Una secuencia cratónica del Carbonífero al Pérmico inferior expuesta en los cerros El Tule, noreste de Sonora, México
El Tule hills, located in the northeastern part of Sonora, northwestern Mexico, reveal a predominantly carbonate sequence that ranges from Lower Mississippian to the base of the Permian. The results of lithostratigraphy and biostratigraphy, based on a foraminifer and calcareous algae study, are presented. The following fusulinid zones of Wilde are identified M2, A4, DS1, DS2, MC1/2, VC2/3 and PW1/2. Macrofossils are abundant in the Mississippian and Pennsylvanian limestones but less common in the Permian rocks.
Some comments are added on the genetic and climatic relationships with the cyclothems of Midcontinent of USA and the LPIA (Late Paleozoic Ice Age) glaciation of Gondwana. Supposedly, the palaeoclimate was similar to that of the rest of the Northamerican craton, and it is likely that a local, synsedimentary tectonics dominated in El Tule hills.