Abstract

BARRERA R., Rosier Omar. Geomorphological considerations about the Sierra Madre Occidental in Northern Jalisco, México. Invest. Geog [online]. 2002, n.48, pp.44-75. ISSN 2448-7279.

This analysis of the geographical space focuses on Geomorphology, a science that deals with the genesis and evolution of landforms. This definition includes two basic elements: relief and form. The former results from geological processes, and the latter from morpho-clilmatic processes. This work derives from the need to communicate the features of landform structures located at the northern portion of the Jalisco state, the main attributes of which including block tectonics, arisen from an extensive area affected by volcanic activity during the Mild Cenozoic. Tectonics respond to core movements generated, according to the pilate tectonics theory, during the Upper Tertiary and Pleistocene, and which have affected this area as a result of the proximity of subduction zones. Lava deposit blocks along with ancient volcanoes have jointly formed wide plateaus denominated riolithic plateaux in the field of structural geomorphology. Landform structures provide the basic element upon which exogenous or morpho-climatic forces work, thus modeling the relief's sculptural forms. Interfluvial and slope modeling are characterized by the specific dissection of tropical zones; separately, chemical processes originate ferruginous soils and water runoff travels down ravines seeking the water table at the bottom of deep canyons limiting plateaux. Henece edaphogenetic processes dominate at fiat interfluvial areas, whereas displacement of detritic materials prevail along slopes and fluvial terraces at the bottom of valleys.

Keywords : Landform structure; block tectonics; riolithic plateau; morphogenesis; morpho-climatic processes; dissection.