Abstract

In the Gulf of Elat (Aqaba) clastics are deposited in alluvial-fan complexes which spill out onto a narrow shelf. Carbonate deposits, including reef complexes, occur along the shelf break. In comparison, along the United States East Coast margin, Triassic to Early Jurassic rifting coincided with carbonate and clastic deposition. The Middle Jurassic and Cretaceous strata reflect the transition from synrift to postrift stages of tectonic evolution. The Gulf of Elat (Aqaba) represents an analogous model for the Early Jurassic East Coast margin of the United States. Beginning in the Middle Jurassic, the East Coast shelf-edge carbonate sequences were being deposited on a passive margin. Carbonate growth may have outpaced subsidence and may be similar stratigraphically to Gulf of Elat (Aqaba) where carbonate deposits are prograding seaward. In the Gulf of Elat (Aqaba), calcium carbonate cementation has significantly reduced the porosity (28%) and permeability (0.01 md) of still-submerged carbonate reefs. However, Pleistocene carbonates on uplifted blocks in the adjacent onshore have undergone leaching and development of secondary porosity as a result of dissolution by meteoric fresh water. The uplifted carbonates contain high secondary porosity (60%) and permeability (10,000 md). In the subsurface, former emergent surfaces are recognized as unconformities. Unconformities in the Mesozoic carbonate rocks of the United States East Coast suggest that potential carbonate reservoirs (one Jurassic and one Cretaceous) formed during periods of subaerial exposure. Hydrocarbons generated during the Early or Late Cretaceous may have moved into the reservoirs prior to deep burial, possibly inhibiting further subsurface diagenesis and preserving the reservoirs.--Modified journal abstract.

You do not currently have access to this article.