A new provenance tool for the exploration of Unconventional Plays - The provenance and mineralogy of silt

Provenance analysis has traditionally focused on sandstones, which are much easier to analyse than conglomerates - which must be analysed in the field with limited tools - and mudrocks - which cannot be dealt with easily with classical optical methods. However, it is important to recognise that the silt fraction transported in suspension actually represents the majority of the sediment in large river systems and the predominant grain-size in major deltas and submarine fans, as well as in most of ancient sedimentary basins and reservoirs. Quantitative provenance analysis of silt represents a step forward in provenance studies as it provides the access to an unexplored world where detrital minerals can be easily identified and their history reconstructed. The technique can be applied to both siltstone and shale making it attractive for the hydrocarbon industry, particularly in the area of research of Unconventional Plays. This contribution is therefore intended to prove the validity and efficacy of the method and its possible application to both QPA studies and to hydrocarbon exploration. The latter is located in the onshore Mandawa basin in southern Tanzania. where hydrocarbon exploration is particularly important for the presence of huge deepwater gas fields.