Mineral and Mechanical Characterization of Earthen Building Materials from Argentina

SPENGLER, GISELA; J. JIMÉNEZ-MILLÁN; CAMPOS-SUÑOL, M.J.; DO CAMPO, M.

Bilbao

Congreso; Reunión Anual de la Sociedad Española de Mineralogía; 2012

Sociedad Española de Mineralogía

The use of sediments for theconstruction of earthen buildings was atechnological development used in everycontinent, from prehistoric times untilthe present. Earthen building techniquesare varied, and they can be classified inthree general types: monolithic systems(rammed earth), brickworks (adobe omudbrick), mixed systems (wattle anddaub) and earthen plasters and mortars.Nevertheless, the recognition ofarchaeological evidence indicative ofthese kind of buildings is problematical,because this kind of architecture isvulnerable to destruction by weathering,especially by wind and water erosion.Rainer (2008) emphasized that, inaddition to environmental variables, thetype of building material is a key factoraffecting their composition anddeterioration. The presence of swellingclays, hydrolytic weathering of minerals,mechanical erosion produced by raindrops, meteo-climatic factors, anddiscontinuities produced by thegeological materials are among themajor causes that produce the physicaland chemical deterioration of theearthen architecture.The determination of texture, plasticityand mineralogy is important tounderstand the behaviour of earthenbuilding materials (Spengler et al.2011). However, detailed mineral andpetrographic investigations on theearthen building materials from Andeanprehispanic cultures are scarces, andover NW Argentine cultures were nevercarried out. The aim of this contributionis to fill in part this gap. A petrographicclassification of the earthen buildingmaterials will certainly contribute tounderstand their weathering and decayprocesses, and to define parameters fortheir determination in archaeologicalcontexts.