The rocks in Tovaberget are the same as in the other table mountains: basement, sandstone, alum shale, limestone, clay shale, and dolerite. Both Tovaberget and Myggeberget are sometimes regarded as spurs projecting from Brunnhemsberget. The dolerite is visible at Tovaberget in the form of a precipice 10–15 metres high.
On the western slopes of Tovaberget is a nature reserve, where the limy clay shale favours fertile soils, herb-rich woodland, and lime-loving moss flora close to streams and marshy woodland. In some places where the water is calcareous, we find alkaline fens with a diverse flora.
