“What Can the Geochemistry of Bricks Reveal about Historical Archaeology?”
with David Walker
Originally presented 10 Mar 2018
What if someone asked you what was the geographic origin of a brick in an archaeological site? The question of which country constructed specific, early New World settlements might hinge on the answer to this question. The size, shape, markings, and color of the brick may be somewhat informative about the source of the brick. But these are sometimes ambiguous markers of brick provenance. What then? In order to investigate whether trace element signatures might be informative about specific clay deposits that might have been the source of particular bricks, we analysed a range of bricks from both sides of the Atlantic in order to perhaps get a fix on the origin of the brick material in the construction of Fort Sint Kruys in St. Croix, US Virgin Islands.
We found a surprising and profound sameness to the clay-based constituents of Dutch, Danish, and US-sourced bricks of the 17th to 20th centuries. They all look like average continental crust no matter their source, manufacturing admixtures, and state of degradation. We found potential useful markers within the heavy mineral accessories mixed in with the temper sand of all these bricks, but the present state of knowledge is not sufficient to reliably interpret these potentially useful markers for provenance. The zircons, apatites, rutiles, ilmenites and like minerals present an opportunity for further study of the question: “Who built Ft. St. Kruys?”
Dr. David Walker is the Higgins Professor (Emeritus) in the Columbia University Department of Earth and Environmental Science. His main interest lies in the examination of the chemical and physical evolution of the terrestrial planets by methods of experimental petrology. He has a parallel interest in developing new experimental techniques and materials.
PREVIOUS WORKSHOPS BY DAVE WALKER:
SELECTED RESOURCES ABOUT TODAY’S WORKSHOP:
Walker and Bolge (2017) “A geochemical normalization procedure for bricks in historical archaeology”
Love, Serena (2012) “The Geoarchaeology of Mudbricks in Architecture: A Methodological Study from Çatalhöyük, Turkey”
“Bricks, Stones, and Traprocks” in “The Hackensack River–Past, Present, and Future.”
Image created by Kevin Finerghty (Sterling NY) and posted on ESPRIT website with the question ,
“Where does abrasion fall in between weathering and erosion?”