The objectives of the Geological Society of Africa (GSAf) are to develop research and education related to the earth sciences in Africa. The biennial Colloquium of African Geology is one of the most important international scientific meetings that are jointly organized by the Society and the country that has won the bid to organize it. During the CAG 22 held in Tunisia, Nov.4-6, 2008 the GSAf had its 13th Conference, during which a decision was made to organize the CAG 23 in South Africa after the successful presentation by the chair of the South African bid Committee, Dr. Hassina MOURI of the University of Johannesburg.

During this colloquium we expect to have special symposiums dealing with different aspects of the earth sciences in Africa and elsewhere. As such I expect the participation of as many South African Geologists as possible, plus a number of geologists from other African countries as well as colleagues from abroad who are engaged in earth science research and education in Africa. I also believe that the participants will have a chance to know South Africa, its beauty and its remarkable geology, which will motivate them and plan to attend the IGC 35 in Cape Town in 2016.

As President of the GSAf, and in the name of the council members, I would like to thank all South African Geological Institutions, especially the University of Johannesburg, as well as national and international organizations and institutions, for the support they are providing for the successful organization of this colloquium.. I look forward to seeing you at the Colloquium.