1. examine record a. use the three basic rules to figure out the ages of the layers. in chart a, list the layers from youngest to oldest with the youngest layer in the first row. 2. look for signs of tilting, erosion, or folding. in the second column in chart a, write whether you think tilting, erosion, or folding took place. write tilting, erosion, or folding next to the letter of any rock layer that was formed when the tilting, erosion, or folding took place. if you see no evidence of tilting, erosion, or folding, write none. 3. repeat steps 1 and 2 for record b. record the data in chart b.