Archeointensity results from El Papalote and Casas de Fuego furnaces, Chihuahua state, northern Mexico - HAL-SHS - Sciences de l'Homme et de la Société Accéder directement au contenu
Poster De Conférence Année : 2019

Archeointensity results from El Papalote and Casas de Fuego furnaces, Chihuahua state, northern Mexico

Résumé

Despite the rich archaeological heritage of Mexico, the local secular variation curve of the Earth's magnetic field is still inaccurate, especially because of a lack of intensity data in the northern part of Mexico. We will present new archaeomagnetic data from a ceramic production area, the archaeological site of Casas de Fuego, located about 16 km SE of Paquime, Chihuahua State, Mexico. Very unusual, well preserved rectangular furnaces, composed of mud and stone, have been excavated. They measure on average 3 by 2 meters with an approximate height of 1m, and the walls and floors were burned. An earlier analysis of the site (Carlos Cruz-Guzman and Iveta Nava Maldonado, PhD INAH, 2008) reveals that the occupation took place during the middle period of the Mogollon culture (1250-1450 AD). Also, the deformation of clay and slag suggests exposure at temperatures above 1200° C, particularly favourable for archaeointensity analysis. Nine chambers were sampled (4 to 8 blocks per room): one in a small site called El Papalote (30.2828°N, 107.9015°W), located about 7 km from the main site of Casas de Fuego (30.2047°N, 107.8874°W), and eight chambers at two Casas de Fuego sites. 186 cubic specimens were used for the analysis (between 16 and 25 specimens per chamber) of which 80 for the paleointensity determinations on these cooling units. Rock magnetic experiments, mainly K/T curves, FORC diagrams and magnetic coercivity spectrum, indicate that Ti-poor titanomagnetite is the main carrier of magnetization, with usually a good thermal stability. Well-defined mean characteristic magnetization directions were obtained for each block, mainly after AF demagnetization, but some statistically different directions were observed. Archeointensity estimates were obtained using the classic Thellier-Thellier protocol with anisotropy and cooling rate corrections, with a success rate of 66%. Paleointensity values range from 50 to 69 μT. The differences seen as well in direction than in intensity highlight the fact that the period of use of these furnaces was long enough to record variations of the Earth’s magnetic field, a conclusion that will have to be confirmed by radiometric ages. Our new data will be compared to other Mexican data and to data from the southwestern part of the United states of America.
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Dates et versions

insu-02431912 , version 1 (08-01-2020)

Identifiants

  • HAL Id : insu-02431912 , version 1

Citer

Brina Madingou Tchibinda, Mireille M. Perrin, Arnaldo Hernandez-Cardona, Luis Manuel Alva-Valdivia, Gwenaël Hervé, et al.. Archeointensity results from El Papalote and Casas de Fuego furnaces, Chihuahua state, northern Mexico. American Geophysical Union Fall Meeting 2019, Dec 2019, San Francisco, United States. , pp.GP41A-0775, 2019. ⟨insu-02431912⟩
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