Great masses of granite, syenite and diorite were intruded at this period, and send tongues even into the andesitic tuffs.
Subsequently, in the Tertiary period, there were two enormous outpourings of volcanic material - first andesitic lava, and later, after a long interval of quiet, rhyolitic - which nearly half filled the basin, converted it into a plateau and broke up the mountain rim.
The lavas and ashes are for the most part andesitic.
They are often accompanied by volcanic rocks, which are mainly andesitic, and they commonly lie unconformably upon the older beds.
The lavas and ashes which form these cones are mostly andesitic. Mud " volcanoes " occur upon the Makran coast, but it is doubtful whether these are in any way connected with true volcanic agencies.
