Galloway et al. (2000) subdivide phases of buy KD 5170 deposition based on the first downhole appearance of the foraminifer Trimosina A in offshore wells, which is typically dated at ~ 0.6 Ma, and corresponds roughly with the transition from the dominantly ~ 43 kyr to the dominantly 100 kyr Milankovitch forcing: strata below this marker are referred to as the Post Trimosina A (PTA) depositional episode (~ 1.6–0.6 Ma), whereas strata above are referred to as the Post Sangamon (PS) episode (0.6–0.1 Ma). Weimer (1990) further subdivides marine strata in the Mississippi Fan into 17 seismic sequences, of which sequences 1–10 (oldest to youngest) correspond in part to Galloway et al.\'s (2000) PTA, but extend into late Pliocene time; sequences 12–17 correspond generally to the PS depositional episode (Fig. 6). The Mississippi Fan subdivisions of Bouma et al. (1986) ( Fig. 6, Fig. 8 and Fig. 9) are comparable to Resource partitioning of Weimer (1990) ( Fig. 6 and Fig. 10).
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