Shallow marine sedimentary sequences are often associated with high energy processes, acting upon the environment of deposition. One of the main sedimentary events is storm-associated conditions. Near the city of Ensenada, B.C., several sedimentary sequences have been identified by the author as storm-deposited beds or Tempestites. The studied sequences range from the Upper Cretaceous Rosario Formation at Mesa de Los Indios, Punta Banda, and Peñasco La Lobera to the Paleocene Sepultura Formation at Mesa de La Sepultura. The interpretation of these deposits was based mainly on primary sedimentary structures, such as hummocky cross stratification and swaley cross stratification. Both of these structures have been accepted as clear indicators of storm-related conditions. The presence of ichnofossils also made possible the identification of the ichnofacies embodied in these sequences. In addition, the body fossils are always just fragments further supporting interpretation of the high-energy conditions during deposition. Only when the body fossil or sedimentary structure is either too robust or has the hydrodynamic form of a blue-green algal ball or oncolite, is it completely preserved. One evident observation is the higher frequency of the shallower swaley cross stratification as opposed to the presence of deeper hummocky cross stratification, at each one of the studied sections. Finally, the data present suggest that long lasting fair weather conditions are not as frequently recorded as the storm-deposited sequences from shore-face to offshore in nearshore environments.
