The two activities most influencing biological and soil resources are the previous mining and recent exploration, as well as the repeated fires highly altering the vegetation. The soil types are related to rock types and substrates influenced by the topography on and around Soledad Mountain. Six soil series were identified and mapped. The soils have a wide range of textures depending on the parent material and degree of weathering. Soils derived from rock altered by hydrothermal activity have increased clay content.
Textures range from clay loam to fine sand, with a large amount of coarse fragments.
The organic matter content of the soils is very low and variable, and the nutrient status is also low. The soils' physical characteristics and nutrient content are poor as a growth medium for native vegetation. The general lack of soil development and suitable surface horizons are major limitations for soil salvage and potential for use in reclamation. Our recent revegetation testing for reclamation in the deserts of southern California has shown the salvaged desert soils are not a better growth medium than recontoured overburden piles or spent leach heaps . Surface soil on the project site in alluvial areas and residual accumulations on lower slopes and fans contain seed reserves that can be salvaged and stored as a seedbank.