ELECTRICAL RESISTIVITY TOMOGRAPHY 3D STUDY IN PAHNU ARCHAEOLOGICAL SITE, CENTRAL MEXICO

摘要

A Three-dimensional Electrical Resistivity Tomography (ERT-3D) study was carried out at the Pahnu Archaeological Zone, Central Mexico, which has generated important results of great interest to the group of Archaeology in charge of this site. Previous works done on the already excavated pre-Hispanic edifices: the Main Pyramid (MP) and the Tecpan (T) (political and administrative buildings, respectively) have provided of interesting results concerned to their structural stability and interesting features of archaeological importance. However, the archaeological site has not been fully prospected. A couple of mounds have not been yet investigated by the archaeologists, which are probably remains of pre-Hispanic structures. One of such small hills (the southern one, mound E) is investigated in this paper applying ERT-3D methods to characterize the subsoil comprising this feature. This type of procedure has been developed for the last three decades. Traditionally involves the use of quadripole arrays (dipole-dipole) located on parallel lines, which cover the survey area. Different combinations of such arrays are used to acquire enough data to characterize the interior of the mound. The main purpose is to produce clear images of the subsurface structures of interest within the mound's interior. The ERT-3D images obtained show structural characteristics according to the architectural traditions of the pre-Hispanic constructors. The 3D resistivity cube depicts at least two constructive phases, corresponding to different epochs of evolution of that civilization. The information provided by the ERT-3D has been taken into account by the group of archaeology for the new exploration stage in the area, so that they possess sufficient information to begin the rescue of this pre-Hispanic structure.