The Lut Block (Eastern Iran) extends over 900 km in a north-south direction and is only 200 km wide in an east-west direction. It is confined by the Nayband fault and Shotori Range on the west. The eastern edge is bordered by the Sistan suture zone and Nehbandan Fault. The northern termination of Lut Block is the depression of Kavir-e-Namak and the Great Kavir Fault. The Makran arc, including the Bazman volcanic complex and the Jaz-Murian-Depression, define the southern edge. Sixty-five percent of the exposed rocks within the Lut Block are volcanic and plutonic rocks. Klateh Ahani, Shah Kuh and Surkh Kuh granitoids (Middle Jurassic,165-162 Ma) are among the oldest rocks exposed within the Lut Block. Based on mineralogy, low values of magnetic susceptibility [(1 to 50) × 10-5 SI], and high initial 87Sr/86Sr = 0.7073-0.709, Klateh Ahani, Shah Kuh and Surkh Kuh granitoids are classified as belonging to the ilmenite-series of reduced S-type granitoids. They formed in a continental collision tectonic setting and the magma originated from with the continental crust. The next episode of magmatism was in the Late Cretaceous. Granitoids are reported at three localities with ages within the short time interval between 76.6 to 74 Ma. Based on mineralogy, low values of magnetic susceptibility [(1 to 50) × 10-5 SI], and high initial 87Sr/86Sr = 0.712, the Bajestan granitoid (76.6 Ma) is classified as belonging to the ilmenite-series and the magma was formed in continental collision setting. Gazu granodiorite (75.2 Ma), located near the Nayband fault and within Tabas Block, is calc-alkaline with initial 87Sr/86Sr = 0.7045 that was formed above a subduction zone. Bazman granodiorite (74.2 Ma) is part of the southern Cretaceous volcanic-plutonic belt which was also formed due to subduction. During the Late Paleocene (61-56 Ma) ignimbrites are erupted in Vaghi and Junchi. Based on their (87Sr/86Sr)i = 0.7073-0.7068 these magma originated within the continental crust. The episode of Middle Eocene to Early Oligocene (39-30 Ma.) was very important in term of magmatism and mineralization. Diorite, monzonite, quartz monzonite, and granodiorite are reported in different part of the Lut Block. Based on mineralogy, high values of magnetic susceptibility [(400 to 1600) × 10-5 SI], and low initial 87Sr/86Sr < 0.7057, they are classified as belonging to the magnetite-series of oxidant I-type granitoids. These magmas originated above a subduction zone. Basaltic rocks within the Lut Block near Ferdows (42 Ma) and Mud (31.4 Ma) have signatures of island arc basalts. Younger Neogene basaltic rocks (15.5 to 1.74 Ma) from East Neh along the eastern margin of Lut Block and Nayband area along the western margin of Lut Block have the characteristic of ocean island basalts.

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