The formation of the Mátra is a consequence of several phases of volcanic activity, which lasted for several million years with long intervals.
The volcanic activities of the first phase are connected to the beginning of the Tertiary period (Eocene), and their relicts can be found on the northern edge of the mountain range. (The mineral resources of Recsk are copper, lead, silver and gold.)
The main mass of the mountain range was formed in the second phase, during Miocene. The volcano must have been 25 kilometres wide and 2000-2500 metres high. The traces of post-volcanic activities in the third phase can be seen on the western and north-western edge of the mountain range. As a result of these post-volcanic activities, an intact lava plateau buried the volcanic formations that evolved earlier in the eastern part of the mountain range and determined the present forms that can be observed in the area of Kékes in the Central Mátra.
In the third phase, ruin volcanos were formed, whose remnants determine the topographical features of the mountain range today (Világos, Tóthegyes, Ágasvár, Muzsla, Sár-hegy).
Since its evolution, the Mátra has almost constantly been eroding, but in varying degrees; the dominating height of its surface is 700-800 metres which is occassionally interrupted by peaks of 850-1000 metres.