Abstract Two general types of Archean gold deposits are known in the Quebec segment of the Abitibi belt (Robert 1990) (Table 1). Firstly, there are gold-quartz vein deposits where gold is commonly associated with the development of quartz-carbonate vein systems. These deposits are typified by the deposits of such as the Pierre Beauchemin, Silidor and Donalda and Sigma deposits (Robert and Brown 1986). Secondly there are pyritic gold deposits where quartz-carbonate veins are less important and where sulphide generally form a major part of the ore. Deposits of the Bousquet area are good examples of this second type. This classification, although satisfactory to distinguish Archean gold deposits in general sense, needs be further refined in consideration of the broad characteristics of many individual deposits (Tourigny et al. 1989; Tourigny, this volume). The Francoeur #3 deposit presents distinct geological characteristics which make it difficult to classify in either the Au-quartz vein or pyritic gold deposit type. During this mine visit, we will show that there exists a distinct type of gold-only deposit which present significant common geological differences resulting from possible different ore forming processes. The study of such deposits is thus important considering that proposed models might not fully explain their differences nor adequately predict their occurrences.