This oil field is a Sadlerochit formation described as a delta and braided stream sequences bounded by unconformities and derived from a Permian and Triassic mountain range north of the field.

This oil field is a Sadlerochit formation described as a delta and braided stream sequences bounded by unconformities and derived from a Permian and Triassic mountain range north of the field.

• A. Kuparuk Field
• B. Forties Field
• C. Ghawar Field
• D. Prudhoe Bay Field

Answer: (D)

Understanding how sedimentary environments record their source and history helps identify the field. The Sadlerochit Formation in this region is known for delta and braided-stream sandstone deposits that are bounded by unconformities, indicating distinct sedimentation episodes separated by breaks in time. The sediments are sourced from highlands to the north during the Permian–Triassic, transported south into a foreland basin. That combination—coarse, well-sorted sands from a northern mountain belt, deposited in a deltaic to braided-stream setting and separated by unconformities—points to Prudhoe Bay Field on Alaska’s North Slope. Other fields come from different basins and have different depositional histories (for example, Forties in the North Sea, Ghawar in Saudi Arabia, and Kuparuk with a different North Slope stratigraphy), so they don’t match this particular formation and setting.

Understanding how sedimentary environments record their source and history helps identify the field. The Sadlerochit Formation in this region is known for delta and braided-stream sandstone deposits that are bounded by unconformities, indicating distinct sedimentation episodes separated by breaks in time. The sediments are sourced from highlands to the north during the Permian–Triassic, transported south into a foreland basin. That combination—coarse, well-sorted sands from a northern mountain belt, deposited in a deltaic to braided-stream setting and separated by unconformities—points to Prudhoe Bay Field on Alaska’s North Slope. Other fields come from different basins and have different depositional histories (for example, Forties in the North Sea, Ghawar in Saudi Arabia, and Kuparuk with a different North Slope stratigraphy), so they don’t match this particular formation and setting.