For all the above prospects, gas prone shales of the mid Jurassic to early Cretaceous Verrill Canyon Formation are the interpreted source rocks. The gas generated from these intervals is believed to have migrated along fault planes until it was trapped in the above structures. The number of significant and commercial discoveries in the Sable Subbasin, sourced from Verrill Canyon shales, clearly demonstrates the effectiveness of these source rocks. The Play Fairway project modeled the maturity of five different aged potential source rocks on the Scotian Margin: Pleinsbachian, Callovian, Tithonian, Valanginian and Aptian. The resulting transformation ratio maps for four of these source rocks (the Pleinsbachian source rock is over-mature in this area and therefore not shown) are found in figures 38, 39, 40, 41. For more information regarding these source rocks and their maturation history consult Chapter 4 of the Play Fairway Atlas.