The Creek of Stinking Water
The name "Yenangyaung" literally means "creek of stinking water," a direct reference to the crude oil that has naturally seeped to the surface here for centuries. This area sits on the Yenangyaung anticline, an elongated, dome-like fold in the earth's crust. This geological structure traps petroleum. Porous sandstones of the Pegu and Eocene rock series, saturated with oil, are folded upwards and capped by impermeable layers of clay and shale, preventing the hydrocarbons from escaping. Over millennia, however, small faults and fissures have allowed some of this oil to migrate to the surface, creating the seeps that gave the area its name and its industry.
In 1855, geologist Thomas Oldham of the Indian Geological Survey was the first to scientifically connect the local practice of digging for oil only on the crest of the hill with the underlying anticlinal structure. This was one of the earliest recognitions of anticlinal theory in petroleum geology. The fold itself is asymmetrical, with the rock layers on the eastern flank dipping at angles up to 40 degrees, while the western flank is steeper, with dips reaching 50 degrees. This entire formation is part of the Salin Sub-basin, a forearc basin that began forming around 40 million years ago, situated between the Rakhine Yoma mountains to the west and a volcanic line to the east.