Iranian plateau can refer to either a geological formation in Eurasia or a historical region in western Asia home of ancient civilizations.

In Britannica
This plateau in central Iran, Southern, Western and Central Asia, was home of ancient civilizations, and a geological area of Eurasia north of the great folded mountain belts created by the collision of the Arabian plate with the Eurasian plate.
In geology, the plateau region of Iran primarily formed of the accretionary Gondwanan terranes between the Turan platform to the north and the Main Zagros Thrust, the suture zone between the northward moving Arabian plate and the Eurasian continent, is called the Iranian plateau. It is a geologically well-studied area because of general interest in continental collision zones, and because of Iran's long history of research in geology, particularly in economic geology (although Iran's major petroleum reserves are not in the plateau). In addition geologists have been able to use archaeological and historical records of major earthquakes to study the geology of the region due to the length of civilization in the area, and because of the long history of a written language in Persia.
In classical times the region was called Arana(Ariana), meaning "land of the Aryans", which in Middle-Persian was "Eran", which became Iran in English. The old-Persian form of the word was Aryānām Xšaθra.(see also Haryana, Aria and Arran) It is bordered in the east by the Indus and by the Hindu Kush. The northern limit is in central Asia, while the southern edge is at the Persian Gulf and the Arabian Sea. Today the region corresponds to the States of Iran, Afghanistan and Tajikistan, as well as parts of Iraq, Pakistan, Azerbaijan, Turkey, Turkmenistan and Uzbekistan.
The Iranian plateau comprises about 1.45 million square miles (3.7 million square kilometers).