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BERBERIAN AND KING 219
TABLE 2. Correlation chart of the major Mesozoic rock units, sedimentary gaps (blank areas), and unconformities (indented
lines) in Iran, Arabia, and the Little Caucasus (for which the lower part of the section is not complete). The pelagic sediments
the High-Zagros Alpine Ocean (H.Z.A.O.), Sanandaj-Sirjan belt (S-S), Central Iranian narrow oceans (C.I.O.), and
Sevan-Akera (S-A) of the Little Caucasus, are shown by the wavy lines. The arrows indicate the emplacement of the ophiolites
and pelagic sediments as thrust sheets (thick lines with triangles) onto the continental margin
Arabia Zagros H-Z H.Z.A.O. I ST,~q I C.I.O. IC~ntrcal I. Alborz Talesh S-A L.Cauca’s
same region occurred during Late Cretaceous time and is
presumably associated with the final stages of subduction.
During this period, north and west Iran were subject
to little activity, with slight erosion and little deposition
suggesting low relief. After the emplacement of ophiolites
onto the continental margin in Late Cretaceous time,
a major flysch basin formed in east (Zabol-Baluch),
southeast (Makran), and southwest Central Iran (along
the Zagros fault line), and very rapid erosion and deposition
of material took place. The nature of the basement
of these flysch basins could be oceanic crust. The general
environment would appear to be relatively subdued
topography near sea level, except near the flysch basins
where, at the very least, steep scarp slopes would be
needed to provide the rapid erosion to supply the basins
with sediment (Fig. 7). Continental accretion of the
overlying Tertiary flysch deposits by the successive
oceanward movements of the site of the active subduction
zone along southern Makran (Fig. 1) presumably
gave rise to the subduction complex, which has continued
from Late Cretaceous time to the present (Figs.
to 9).
Extensive volcanism, with a wide range of composition,
started in the Eocene Period (50 Ma) and continued
for the rest of the period with the climax in Middle
Eocene time (about 47-42 Ma). Despite their great
thickness (locally up to 6 and 12 km) and wide distribution
(Fig. 7), the volcanics and tufts were formed
within a relatively short time interval. Since the plutonic
eugeosyncline north of the Hercynian subduction zone. 9. Approximate boundary between different sedimentary facies. 10.
Spreading centres. 11. Subduction zone with triangles on the upper plate. 12. Major normal faults activated during the Permian
rifting phase, controlling the sedimentary facies. 13. Reverse faults with bars on the upper plate. 14. Present continental
shorelines. 15. Epigeosyncline orogenic region in the north. SS: Sanandaj-Sirjan rift belt. t.c.m.m.: Transcaucasian Median
Mass.
Principal sources of data: Reconstruction (Mercator Projection) is modified from Smithetal. (1973). The tectono-sedimentary
data within the Iranian boundaries are based on our Fig. 11. Data outside Iran come from Wolfart (1967), Nalvkin and Posner
(1968), Adamia (1968, 1975), Gass and Gibson (1969), Kamen-Kaye (1970), Brown (1972), Belov (1972), et al.
(1977), and Saint-Marc (1978).