Maya Metallurgical Technology in Late Postclassic-Spanish Colonial Times: The View from Lamanai, Belize

Recent archaeometallurgical studies at the ancient Maya site of Lamanai, Belize have begun to reveal the nature of copper metallurgy in the centuries just prior to and during Spanish contact in the Southern Maya Lowland Area. More copper artifacts have been recovered from controlled archaeological excavations at Lamanai than at any other site in the Southern Maya Lowland area. A total of 187 copper objects dating to the 12th through 16th centuries AD have been recovered; among these objects are ingots or pigs, blanks, prills and a substantial number of mis-cast objects, many of which are bells. The archaeological contexts in which copper bells, axes, needles, fish hooks, rings, and clothing ornaments have been recovered will be summarised. Forming technologies used in the creation of Maya copper artifacts as well as their chemical compositions were studied using scanning electron microscopy and optical light microscopy. The results of chemical compositional and microstructural analyses will be presented and discussed in the contexts of larger social and economic spheres that were part of the Maya world just before and during Spanish contact in Belize.De récentes études concernant l’archéométallurgie sur l’ancien site maya de Lamanai, Belize ont permis de révéler la nature de la métallurgie du cuivre des siècles avant et pendant la période de contact espagnol dans la zone sud des basses terres mayas. Le nombre d’artéfacts en cuivre découverts lors de fouilles archéologiques contrôlées à Lamanai dépasse tout ce qui a été mis au jour dans les autres sites localisés dans la même région. Un total de 187 objets en cuivre datant des xiie jusqu’au xvie siècle de notre ère ont été découverts. Parmi ces objets on retrouve entre autres des lingots ou barres en cuivre, des douilles, sphérules ainsi qu’un certain nombre d’objets mal moulés, lesquels sont principalement des cloches. Les contextes archéologiques dans lesquels les cloches en cuivre, haches, aiguilles, hameçons, anneaux ainsi que les ornements pour vêtements ont été découverts seront brièvement expliqués. Les moyens technologiques utilisés dans la création d’artéfacts mayas en cuivre tout comme leurs compositions chimiques ont été étudiés par microscope électronique à balayage ainsi que microscope optique. Les résultats des composants chimiques et analyses microstructurales seront présentés et expliqués dans les contextes plus larges des sphères sociales et économiques qui faisaient partie intégrantes du monde maya avant et pendant les contacts espagnols au Belize

Obtaining cross-sections of paint layers in cultural artifacts using femtosecond pulsed lasers

Recently, ultrafast lasers exhibiting high peak powers and extremely short pulse durations have created a new paradigm in materials processing. The precision and minimal thermal damage provided by ultrafast lasers in the machining of metals and dielectrics also suggests a novel application in obtaining precise cross-sections of fragile, combustible paint layers in artwork and cultural heritage property. Cross-sections of paint and other decorative layers on artwork provide critical information into its history and authenticity. However, the current methodology which uses a scalpel to obtain a cross-section can cause further damage, including crumbling, delamination, and paint compression. Here, we demonstrate the ability to make controlled cross-sections of paint layers with a femtosecond pulsed laser, with minimal damage to the surrounding artwork. The femtosecond laser cutting overcomes challenges such as fragile paint disintegrating under scalpel pressure, or oxidation by the continuous-wave (CW) laser. Variations in laser power and translational speed of the laser while cutting exhibit different benefits for cross-section sampling. The use of femtosecond lasers in studying artwork also presents new possibilities in analyzing, sampling, and cleaning of artwork with minimal destructive effects