File 1450/1919 ‘Mesopotamia & Kurdistan: Geological Reports on’ [‎125r] (264/522)

Geological Report (Mesopotamia) No. 4
R ON THE cou NTRY ON THE RIGHT
BANK OF THE RIVER TIGRIS BETWEEN BAIJI AND MOSUL.
INTRODUCTION.
The country covered by this report lies on the right bank of the River Tigris between Baiji
and Mosul Small portions ol the country on the left bank have been examined, where it was
necessary to tol ow structure. The area examined was about 2,000 square miles. Geological
Repot No. 1, on the Qaiyaiah anticline falls within this area and should be referred to.
(1) MAPS.
Most of the aiea has been suiveyed on the scale of 1 // = 1 mile and this much facilitated our
woik as the maps^ are excellent for quick reconnaissance work. Outside the boundaries of these
maps thete aie 7 and 1 scale, but these are tor the most pa^t very inaccurate. The maps
used are :—
New Series l": 138 M2/6, 138 M 1&5, 137 P/ 8 , 137 P/4, Mosul, T.C. Maps 227 A, 248.
i" maps, T.C. 171, 250, 172, 225.
i" maps, T.C. 147, 257. ,
(2) PREVIOUS WORK DONE IN THE DISTRICT.
In 1905 Porro and Kissling made a geological examination of the country and this included
a tour down the Tigris from Mosul. The seepages of Qaiyarah and Hammam Ali are described
and sections through the Jabal Hamrin and Jabal Khanuqah are given. We have had the oppor- I.
tunity of going over much of the country on which they reported and find that very little reliance ij
can be put on their interpretation of the structure. u
In 1910 Paul Grosskopf made a report for the Turkish civil list. He deals chiefly with the
possibilities of exploitation in the country. Dr. Pascoe made a geological examination in the
winter of 1918 and his reports have been of very great assistance in our work.
(3) GEOLOGICAL FORMATIONS.
The only solid formations found in the district are the Upper Ears and Lower Ears Series ;
in no place are the older beds exposed. Gravels of various ages and alluvium occupy a
considerable area near the Tigris. Alluvium has been mapped on the map.
Lower Ears.
/
This formation has been described in some detail in the Report on Qaiyarah and throughout
the large area examined it maintains its character in general, but there is a certain amount of
variation in the proportion* of the component beds—principally in the amount of Gypsum. As in
the Qaiyarah anticline gypsum is the chief constituent in the formation and the balance is marl
and lime stone. Sections have been prepared shewing the composition of the series in the several
anticlines. An attempt at correlation in the Qaiyarah, Najmah and Mishraq areas has been made,
but it has been found impossible to correlate particular beds in the Jabal Hamrin with those of the
anticlines to the north.
There are two types of limestone and we shall refer to them as type “ a ” and type “b’h
Type “ a ” is the ordinary fossiliferous limestone of brownish colour, usually rather flaggy and
containing some arenaceous material. It occurs mostly in bands from 1-4 feet thick and in parts
it is extraordinary fossiliferous and contains Ostrea, Pecten and Gasteropods and many other-
organic remains. Type “b” is a massive white crystalline limestone, unfossiliferous or with only
traces of fossil structure. It appears to contain a large proportion of arragonite and has the
appearance of having suffered recrystallization. It is very porous and in places has cavities up to
2 inches in diameter. An interesting fact is that limestones of type “b” do not make a feature
when they dip under other beds on the flank of an anticline as is usual with limestones of
type “a”. On large outcrops they become very shattered and appear to have poor powers of
resistance to denudation.
For the purposes of correlation we have found it necessary to give names to certain promi
nent limestone beds. In Report No. 1 on Qaiyarah the limestones were lettered and Limestone D.
has been traced into other anticlines. We have given the name Mishraq Limestone to la thick bed
ot type “ b ’ 1 which crops out over a large area in the north and comes 280 feet from the top of the
series. Below it is an easily recognisable group of limestone bands of type “a” at a depth of about
350—400 feet from the top and to which we have given the name of Araij Group of Limestone
In the southern anticlines, J. Makhul and Khanuqah the amount of limestone varies consider
ably in different parts of the hills, 3 s will be seen in the vertical sections, but on the whole the

File 1450/1919 ‘Mesopotamia & Kurdistan: Geological Reports on’ [‎125r] (264/522)

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