Geochemical analysis was undertaken on a 3.75 metre cored interval of apparently monotonous laminated, black, organic-rich shales from the Upper Devonian to Lower Carboniferous Exshaw Formation of southern Alberta. Utilizing a combination of hand-specimen description, Rock-Eval pyrolysis, optical petrography and inorganic geochemistry, the shale is divided into: 1) a lower organic-poor and silt-rich interval; and 2) an upper organic- and clay-rich interval. The Exshaw shales were deposited in a marine shelf setting below the influence of storm wave-base on the block faulted unstable craton of western North America. Bottom waters were anoxic. The lower region of the core includes a series of sharp-based, silt-rich layers that exhibit low TOC, HI and organic-proxying elements, whereas OI, C-org/N-org, ratio and silt-sized quartz detritus exhibit high values. These layers are interpreted as sediment gravity flows sourced from paleobathymetric high features, and transported silt-sized quartz and allochthonous degraded marine organics to the site of deposition. Concurrently, the redoxcline was depressed in the water column, facilitating the degradation of settling autochthonous organic matter. In contrast to the lower section, geochemistry of upper parts of the core reflects an increase in primary productivity and consequent shoaling of the redoxcline in the water column. This is evidenced by an increase in TOC, HI and organic-matter proxying elements, and a decrease in the OI and C-org/N-org ratio. As a consequence of shoaling of the redoxcline in the water column, a greater proportion of relatively labile organic matter was preserved. This study demonstrates that factors in addition to bottom water anoxia govern organic matter accumulation and preservation of organic-rich sedimentary facies. Geochemical evidence suggests that these factors include sediment size, primary productivity, organic source and contemporaneous diagenesis of organic matter in the water column.