Figure 26 is a compilation play map of the Suriname coastal plain, based on observations in the area of the Tambaredjo and Calcutta fields. The entire coastal has access to the Cretaceous marine source rock. Accumulation of hydrocarbons occurred only there where sufficient clay is preserved. These clays are found within the tidal flat settings, away from the river systems. The Paleocene-Eocene sequence is considered the most prolific interval onshore because of its favourable position in the narrow clay dominated depositional belt.
The estuaries (which existed from Palaeocene time onwards) have been indicated in yellow. Note the presence of an extensive carbonate bank offshore. Carbonates persisted through most of the Late Cretaceous and the early Tertiary (Paleogene). After the Miocene the Amazon river probably broke through and the equatorial current started to supply mud along the shore of Suriname, effectively killing off carbonate growth. The carbonates also prevented strong long-shore currents, giving further support to the observation that the estuaries must have been perpendicular to the then existing coast line.
The concept of estuaries, alternating with mud flats is extrapolated to un-drilled areas on the coastal plain. The Nickerie rivers draining the area west of the Bakhuis mountains, explain the sandy nature of the Wageningen wells and the lack of seal. The Corantijn river is also suspected to have been associated with an estuary. In between these rivers, mud flats with tidal inlet complexes are expected. These areas are indicated in green. Within these areas the chance of finding another Tambaredjo-like oil field is considered high.