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Difficulty: MediumMineral Resources and Mining in Africa

Petroleum reserves across major African producing regions, such as the Niger Delta basin in Nigeria and the Sirte Basin in Libya, are predominantly trapped within which type of geological rock formation?

  1. Sedimentary rock strataAnswer
  2. B
    Metamorphic rock formations
  3. C
    Intrusive igneous plutons
  4. D
    Extrusive volcanic basalt sheets

Answer

Sedimentary rock strata
Major crude oil and natural gas deposits in Africa are situated in sedimentary basins (e.g., the Niger Delta, Sirte Basin, and Gulf of Guinea coastal basins) where porous sedimentary rocks like sandstone serve as reservoirs capped by impermeable clay or shale layers.

Step-by-Step Solution

1
Identify the origin of petroleum resources in Africa
Petroleum (crude oil and natural gas) originates from the decay of micro-organisms buried under marine and deltaic sediments over millions of years.
Understanding resource formation pinpoints the host geological environment.
2
Correlate host environments with rock types
Porous sedimentary rocks like sandstone and shale provide both the source beds and reservoir traps for hydrocarbons in basins such as the Niger Delta and Sirte Basin.
Igneous and metamorphic rocks undergo thermal and structural processes hostile to hydrocarbon accumulation.

Key Concept

Geological Host Formations of African Mineral and Energy Resources
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Topics

Mineral Resources and Mining in Africa

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