Every rock holds clues about how it formed. Geologists are like rock detectives who know how to read the clues about a rock’s origins and the stories it can tell. In this activity, students first become specialists in one type of rock. Then, they meet specialists in other rock types to compare their rocks and teach the others about their rock’s history. This lesson is an opportunity for students to consolidate information from the previous lesson on the rock cycle, and begin to think like geologists. Ideally, the rocks selected for investigation are collected from the site of an upcoming geology field trip – such as to the Caldecott Tunnel or Mount Diablo. In this way, students gain experience identifying individual rocks and learning about the way in which each of the different rock types form. Then, on the field trip, students can apply their controlled classroom knowledge to real world geological history.
Can describe the 3 major types of rock (sedimentary, metamorphic, and igneous) and discuss the relationships between them
Can make careful observations of rocks, including conducting tests for hardness
Can use observations to identify an unknown rock as sedimentary, metamorphic, and igneous
Can describe the geologic processes that formed each of the 3 major types of rock