Nuevas aportaciones auríferas y arqueológicas en el área Pinalejo-Tenebrilla (El Maíllo, Salamanca)

Abstract

The Pinalejo Tenebrilla area, located to the southwest of the municipality of El Maíllo (Salamanca), has exceptional characteristics in terms of the influence of gold transport in a river course, as it has two types of gold deposits closely associated with Roman mining workings from the High Imperial period: 1) a quartz seams gold deposit located at the head and on the left bank of the Pinalejo-Tenebrilla stream, where three underground mining workings are located and 2) a Quaternary placer type deposit represented by the stream itself, where relics of its whasings are shown (Ruíz del Árbol, 2001; Sánchez Palencia, 2012). The work consisted of carrying out a morpho-textural and geochemical (scanning electron microscopy) comparative study between the particles of the riverbed and those of the quartz seams of the same area and the description of new elements of the mining environment that enrich the archaeological knowledge of the mining exploitation. The results of the work have revealed a scarce fluvial transport, evidence of the existence of two different input zones, one related to the localised Roman underground workings and the other unknown. A bimodal Au:Ag, chemical composition, where the quartz seams gold presents an average composition of 98% wt Au and the stream particles between 88 and 98% wt Au (related to the quartz seams gold) and < 85% wt Au, related to the distinct source. The discovery of a multiple impact mortar and a granite mill which together with the granulometry of the waste heaps suggest an in situ pre-selection of the material extracted in the mine, its subsequent crushing in the working areas and recovery of the gold in the stream by washing the crushed material.