Click area of M Wx (Middle Wilcox, South Texas), Hackberry, or Abbeville to open image of cross-section from respective area.

Figure 9. Map of the northern Gulf Coast Basin showing selected erosional features. Those which are considered to be retrograde failed shelf margins are the middle Wilcox of south Texas, Yegua/Cook Mountain and Hackberry of southeast Texas and southwest Louisiana, Abbeville Lower Miocene of south Louisiana, and Neogene features on the Texas shelf. References are shown in Figure 10.