The Cambrian sedimentary successions from Sonora, Mexico provides information about the sedimentary and geological evolution that occurred on the western margin of Laurentia. The sedimentary rocks from the Fortunian to Jiangshanian stages denote eustatic changes. Initially (Fortunian to Stage 3), shallow water marine clastic-carbonate deposits are found in northwest Sonora. These deposits comprise tidal flats and lagoons with storm deposits and reefs dominated by archaeocyaths. The Stage 4 to Wuliuan sedimentary succession represents the most documented Cambrian transition in Mexico, which includes deposits from the shoreline - beach conditions, lagoon and restricted inner platform with low diversity of polymerid trilobites, to an outer platform - deep shelf margin with abundant agnostids. On the other hand, the sedimentary environments during the Drumian to Guzhangian changed from an outer shelf marine environment to a shallow water marine platform. And finally, rocks from the Paibian to Jiangshanian denote an outer shelf transition to a middle to outer shelf margin.