Resumen de Evidencia geoquímica de un área fuente común para las pelitas del Neoproterozoico Superior-Cámbrico Inferior en las Zonas Asturoccidental Leonesa, Cantábrica y Centro Ibérica.
José María Ugidos Meana, Pedro Barba Regidor, M.I. Valladares
The Upper Neoproterozoic shales of the West Asturian-Leonese and Cantabrian Zones are geochemically very homogeneous and show similar mean contents of Zr, Hf, Nb, rare earth elements, Y, Th, U, V, Cr, Co and Ni and element ratios such as Al2O3/TiO2, Rb/Zr, (La/Yb)n, Th/Yb, Ti/Zr, and Ti/Nb. The Lower Cambrian shales in the same Zones are not as homogeneous although their Al2O3/TiO2, Rb/Zr, (La/Yb)n, Th/Yb, Ti/Zr, and Cr/Zr average ratios are systematically higher, and the Ti/Nb ratio lower; than those of the Upper Neoproterozoic rocks. These distinctive features are coincident with those of the corresponding shales in the Central Iberian Zone. Thus, the geochemical data strongly support the notion that all three Zones shared a very extensive and homogeneous source area.
