Morphologically, Monte Muambe is a ring-shaped feature, composed of Karroo sandstones which rise from peneplain plateau at altitude between 250 m in the south and 300 m in the north.
Due to hardness of altered Karroo sediments, after continuous, long-time erosion, Monte Muambe at present is a well-developed circular ridge (caldera), basin-shaped, and steep-sided with a crater-like depression inside.
[citation needed] The region of Monte Muambe is situated on the southern margin of the Tete gabbro-diorite complex of the Precambrian age, in a depression filled in the Mesozoic by sediments and volcanic activity products of the Karroo System.
These sediments form an east-west trending belt, gently dipping to southeast in the sedimentary formation and volcanic rocks of Monte Muambe area.
Post-Karroo deposits are commonly represented by sandstones and conglomerates with interstratified Mesozoic or younger volcanic rocks.
Alkali lava flows which cover sedimentary sequence forming tabular igneous bodies elongated to south, represented by rhomb porphyry trachytes and hyalotrahytes Summarized the major events and characteristics of Lupata Series their time of extent was from Lower Jurassic to Lower Cretaceous, and from that time Monte Muambe, as a part of volcanic system of the East African Rift, represent carbonatite extinct volcano.
The concave bottom of caldera, about 5 km in diameter, consists of carbonatite, agglomerate, tuff, feldspathic rocks (fenites) and basic dykes.
[citation needed] The central circular part of highly dissected, craggy hills of carbonatite is asymmetrical and about 200 m lower than Karroo ridge.
The carbonatite ring is characterized by vertical scarps on inner side, with surface which often shows irregular knots, nodes, or veins of more resistant (silicate) material.
[citation needed] The bottom periphery of caldera, 0.5 km wide, is mostly built of feldspathic rocks (fenites), and little or no carbonatite.