Kerogen is the primary precursor of petroleum. It is a complex organic material found in sedimentary rocks that, through heating and pressure, can convert into liquid hydrocarbons, forming petroleum.
| Column I | Column II | ||
| P. | Malanjkhand | 1. | Uranium ore |
| Q. | Tummalapalle | 2. | Gold ore |
| R. | Bhukia | 3. | Tin ore |
| S. | Tosham | 4. | Copper ore |