"During the colonial period, circle monographs, reports by colonial administrators, geologists, amateurs, etc. also provide information that can often prove decisive in the collection of preliminary data. Within these, metallurgist sites are often indicated on maps and photographs. Authors also describe metallurgical industries. This approach most often allows for the establishment of an initial general mapping of archaeological sites and thus an assessment of the wealth of metallurgical sites in the study area in order to prepare field surveys."