Chronostratigraphic Correlation Well 5 Well 4 Well 3 Well 2 Well 1 A A A A B B B B C C C C D D D D E E E E F F F F G G H SLIDE 23 Exercise ANSWER – part 2 – the chronostratigraphic correlation The logs were positioned such that the A marker surface is close to horizontal (our datum) Note how intervals from the A marker to the F marker are approximately constant thicknesses The lower part of well 5 and 4 thins dramatically We had a time of regional erosion and possibly tilting Vail et al., 1977b AAPG©1977 reprinted with permission of the AAPG whose permission is required for further use. Courtesy of ExxonMobil L 4 - Well Log Data