-date. Many basaltic flows were emitted from fissures. Petrographic details of the rocks have not been found but the rhyolitic rocks are probably peralkaline.


BARBERI, F., CHEDEVILLE, E., FAURE, H., GIGLIA, G., MARINELLI, G., SANTACROCE, R., TAZIEFF, H. and VARET, J. 1973b. Geology of Northern Afar (Ethiopia) (with a geological map, scale 1:500,000). Revue de Geographie Physique et de Geologie Dynamique, Paris, 15: 443-89.

Fig. 3_70 Bidu (after Barberi et al., 1973b).
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith