| Zagros Active Fold –thrust Belt is situated in the northern margin of the Arabian Plat and
formed due to shortening, thickening and uplift of tethys sedimentary basin between Arabian
and Iranian plates. In this study, the rate of uplift in the northern margin of the Zagros
Mountains in southern Iran are examined. The Zagros fault zone in this region is composed of
a set faults, including Deragah, Haji Abad, Tezerj and several other faults and also we call
these branches from F1 to F8. These segments puts from northwest to the East- Southeast.
Based on field surveys and Geological maps, we prepared a structural map from
major faults of Zagros fault system for identify faults pattern and estimating of
uplift rate movements in Zagros fault. Three methods used to calculation of uplift
rate:
A: Asymmetry index
Accordance with the procedure, in studied area, northeast drainage are longer than of
southwest drainage and east minor drainages also longer than the west side drainages,
Uplifting in this region is characterized by mentioned asymmetry factor. The amount of this
index is AF=71.81.
B. Interaction between the faults movements and erosion process
We comparison contrast between uplifting movement rates and erosion rates
in different parts of studied region by Smf and other indexes. Average amount of
Smf=1.1.
C. Evaluation of Uplift rate of alluvial terraces was performed by sediment ages and
terraces height.
We surveyed Quaternary facieses which have ages between 17,000 and 30,000 years old.
the rate of uplifting for each fault is follows : Deragah fault and F8 fault between 1.0 to
1.85mm per year and F7, F6, F5, and F4 faults, have a rate Uplifting between 0.6 to 1.0
mm per year and the rate of Uplift for other faults is between 0.04 to 0.06 mm per
year.
According to our studies, uplift rates in north -east and south-west more than other
regions
The minimum rate at different stations are about 0.5mm/y to 0.93mm/y and its maximum
is 0.88 mm/y to 1.47mm/y. |