An offshore prograding sand sea exists along portions of the Arabian Gulf coastline near Dhahran, Saudi Arabia. Sediments of eolian dune, interdune, sand sheet, and siliciclastic sabkha intercalate with marine deposits. Strong offshore winds supply abundant sand to the coastline, and cause at present time the outbuilding of the dune system. The broad intercalation of eolian and marine deposits which results creates ideal potential for subregional stratigraphic petroleum traps, due to pinch-out of porous and permeable dune sands into impermeable marine mudstones. Within the eolian system itself are potential reservoir rocks (dunes), sources (organic-rich sabkha and interdune deposits), and seals (zones of early cementation in all deposits). Early cementation is very common in all facies. The early cementation occurs owing to (1) soil formation, (2) deposition of pore-filling gypsiferous cements from saturated solutions near water table, and (3) addition of sand-size windblown evaporitic material to sands downwind of sabkhas.--Modified journal abstract.