Hoggar phonolithic dike

The Nineteenth International Geological Congress held in Algiers in September 1952 brought together more than 1,100 participants. Answers are given to some questions: 1° how was it decided that this congress would be held in Algiers? 2° how was geology organized in North Africa? 3° what role did the organizing committees play? 4° what was the numerical importance of the national delegations? 5° how the meetings of the Congress Council and those of the fifteen thematic sections took place. In addition, the geological cruise of the liner "Chamollion" along the Algerian-Tunisian coasts and the numerous excursions throughout North Africa and even West Africa are mentioned. The congress finally made it possible to publish numerous publications which testified to the progress made to that date in the geological knowledge of North Africa.