Over the past 20 years, the Delaware Department of Transportation (DelDOT) has used cutting edge methods to look for and to study archaeological sites in Delaware. One method is analysis of a site’s soil chemistry (also known as soil geochemistry analysis). By specifically looking at the concentration and pattern of certain elements from soil samples taken at archaeological sites, such as calcium, phosphorous, magnesium, potassium, zinc, iron, aluminum, manganese, and others, archaeologists can learn about past site use, locations of former fences and buildings, areas of trash disposal and animal pens, and areas like paths that were kept clean of debris. Soil chemistry analysis has been used by archaeologists since the early 20th century, and has gained much popularity as a useful tool since the 1990s. Richard Grubb & Associates (RGA) has been given a special opportunity to look at soil chemistry studied at archaeological sites in Delaware dating between the 18th and 19th century. The data will be summarized in a detailed report to DelDOT. Over the next two years, RGA’s monthly blogs will talk about the soil chemistry at numerous archaeological sites in Delaware, the different analysis methods used, and what can be learned from each element. The next blog will discuss the history of soil chemistry on archaeological sites. Stay tuned!