Equatorial Atlantic (EA) Post-Rift Phase

A second passive margin sequence developed along the Suriname margin. The late Albian caps the syn-rift deposits and marks the transition to post-rift sedimentation. A passive margin undergoing thermal subsidence developed. Tectonically, this period represents the end of mechanical rifting on the margin, and the creation of oceanic crust further seaward (Edge, 2014).
During the Cenomanian and Turonian, Africa is moving away in N 70° direction along transform systems. The continued sea level rise resulted in the deposition of the marine shales, known as Canje source rock.
From the Campanian onwards, Africa is moving away in N 90° direction. In general, the falling sea level was causing major incisions on the Shelf leading to large amounts of late Cretaceous sediments to be deposited into the Deep Basin by large canyon systems such as the proto-Berbice and proto-Corantijn rivers (and probably other Suriname river systems). Yang et al., 2011 noted that the Guiana shield supplied sediments to the Atlantic Ocean during this period. The large amounts of sediment deposition resulted in rapid subsidence that could have led to major maturation of the deeper Cretaceous source rocks.

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Since the late Cretaceous, the coast of Suriname has remained a passive margin. Paleogene marine flooding shales were deposited, known as the “Top Paleocene-Eocene MFS” playing an important role in the onshore trapping mechanisms. At the end of the Eocene a regression cycle starts leaving behind the well-known Top Eocene Unconformity picked in the onshore wells. These shales compliment the further subsidence of the Basin.
Hoorn et al., 2010 notes the rise of the Andes starting at 65 Ma eventually resulting in the onset of the Amazon fan at approximately 10 Ma. An increase of Andean-derived sediments due to the Andean uplift and erosion, and erosion of the Guiana shield resulted in a large sediment progradation in the Basin. These clay-dominated sediments contributed to subsidence and maturation of the Canje (ACT) SR and the end of carbonate growth on the shelf,
, which also ended the carbonate growth on the shelf.

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