'IRAQ AND THE PERSIAN GULF' [‎50r] (104/862)

DESCRIPTION OF THE LAND 57
dotted about near the Persian boundary south of the latitude of Ali
Gharbi, are almost flush with the level of the alluvial plain.
The second chain is the north-west continuation of folds in the
neighbouring Persian foothills. One of these, half in Persia and half
in Iraq, contains the oilfield of Naft Khaneh, 30 miles east of Shah-
raban; it supplies petrol to both Baghdad and Kermanshah. Along
the same strike north of the Diyala there are two small domes between
the Jabal Hamrin and Kifri, and then a long gap where the alluvium
of the plain south of Kirkuk, east and west of the Little Zab, covers
everything for nearly 100 miles; whether there are buried folds
beneath the alluvium is not known, but the chain seems to be con
tinued by the Jabal Hibbara and Jabal Qaiyara, which emerge west
of the Tigris about 50 miles above Fat-ha. They are on almost the
same strike as Naft Khaneh, and one of them yielded oil as a result
of shallow drilling by the Germans during the War of 1914-1918.
Jabal Shaikh Ibrahim may be an extension.
The third chain is parallel to this Naft Khaneh line, where the 5°"
mile fold of Kifri (Jabal Shakal) runs north-west of the Diyala, and,
after a gap of the same length south of Kirkuk, appears again as the
conspicuous elongated dome of the Jabal Qara Chauq between the
Little Zab and the Tigris which cuts across its plunging end. A
small group of folds extends this structure to the west, Jabal Sasan
acting as a link with Jabal Sinjar. ... . ,
The fourth chain leaves Persia near Qasr-i-Shirin and is almost
continuous as far as the Tigris near Mosul. It is depressed at Chia-
Surkh, south-east of the Diyala—where some of the earliest drilling
for oil in Iraq was carried out with tantalizing results—but the Jabal
Tasak, for 50 miles north-west of the Diyala, and the low hills of
Kirkuk mark the line. These last have been drilled and form a
productive field, from which oil is now pumped through pipe-lines
to the Mediterranean. The surface structure is thrust-faulted, but
the limestone below, whence the oil is derived, forms a large gentle
unbroken arch. Beyond the Little Zab the Avana Dagh extends the
chain for another 30 miles. The last visible component is a low fold
just south of Mosul; the Jabal Atshan may be an extension.
The belt of country for nearly 20 miles beyond the fourth chain is
only gently warped; then folds again become numerous, though as
individual chains they are less easy to describe from end to end,
because they are closer together and the rivers have cut deeply into
them. Between the Diyala and the Little Zab there are three paralle
flexures forming the broad swelling at Chemchemal, the more con-