Oil is found in petroliferous rock. Which one among the following structures demonstrates an ideal trap ?

Oil and natural gas are found in petroliferous rocks, typically accumulating in specific geological structures known as traps. The anticlinal structure is considered the ideal and most common structural trap for petroleum [1]. An anticline is an upfold in the Earth's crust where rock layers are thrust upward into a dome or arch shape [2]. In these formations, oil and gas migrate upward through porous layers like sandstone or limestone until they are blocked by an impermeable cap rock [1]. Because oil is lighter than water, it accumulates at the crest or peak of the anticline, often with gas trapped above it and water below [3]. Approximately 80 percent of the world's discovered petroleum resources are found in such anticlinal traps, making them the primary target for geological exploration. While faults can also create traps, the simple upfold of an anticline provides the most efficient natural reservoir [2].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 27: Fuel and Power > PETROLEUM > p. 268
2. [2] NCERT. (2022). Contemporary India II: Textbook in Geography for Class X (Revised ed.). NCERT. > Chapter 5: Print Culture and the Modern World > Petroleum > p. 115
3. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 8: Energy Resources > Petroleum > p. 9