There are six major and two minor endogenous domes, as well as flows comprising light-ash perlitic lava that originate from the former. They occupy the western half of the caldera depression; they constitute the SW part of the volcano slopes.

The presence of acute spines and scoriaceous surfaces, the lack of soil cover and the smaller quantities of lateral scree deposits imply that the lava domes and flows of Mporiatiko (NE) and Karaviotis (SW) are the newest volcanic edifices of Nisyros.

The presence of a high percentage of andesitic magma enclaves (up to 15%) is remarkable; their sizes vary from microscopic to 0.5m. Percentage of inclusions is in inverse proportion to the age of domes.

This has directly influenced the overall chemical composition of the rock, and the composition of lavas varies from rhyolitic to dacitic.