Mark's Source in Luke's Gospels

More than half of mark's gospel ends up in luke in one form or another. This means that we can place the composition of mark some time before that of luke, and can we mate how much? Before to assess that, we need to know a little bit about mark's life's story. We first meet mark in acts 12 12, when peter visits the house of mark's mother in jerusalem. In acts 12 25, barnabas and paul take mark with them when they return from jer Jerusalem to their home base in antioch. However, we learn that mark turned back early in the journey; he didn't complete the first missionary journey with them. Thus