Anticline trap
Topic: Energy Resources of India: Conventional and Non-conventional · NCERT: Class 10, Ch 5 "Minerals and Energy Resources"
Meaning
An anticline is an upfold, where rock layers bend upwards like an arch or dome. An anticline trap is that upfold when oil and gas collect at its top. They sit in porous rock such as limestone or sandstone, which has tiny spaces that can hold fluids. Non-porous layers above and below seal the oil in, so it cannot escape. Gas is lighter, so it sits above the oil, and the oil sits above the water. Many of the world's oilfields are found in these traps.
Example
India's oilfields occur in Tertiary sedimentary rocks. Fields such as Ankleshwar in the Cambay basin of Gujarat hold oil in folded and faulted rock structures of this kind.
Don't confuse with
- Fault trap: oil is held where porous and non-porous rocks meet along a fault, which is a crack where rocks have moved. An anticline trap is made by folding, not by a crack.
Related concepts
- Petroleum
- Oil and Natural Gas Commission
- Digboi oilfield
- Naharkatiya oilfield
- Cambay basin
- Mumbai High
- Barmer oil fields
- Krishna-Godavari basin
- Field-based and market-based refineries
- Strategic Petroleum Reserve