'IRAQ AND THE PERSIAN GULF' [‎78v] (161/862)

IOO
GEOLOGY AND DESCRIPTION OF THE LAND
(b) The Mountain Basin of the Little Zab in Iraq (fig. 26)
This region is bounded by the Great Zab watershed on the west and
north, by the Persian boundary on the east, by the Diyala watershed
on the south, and by the Hab-es-Sultan Dagh and Tabin watersheds
on the south-west. Before entering Iraq the Little Zab drains a broad
upland valley some 60 miles long, with fine summer pastures grazed
by the Mangur and other tribes, and it is joined by the Baneh tribu
tary, which also has a fairly large basin among the high mountains of
western Persia. The international boundary is formed by the Baneh
river for about 6 miles above the junction and the Little Zab for 12
miles below. The frontier mountains are covered by the nappe of
Persian rocks almost to the point where the Qala Chulan enters the
Little Zab from the south, and both the Baneh with its tributary
the Nirvan, and the Shalar, Qizilja, and Gogasur—long affluents
of the Qala Chulan—drain valleys contrary to the strike of the folded
rocks farther west. The south-east to north-west pattern, which is so
marked in the Sulaimaniya and Bazian districts, is, however, con
tinued right through the basin of the Little Zab, the river itself
following the strike from the confluence of the Qala Chulan for 28
miles until it breaks through the Kuh-i-Resh at Darband-i-Ramakhan
and broadens its bed southwards across the Rania plain. Fifteen
miles farther south the hills again close in, and the Zab forces a wind
ing passage between the Hab-es-Sultan Dagh and the Pir-i-Mukurun
Dagh to enter the zone of the Assyrian foothills (p. 89).
The Hab-es-Sultan Dagh and the Kuh-i-Resh form the two chief
barriers. Between them on the right bank the Rubar-i-Basalam
collects the drainage of a number of valleys between parallel folds to
the north-west which continue across the watershed into the basin of
the Great Zab. On the left bank of the Little Zab, opposite the Rania
plain, open ground is less extensive, and the troughs are generally
drained by smaller independent tributaries, while in the south the
Tabin has captured two of them.
In describing the basin of the Diyala, four parallel ranges—the
Bazian, the Baranand, the Pir-i-Mukurun, and the Girjeh or Azmar
Dagh—were mentioned (p. 98). The first of these rapidly loses
height as it approaches the Little Zab and becomes one of the dis
continuous foothills of the Assyrian region (p. 89), though it can be
traced almost as far as Erbil. The Baranand Dagh and Pir-i-Mukurun
close in towards the Little Zab and to the north-west form the double
ridge of Hab-es-Sultan Dagh. The Azmar Dagh and new folds which