This is a partially developed activity description. It is included in the collection because it contains ideas useful for teaching even though it is incomplete.

Correlating building stone type with building age to introduce the concept of dating rocks using index fossils

Contributed by: Wayne Powell, Brooklyn College
Topics: building stones, rocks, rock properties, correlation, relative and absolute dating, index fossils, geologic history
Course Type: introductory level
This activity is designed to motivate and engage urban students.
This activity utilizes the unique resources of an urban setting.
This activity draws connections between geoscience and non-science topics (e.g., culture, politics, history, art, forensics, etc.)


In many major cities, stone used for buildings changed over time as transportation routes evolved and different sources became both available and economical to use. Architectural style also changed over time. Someone who knows how to identify specific building stones and architectural styles in New York City, for example, can infer a time range for construction of a building by knowing something about the evolution of architectural styles and the time period at which particular building stones became available. Developing a field trip activity that goes beyond simply identifying building stones and their properties could give students experience in an activity that has direct analogs with using index fossils to date rock units and evaluating changes in rocks over time. It might even be possible in some cities or portions of cities to create inferred building age maps based on architectural style and stone type that would have analogs with geologic maps. This could give students experience in interpreting the history of development of a city that could have some analogs with the geologic history of a region.


-students practice rock and mineral identification.
-students apply what they have learned about using "index stones" for determining an age range for buildings to using index fossils for determining an age range for rocks.
-if possible, students would apply what they have learned about the process of determining building history to determining geologic history of an area.


depends on the way the activity were designed, but you'd want to make sure that they could articulate the analogy between the historical problem and the the geologic problem and to be able to do both the historical and the geological age interpretation on their own with an unfamiliar example.