CAG in Brief: The Colloquium of African Geology (CAG) is a major biennial meeting organized under the auspices of the Geological Society of Africa (GSAf). Since the first Colloquium in 1965, the Colloquia have been hosted by several European and African countries. The African countries that had a chance to organize this event were Swaziland, Zimbabwe, Morocco, Mozambique, Tunisia, South Africa and Ethiopia. Based on the decision of the Geological Society of Africa (GSAf) General Assembly held on 14th January 2013 at the Millennium Hall, Addis Ababa, Ethiopia (during the 24th Colloquium), the organization of the next Colloquium of African Geology (CAG25) as well as the 15th Conference of the Geological Society of Africa was assigned to Brazil. However, because of administrative problems in organizing the 25th CAG along with the Brazilian Geological Society of Brazil Conference in September 2014, the GSAf Council members decided to move the CAG25 to another country. Based on the discussion between Prof. Aberra Mogessie (President of the Geological Society of Africa) and Prof. Sospeter Muhongo, Minister of the Ministry of Energy and Minerals of the United Republic of Tanzania, in Graz Austria, in August 2013 it was decided to organize the CAG25 back to back with the 3rd YES Congress in Tanzania. This decision was approved by the GSAf Council members. The CAG25 is an independent meeting which will be organized by the Tanzania Geological Society (TGS) under the auspices of the GSAf.