By | May 23, 2015

Objective: To teach the scientific principle of the Law of Superposition and its importance in science.

Standards: Properties of Earth Materials (fossil properties; historical significance), Earth’s History (uniformitarianism and catastrophism; fossils show how life and environmental conditions have changed), Origin and Evolution of the Earth System (geologic dating methods), and Understandings About Scientific Inquiry (scientists use scientific explanations until they are disproved).

Materials: Full laundry basket


(1) At home, fill a laundry basket with various clothes.

(2) Arrange the clothes in layers such that each layer has common characteristics (i.e. color, brand name, clothing type).

(3) Have students remove one piece of clothing at a time, make observations, and record their findings.

(4) Discuss observations and the relevance of the findings.

Science Behind It: The Law of Superposition is a unifying theory in geology and is a crucially important principle in all fields of scientific dating. Things deposited at the bottom of the laundry basket are older and were worn before objects on top of it. Layers deposited during certain time periods usually have similar characteristics and this is used to date events and learn about specific periods in history. Geologists and archeologists use this principle frequently.

Microscopic Creatures in Water