Middle Triassic rocks across the Middle East provide information on regional paleogeography based on the distribution of different depositional facies that are clearly related to the structural history of the region. Several structural provinces have been recognized: the Arabian-Nubian massif, the Middle East platform, and the Tethyan trough.

Except for the central part of interior Syria and central and northeastern Iran, the Middle Triassic rocks of the Middle East represent shelf sediments consisting of three major depositional systems. A belt of mixed clastic-carbonate rocks with evaporite deposits of nonmarine, supratidal, tidal-flat, and lagoonal origin is present in the central part of Saudi Arabia. This belt grades into carbonate-evaporite facies of the Arabian Peninsula, southwestern Iran, northern Iraq, and the area of the Syrian-Turkish border. The carbonate-evaporite facies grades into strata which are predominantly open-marine carbonate rock of the Tethyan sea shelf facies over most of Iran, northern Iraq, most of Syria, probably Lebanon, Jordan, Palestine, and the Sinai Peninsula. Several positive and negative areas are within this platform: the Jawf-Rutbah-Mardin high, the Central Arabian embayment, and the Southeastern Saudi Arabia uplift.

The basinal marine sediments of the Tethyan trough facies include Alpine-Mediterranean deposits in central Syria and a terrigenous flyschlike sequence in central and northeastern Iran. The northeastern to northwestern part of central Saudi Arabia holds promise for new petroleum exploration because of a possible great thickness of Permian-Triassic rocks of the carbonate-shelf facies capped by Middle-Late Triassic evaporites.

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