The country has extensive mineral reserves, many of them poorly understood or not exploited, including coal, vermiculite, rare earth elements and bauxite.
The Rusizi-Ubendia orogeny, a mountain building event 1.8 billion years ago in the Paleoproterozoic deformed and metamorphosed the rocks in the north of the country, affecting a large swath of what is now central Africa including southern Tanzania, northern Zambia, Burundi, Rwanda and the Democratic Republic of the Congo.
The event caused regional deformation, metamorphism and igneous intrusions preserved in northern Malawi, Tanzania and Zambia.
[2] As the Mozambique orogeny came to an end, brittle deformation produced phyllonite in older gneisses in northern Malawi.
Throughout the Mesozoic, the basin filled with sediments forming the Karoo Supergroup, the most extensive sedimentary unit in southern Africa.
In Malawi, the Karoo Supergroup deposited between the Permian and the Late Jurassic, creating sequences of mudstone, sandstone, marl and even coal seams.
In the Late Jurassic and Early Cretaceous, carbonatites, feldspar, granulites and feldspathoid syenites intruded, forming the Chilwa Alkaline Province in southern Malawi.
Geologists believe that down-faulting allowed the lake water to flow to lower elevations, extending to Cape Maclear Peninsula.
Although permeability is low, the water is generally good quality except in places where it encounters and dissolves evaporite deposits where it can have high salinity.
Unconsolidated saprolite forms a weathered, unconfined aquifer in Precambrian material between 15 and 30 meters thick in plateau areas.