Angola

In an extensive memoir illustrated with geological maps and numerous field photographs Lapido-Loureiro (1973) described all the principal carbonatites of Angola, with an earlier, briefer account (Lapido-Loureiro, 1968). Some chemical and mineralogical data on many of these are to be found in Issa et al. (1991) and discussions of their sub-volcanic structures in Lapido-Loureiro (1969). A relatively full list of occurrences of alkaline rocks as well as carbonatites together with brief descriptions of many of them will be found in Lapido-Loureiro (1967). Apart from the monograph of Lapido-Loureiro (1973) on the carbonatites, detailed accounts of the numerous Angolan occurrences are scarce. For the majority of occurrences there are few or no data on the field relationships with only petrographic accounts of one or a few specimens available. In spite of this there are many papers considering the spatial distribution of the Angolan alkaline rocks, noting that they are concentrated in a few provinces and that they define clear lines (e.g. Lapido-Loureiro, 1968). A geochemical study of 29 specimens from six carbonatite complexes is that of Alberti et al. (2000)