Hydrogeological study of the Burruyacu basin, Tucuman province, Argentina

A geoelectrical survey (VES) was performed in the Burryacu hydrogeological basin in the northeastern sector of Tucuman Province, Argentina. The area u nder study is bounded on the west by the Sierras de La Ramada and El Cajon, and on the east by Santiago del Estero Province (SEP). The Tajamar River i s the only surface runway in the area; its source is west of the study area on the eastern slope of the mountains. The geoelectrical models, together with data from existing wells, made it possible to identify the permeable z ones. Two aquifer systems have been distinguished. An upper unconfined aqui fer system has sediments with larger grain size in the piedmont zone and th e alluvial fan of Tajamar River, with aquifer levels at depths from 30 to 1 80 m and waters suitable for irrigation. A lower confined aquifer system wi th artesian water is composed of mostly clay layers intercalated with sharp quartzy sands of medium to thick grain size. The sands are well developed throughout the depressed plain and beyond the boundary with SEP. (C) 2001 E lsevier Science Ltd. All rights reserved.