THE GEOCHEMICAL ASSESSMENT OF POTENTIAL PETROLEUM ACCUMULATION IN LIVINGSTONE BASIN (KARONGA) MALAWI

The geochemical assessment of potential petroleum source rock is very crucial step in petroleum exploration, since it helps to determine the potential petroleum accumulation in different areas. It facilitate key decision on whether further stages of exploration can be carried out.

This paper has described the assessment of the potential petroleum accumulation in Livingstone basin in Karonga Malawi. The Livingstone basin is a rift basin located in Malawi, Africa. It is part of the east African rift system, which is a zone of active tectonic extension. The basin is approximately 300km long and 100km wide and it is filled with a thick sequence of sedimentary rocks that are up to 10km thick.

The Livingstone basin was formed during the Miocene epoch, approximately 10 million years ago. The formation of the basin was initiated by the rifting of the African continent which was by the movement of Nubian plate away from the Somali plate.

The study methodology includes TOC and Rock eval Pyrosis analysis and it involves the geochemical parameter (TOC, HI, OI, S1, S2 etc.) These parameters helped to classify organic matter richness, kerogen type and their thermal maturity level of hydrocarbons present in collected samples.

It was discovered that the Livingstone Basin has TOC values ranging from 2.29 to 3.80 weight percent, and HI values of 120-270 mgHC/gTOC. These results indicate a very good source rock potential, with type II kerogen and early mature to mature organic matter.

The geochemical assessment of potential petroleum source rock is very crucial step in petroleum exploration, since it helps to determine the potential petroleum accumulation in different areas. The basin is approximately 300km long and 100km wide and it is filled with a thick sequence of sedimentary rocks that are up to 10km thick. The formation of the basin was initiated by the rifting of the African continent which was by the movement of Nubian plate away from the Somali plate. The study methodology includes TOC and Rock eval Pyrosis analysis and it involves the geochemical parameter (TOC, HI, OI, S1, S2 etc.) These parameters helped to classify organic matter richness, kerogen type and their thermal maturity level of hydrocarbons present in collected samples.

The Livingstone Basin is a sedimentary basin located in the northern region of Malawi, on the western shores of Lake Malawi. It is a rift basin that is part of the East African Rift System. The basin is about 100 kilometers long and 20 kilometers wide (Macgregor, 2015b).

The Livingstone Basin is bordered by the Livingstone Fault to the east and the Karonga Fault to the west and it is filled with a thick sequence of sedimentary rocks, including sandstones, shales, and limestones. These rocks were deposited in a lake environment over a period of millions of years (Accardo et al., 2018b).

The geological history of the Livingstone Basin is complex and spans millions of years. The basin began to form during the Jurassic period (201-145 million years ago), when the East African Rift System began to develop. The basin was initially filled with volcanic rocks, but these were later covered by a thick sequence of sedimentary rocks that were deposited in a lake environment (Scholz et al., 2020b).

Livingstone basin is considered to be the most promising basin in Malawi for petroleum exploration since it has a number of geological features that are favorable for the formation and accumulation of oil and gas, which includes: thick sedimentary rocks with porosities and permeabilities that are suitable for hydrocarbon storage, Source rocks that are capable of generating oil and gas, Reservoir rocks that are capable of trapping oil and gas, Cap rocks that are impermeable to oil and gas, preventing them from escaping and Structural features that can create traps for oil and gas just to mention a few (Mineral Potential of Malawi, n.d.).

The Livingstone Basin is also home to a number of hot springs and geothermal vents, these features indicate that the basin has a high geothermal gradient, which can help to mature source rocks and generate oil.

District: Karonga

Coordinates: -10.03785, 34.02285