A Magnetic Survey Over La Maja, an Archaeological Site in Northern Spain

Abstract

A Roman archaeological site in northern Spain (La Maja, province of La Rioja) includes pottery workshops, part of an important ceramic industry that developed from about the first century BC to the first century A D . A geophysical study was planned to determine the extent of the industrial complex in the vicinity of an excavated kiln. Magnetic observations were done on a grid of 30 x 36m, with a sampling interval of I m. Two dipolar-shaped anomalies were found: one in the north-east and the other in the south-west of the area. Low-pass and band-pass filters were used in the Fourier domain to enhance the characteristics of the magnetic data and to remove noise and undesirable shallow features. Three-dimensional polygonal prisms were used to model the magnetic anomalies based on palaeomagnetic measurements performed over an uncovered kiln that helped to constrain the induced and remanent parameters of the magnetizing fields.

Geophysical study of a Pre‐Hispanic lakeshore settlement, Chiconahuapan Lake, Mexico

“…The magnetic map in general contains a high degree of noise perhaps due to shallow heterogeneities in the subsoil, such as exposed basalt stones or pottery fragments, which are commonly found in archaeological sites. In order to isolate the dipolar anomalies and to reduce the noise level, a spectral analysis (Spector and Grant, 1970;Chávez et al, 1995) was applied to delimit the wave number interval of interest and to eliminate the noisy portions of data collected within the studied area ( Figure 4).…”

Geophysical methods employed in urban archaeology prospecting: the Basílica de Nuestra Señora de la Salud, Patzcuaro, México

“…Como ya se ha comentado anteriormente, ello es debido a que el sensor inferior estaba situado a un metro sobre el suelo, altura mayor de la que se suele emplear en arqueología (de 0,3 m a 0,5 m, Cámara 1989;Chávez et al 1995), a fin de eliminar ruidos de tipo ambiental. Es posible que, por la posición del sensor, se hayan podido atenuar las anomalías debidas a estructuras de interés más superficiales y que aparecen reflejadas en el nivel 2 de GPR (letra A).…”

“…Hay que señalar que los métodos geofísicos no destruyen el contexto histórico (Scollar 1986) y se ha mostrado su utilidad en la definición y caracterización en sitios de interés arqueológico Chávez et al 1995). En zonas urbanas, que poseen un contexto arqueológico, generalmente es imposible llevar a cabo una excavación; la realización de estudios geofísicos permite cartografiar esta riqueza arqueológica y así conocer y proteger el Patrimonio Arqueológico ante futuros cambios urbanísticos.…”

Joint geophysical measurements to investigate the Rossano of Vaglio archaeological site (Basilicata Region, Southern Italy)

“…In this framework, the most suitable geophysical investigation techniques employed for archaeological purposes are the magnetic method (Bates and Bates, 2000;Bavusi et al, 2004;Chavez et al, 1995Chavez et al, , 2001Godio and Piro, 2005;Powell et al, 2002), the geoelectrical method (Cammarano et al, 2000;Di Fiore and Chianese, 2008;Rizzo et al, 2005;Sambuelli et al, 1999;Tsokas et al, 1994) and the GPR method (Basile et al, 2000;Chadwick and Madsen, 2000;Chianese et al, 2004;Masini et al, 2007;Perez Garcia et al, 2000;Sambuelli et al, 1999;Savvaidis et al, 1999;Tsokas et al, 2007). In fact, they provide non-destructive and broad range of application means of exploring for the archaeological purpose, especially because they are noninvasive and prompt techniques.…”