The Paleogeography of Paleozoic and Mesozoic Storm Depositional Systems

Present-day hurricane belts are confined to 5°-45° latitude along the western edges of oceans, whereas winter storms occur ubiquitously above 25° latitude. Both hurricanes and winter storms occur between 25° and 45° latitude in some areas. Storm zones can be identified on global paleogeographic maps with the assumption that this latitudinal zonation of storm systems existed in the geological past. Evaluation of 69 previously-recognized Paleozoic and Mesozoic storm depositional systems on such maps showed that only 70% of them occur in ancient hurricane, mixed hurricane and winter storm, and winter storm belts. The remainder occur on the western sides of continents and/or at low paleolatitudes, and therefore well may be of different origin. Mesozoic storm depositional systems containing hummocky stratification tend to occur in counterpart paleo-winter storm belts, whereas hummocky stratification in suggested Paleozoic examples occur in both winter storm and hurricane belts and in paleolatitudes where we infer storm activity did not occur.