الملف ١٤٥٠\١٩١٩ "بلاد الرافدين وكردستان: تقارير جيولوجية عنها" [و‎‎١‎٤] (٥٢٢/٣٢)

8
Lower Eocene.
A dark marl series with sandstone and occasional limestone beds. The thickness is very much
less than that of the Eocene Shale series found at Sulaimaniyah, being, here, not more than 1,000
feet. In places this thickness seems to be even more reduced, as at Botas where it was estimated at
about 300 feet.
We have the impression that the Eocene was laid down in troughs in the already folded,
though not necessarily exposed, Cretaceous strata, but we have not yet sufficient evidence to state
that there is a general thinning of these beds over the anticlinorum to be described below.
Upper Eocene.
Two distinct types of Upper Eocene are found in the area mapped. In Jabal Maglub and the
Oarah Chaugh Dagh beds of the same type as described from Sulaimaniyah are found (See—Geolo
gical Report No. 8), but in Jabal Maglub*the Nummulitic limestone is either absent or not exposed
and at the Qarah Chaugh Dagh we did not lind the Nummulites mentioned by Porro and Kissling,
though this horizon may be exposed in some section of the northern hill that we did not examine.
In these hills below the white limestone we found a yellowish thinly bedded tissile limestone, from
which we obtained two corals in iron pyrites, but no Nummulites.
The Upper Eocene of the Kurdish hills to the east and north-east of Arbil is of an entirely
different type, consisting of interbedded limestones, shales and a few sandstones. Usually there are
three well marked limestone horizons. A particularly thick bed occurs at the top of the series
(from 300-400 feet thick), and has below it about 100 feet of a very distinctive brilliant red marl,
followed by limestone, marls and sandstone. It was seen that in the Setin Dagh district the red
marl was separated from the limestone above it by a conglomerate 10-15 feet thick. This section
closely resembles the section described by Loftus from Mangenah in Persia. (See reference above).
Some of the limestone beds were crowded with crushed fossil remains, but Cardium and Ostrea
were the only recognisable forms collected.
Lower Ears.
Complete sections of this formation have been examined at Qarah Chaugh Dagh and Koi
Sanjak. The thinning from the Tigrish valley toward the east and north-east is well marked. The
vertical sections attached give the succession of the beds from Qaiyarah to Koi Sanjak.
In the Qarah Chaugh Dagh, where a good section is visible, the Lower Ears is of the same
type as Qaiyarah. Near the base (unexposed at Qaiyarah) there are two thick beds of extremely
cellular limestone, the lower one closely resembling the laminated lime stone of Fathah, which is
there oil soaked.
At Quwair the Lower Ears is of the same type, but only about 250 feet is exposed.
A Koi Sanjak, to the east of Arbil, the formation has thinned out to not more than 300-400 feet
and the beds of Gypsum disappear altogether north-east of the line of the Selin Dagh. The lime
stones in these beds gradually assume an Eocene facies as one travels to the north-east and a few
thin beds of limestone and marl which occur in the Babachichck valley and at Shaqlawa have been
referred to Eocene in the absence of gypsum, fossils or any break between the series.
No unconformity has been met with anywhere, but at Koi Sanjak there is a thin band of. lime
stone breccia at what is taken to be the base of the Lower Ears.
Upper Ears is present in one valley deep in the hills and has here no gypsiferous deposits,
below it. We therefore believe that the line of the Sefin Dagh was a boundary of the “ gypsum
sea”.
Upper Ears.
The beds in this area are of the Tigris valley type.
Bakhtiari Beds.
Of normal type. The conglomeratic phase is well developed over a large part of the area.
We found pebbles ,of Nummulitic Limestone in the conglomerates near Altun Kupri.
Recent Deposits
River gravels occur in the valleys of the Greater and Lesser Zab rivers. In the Arbil Plain
there is a considerable thickness of " wash ” from the Bakhtiari Beds, which has obscured all out
crops.
(4) INDICATIONS OF OIL, SULPHUR, ETC.
Seepages of oz7.—The only seepage of oil which occurs in this district is on the bank of the
Greater Zab river on the plunging end of the Quwair dome. A small amount of fluid oil seeps up
into pools through a recent gravel, which covers thinly the solid rock below. Fragments of oil
soaked limestone were found near the seepages ; this limestone is not cellular.
(a) Sulphur .—Large sulphur springs occur in the Lower Ears at small village about 1 mile
south-east of Makhmur in the Qarah Chaugh Dagh.
[b) A warm spiing smelling of sulphuretted Hydrogen gas occurs near Babachichck about
the crest of a small dome in the Lower Eocene.