Mortar Analysis for Archeological Stratigraphy

The architectural remains uncovered by archaeological excavations offer a unique and invaluable opportunity to analyze early building materials. In particular, the benefits of using mortar to date periods of construction in architectural features have been widely acknowledged in the fields of archaeology and architectural conservation. However, mortars collected as loose fragments from within stratified layers have been generally disregarded. The central aim of this research is to demonstrate that mortars from these contexts are diagnostic artifacts. The mortars in this analysis were excavated from the Stadt Huys Block and Seven Hanover Square excavations in 1980. Together, these sites represent some of the earliest and most continuous history of development in New York City, beginning with the Dutch settlement of New Amsterdam. A study of mortars collected from these sites can supplement information on building practices for a period in which there is little to no extant building stock to reference. Petrographic analysis has revealed distinctive compositional characteristics in historic mortars of the early Colonial Period in New York City. This analysis has also demonstrated how mortar analysis can serve as an additional tool for dating and contextualizing archaeological deposits. This study can serve as a demonstration of how the fields of archaeology and architectural conservation can benefit from the informational resources that they can provide each other.