Order Rock Events Using Cross Cutting

Begin with the geologic time terms passage, then apply the rules on the cross section sheet. Use the Grand Canyon and glacier sheets to connect the rules to real places.

Trace an unconformity and order 11 rock units, a fault and a dike from oldest to youngest. The directions on the page read: Use the rules to read the cross section. Trace the unconformity and label it U. Then write all 11 letters, including U, in order from oldest to youngest. An answer key is included.

Yes, both. We made it for 8th grade Earth science, and it works the same at home or at school. At home, a student can work through it alone and then go over it with you, which shows quickly what is solid and what needs another look. In class it works as independent practice, homework or a warm-up, and you can print one copy or a full set.

An unconformity is an old erosion surface where rock wore away before new layers formed on top. It marks a gap in the rock record. At the Grand Canyon's Great Unconformity, rock once above the Vishnu Schist was worn away.

A fault, dike or channel is younger than every rock it cuts. Geologists use this with superposition to put events in order. Order Rock Events Using Cross Cutting has students order 11 letters from oldest to youngest.

Glaciers carve cirques, horns, aretes and U-shaped valleys, and they drop moraines, erratics and outwash plains. Kettle lakes form where buried ice melted. The glacier sheet sorts nine landforms into erosion and deposition.