Fig. 9

a Core photograph showing rhythmic layers of sand and mud. Middle Pleistocene, Gulf of Mexico; b Core photograph showing discrete thin sand layers with sharp upper contact. Traction structures include horizontal laminae, low-angle cross-laminae, and starved ripples (arrows). Dip of cross-laminae to the right suggests current from left to right. Note rhythmic occurrence of sand and mud layers. Middle Pleistocene, Gulf of Mexico. Source: a- From Shanmugam (2012a). b- After Shanmugam et al. (1993), with permission from AAPG