Evolución granométrica y morfométrica de los minerales pesados con el transporte: sector oeste de la Rivera de la Mimbre (Salamanca)

Abstract

Granulometric parameters of heavy minerals in ephemeral rivers of the western side of Rivera de La Mimbre (Western Salamanca) have had analyzed to ascertain their textural variations from the source rock areas. Percentil and sorting of the heavy mineral fraction evolve very quickly along transport. By the contrary, mean size, median and skewness remain near constant, Percentil values decrease more markedly for higher dense minerals (–ΔΦ for Cassiterite = 1.06 Φ, Monacite = 0.63 Φ, Zircon = 0.61 Φ, Dmenite = 0.46 Φ, Turmaline and Apatite = 0.26 Φ, Andalucite = 0.174 Φ) along the same distance transport (3 kilometers), Sphericity of the heavy mineral remains constant with transport. Roundness is slightly increased in the grains that are more resistant to abrasion (Ilmenite), being this increase more marked in the lower resistant species (Cassiterite).