Sierra El Aliso

Sierra El Aliso is a mountain range in the state of Sonora, Mexico.

Location
Sierra El Aliso is 186 km east-southeast of Hermosillo. The municipality of San Javier is located in the extreme southwest of the Sierra El Aliso, 25 km west of the Yaqui River. The Sierra El Aliso is adjacent to the Sierra de San Javier. Both lie in the Barranca Basin. An unnamed high point in the Sierra el Aliso has a prominence of 760 m and elevation of 1380 m, and is isolated by 24.72 km from Las Tierras South, to the northeast.

Environment
The climate is hot and very humid, with summer temperatures often higher than 40 C. Most of the rainfall occurs in July, August and September. At higher elevations the range holds oak and pine trees, while lower down there is underbrush, some cacti, grass and small shrubs. The sierra contains the village of San Antonio de la Huerta, with about 500 people in 1990, mostly engaged in mining, cattle ranching and agriculture. Of these, mining is the main occupation.

Geology
The Sierra El Aliso is near the center of the Mojave-Sonora Megashear, where both deep water Paleozoic deposits and miogeoclinal shelf facies are found. During the Paleozoic huge volumes of sediments accumulated in deep basins beside the western margin of the North American continent, and were then deformed and thrust faulted against miogeoclinal shelf rocks of the continent during the Antler and Sonoma orogenies. The Sierra El Aliso is composed of assemblages of Paleozoic origin, with less significant volcanic rocks of Triassic and perhaps Cretaceous-Tertiary origin. Middle Mississippian fossils in the Sonora allochthon have been found in the Sierra El Aliso. Possible Early Pennsylvanian foraminifera were also found. An assemblage of conodonts from late Meramecian to early Chesterian would have formed in deep water.