Abstract

VENEGAS CARDOSO, Francisco Raúl  and  LOPEZ GARCIA, José. Study of some pedogenetic processes in Ojos Negros Valley, Baja California, Mexico. Invest. Geog [online]. 2005, n.57, pp.53-67. ISSN 2448-7279.

Systematic soil studies in Baja California, Mexico, have been poorly developed. At present there are only few reports in the scientific literature, with the main work been performed in the region of el Desierto Central. The proposal of this work is to study the pedogenetic processes that allowed the development of the soils in the Ojos Negros Valley, Baja California, under a Mediterranean environment. The jerarquical method proposed by Zinck (1988) was employed to study the pedogenetic processes. A morphogenetic environment of depositional nature was established. It allowed separating four landscapes: Hills, Piedmont, Base plain level and Fluvial valley. Each one of them was also subdivided by relief/modelling and lithological characteristics, and their corresponding soil units to the level of Great Group, according to the Soil Survey Staff (1992). These soils were formed under different environments, materials, climatic conditions, and with dry and wet glacial and interglacial periods. These processes started since Pliocene and continue at present, noticeable in its pedogenesis. Some soils have developed Bt red horizons over schist and gneiss (Rhodoxeralfs); others were developed over granitic detritus and show a poor development (Xeropsamments). Granitic materials with colluvium-alluvial processes have formed polygenetic soils, horizons C, with the presence of red Bt horizons (4CBt), inheritably clay and amorphous Fe, (Haploxeralfs). Some others manifest Gley influence (Cegz1, Gley1 6/5GY, Fluvaquents). Finally, the processes of erosion, transport, and accumulation of materials in the lowlands continue happening at present, as well as the presence of a relatively new process: materials been redistributed by wind and deposited over meta-rhyolite dikes, provoked by the drought conditions in the entire region.

Keywords : Soils formed processes; soil genesis; sediments; soils of Baja California; Mexico.

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