Throughout the reflection, make sure that you have the copy of the student guide, PDF or Word and your data tables. Complete the paragraph by using the drop-down menus. In this lab, you determined the relative ages of rock layers using the principles of relative dating. The says that a rock layer found closer to Earth’s surface is a rock layer that is deeper in Earth’s surface. The states that intrusions are the rock layer they cut across. You also determined the absolute ages of rock layers using a . The data you gathered helped you identify an unknown fossil.