Archaeometry of ferrous artefacts from Luso-Brazilian archaeological sites near Ipanema River, Brazil

Abstract

The present investigation analysed iron artefacts collected in two sites around Araçoaiaba Hill. A known methodology was adapted to investigate several samples collected at the Royal Iron Factory of São João do Ipanema and Sardinha sites. EDX microanalysis results of non-metallic inclusions were plotted in bivariate graphs. Linear regression (with and without the zero-intercept constraint) and line intercept significance tests were applied to interpret these results. The analysis did not allow the identification of the provenance of the production systems of Sardinha and Ipanema sites. The presence of Ti-rich inclusions was an unambiguous attribute of the samples collected at the Sardinha site.

Investigating the Provenance of Iron Artifacts of the Royal Iron Factory of São João de Ipanema by Hierarchical Cluster Analysis of EDS Microanalyses of Slag Inclusions

“…All samples showed the presence of dendritic wustite (FeO) phase inside the slag inclusions, which is compatible with the high FeO content in the inclusions (Table 2). These values were similar to the values observed in the archaeometallurgical literature [7][8][9][10][11][12][13][14][15][16] . High FeO content in the slag is usually associated with the oxidizing conditions in the refining step of the indirect process, when the high carbon content of the pig iron must be oxidized.…”

“…In this sense, the chemical composition of these slag inclusions is defined by the composition of the different materials and raw materials used during the manufacturing process, such as iron ore, charcoal ash, furnace lining, fuel, hearth lining, fluxes and etc. The investigation of the chemical composition of slag inclusions in ancient ferrous artifacts has been used to determine some technological and historical characteristics of the metallurgical processing, including their possible provenance [7][8][9][10][11][12][13][14][15][16] . In 2007 Dillmann and L'Héritier 7 presented a methodology applying data processing on the EDX microanalyses of slag inclusion of 170 ferrous objects sampled from several archaeological sites and monuments.…”

“…Maia et al [14][15][16] investigated by EDX microanalysis the slag inclusions of ferrous objects collected from the Royal Iron Factory of São João de Ipanema and Afonso Sardinha archaeological site. The authors questioned the effectiveness of the linear regression method (passing through the origin), which had been proposed by Dillmann and L'Héritier 7 to determine the signature of the production processes, but they did not investigate other methodologies [10][11]13 to obtain the signature of the production processes of Ipanema and Sardinha.…”

A late medieval or early modern light gun barrel from the Castle Museum in Malbork—typology, technology of manufacture and identification of the smelting process

“…10; for other works where this method was used, see, e.g. Mamani-Calcina et al 2017;Maia et al 2015;L'Héritier et al 2013; for earlier attempts at discriminating between both processes, see, e.g. Buchwald and Wivel 1998: p. 87-91, Tab.…”

Microanálise De Inclusões Não Metálicas De Artefatos Ferrosos Da Fábrica De Ferro De Ipanema Visando Estabelecer a Assinatura Química Do Seu Processo Produtivo

“…Eles aplicaram "análise de regressão logística" dos resultados de microanálise das inclusões para distinguir as peças ferrosas produzidas pelos processos de redução direta e redução indireta, e o método de análise multivariante para identificar a assinatura do processo produtivo dos artefatos ferrosos coletados nas catedrais góticas Francesas. Em 2015 Maia et al [10][11][12] analisaram por microanálise EDS as inclusões não-metálicas de objetos ferrosos coletados na Real Fábrica de Ferro de São João do Ipanema e no sítio de Sardinha. Foram construídos gráficos bivariantes da porcentagem de alguns óxidos presentes nas inclusões, como proposto por Dillmann e L'Héritier [3].…”