The North Nyasa Alkaline Province
Longitude: 33.92, Latitude: -13.58
Kongwe is an oval ring structure of about 6x4 km the central core of which consists of gneisses with porphyroblasts of microcline perthite, granular sodic plagioclase, aegirine-augite, biotite, garnet, a little quartz and, in some rocks, amphibole.
BLOOMFIELD, K. 1965b. A reconnaissance survey of alkaline rocks in the northern and central regions. Records, Geological Survey of Malawi, 5: 17-63.