The basaltic lavas occur mainly at the rims of and within the rift, mainly at Ma'in area, and along the eastern rim of the rift at Karak, Dana, and Tafila areas. The largest xenoliths occurences are found in the lavas flows and the pyroclastics of the northeastern basalt plataue of Jordan. Most of the xenoliths are rounded and range from 1 to 40 cm in diameter. Field work for the last three years resulted in the collection of about 1000 xenolith samples representing a wide lithological varieties. Xenoliths of this group are the dominant type in Jordan.
Most xenoliths contain primary and secondary phlogopite and hornblende.
The xenoliths are characterized by protogranular and equigranular textures. They consist of olivine, clinopyroxene, orthopyroxene, and brown spinel. Two xenoliths contain garnet beside spinel. The xenolith include wherlite and pyroxenite which are characterized by abundant black and green spinel and garnet. They are characterized by igneous texture and by the presence of abundant spinel and or garnet exsolution blebs as well as broad exsolution lamellae of orthopyroxene in clinopyroxene.