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BERBERIAN AND KING 227
NEOGENE
/ I
-’-’-’-10, --’--’-- 11 , ""-"12," ........ 13
FIG. 9. Reconstruction of Iran during Middle-Late Neogene time (about 10-4 Ma). Shortening and thickening of the
continental crust has narrowed the intermontane continental basins. Most of Iran was above sea level and the mountain systems
were extensive features. The gradual uplift of the Zagros basin from northeast to southwest is noticeable (cf. Fig. 17 for the
detailed Iranian tectono-sedimentary data). Subduction of the oceanic crust of the Arabian plate beneath the Makran coast was
presumably responsible for the calc-alkaline andesitic volcanism in northern Makran. Seaward accretion and landward
underthrusting of flysch deposits possibly elevated the Makran range of southeast Iran.
1. Oceanic crust area. 2. Continental areas of erosion and non-marine sedimentation. 3. Terrestrial red clastic rocks in Zagros
(Agha Jari Formation), and gypsiferous saliferous red continental deposits in Central and northern Iran. 4. Marine molasse
coastal Makran, southeastern Iran. 5. Marine sediments of Caspian, northern Iran. 6. Intrusive rocks. 7. Volcanic rocks.
8. Approximate boundary between different sedimentary facies, or mountain-basin boundary. 9. Spreading centre in the Red
Sea. 10. Subduction zone, with triangles on the upper plate in Makran, southeastern Iran. 11. Reverse faults, with bars on the
upper plate. 12. Rifting in the Afar region. 13. Present continental shorelines.
Principal sources of data: Reconstruction (Mercator Conformal Projection) is modified from Smith and Briden (1977).
tectono-sedimentary data within the boundaries of Iran are based on our Fig. 17. Data outside Iran come from Biju-Duval et al.
(1977) for the westernmost part.