File 1450/1919 ‘Mesopotamia & Kurdistan: Geological Reports on’ [‎80v] (175/522)

8
The examination of the left bank of the Tigiris, which is in om wintei progtamme, should
throw much light on the occurrence of the springs.
Central ami. —Between the south end of the northern and the north end of the- southern axis
there exits two to three miles of country through which we were unable to trace any definite axis.
The Mishraq Limstone is not exposed over the area and the dominating limestone is Limestone D.,
which now caps nearly all the hills and originally formed a continuous outcrop over the whole of
this part of the country. Running into this central part from the Tigris we found evidence of two
synclinals with E.W., or E.N.E.-W.S.W. trend ; wadi A seasonal or intermittent watercourse, or the valley in which it flows. Jahannam runs in one of these and a wadi A seasonal or intermittent watercourse, or the valley in which it flows.
near the village of Munirah in the other. We believe that the capricious rolling of the country
here is due to the interference of these two synclines with the main axis of the fold.
It will be seen from the above that we are, in this area, unable to agree with Dr. Pascoe on
many points but it must be remembered that we had the advantage of the use of the new senes
survey maps, which were not available when he examined the region and that we spent considerable
time in correlating the limestone bands whereas he was much hindered by atrocious weather .
*
Prospects —
{a) Presence of oil-bearing beds.— The Lower Ears beds which must provisionally be considered
to be the oil bearing beds of the district, form the whole core of the anticlines. ^ The ai ^ a ^
surrounded by seepages (Hammam Ali to N.E., Nimrud to the E., Oaiyarah to the S.) and tmee
seepage areas occur in the hills themselves ; in the two new areas which we discovered a consider
able amount of oil seeps up. The small seepage mentioned by Dr. Pascoe we were unable to find.
( 6 ) Cap Rock.— The maximum depth to which the Lower Ears beds are exposed is 400 feet
whereas in the Qaiyarah dome the wells bored by the Germans have struck oil-bearing beds about
650 feet from the top of the series. At the crest maximum of the southern anticline thill 942) the
series is not exposed below the Mishraq Limestone ; that is not more than 280 feet are exposed.
There should therefore be sufficient cap rock to have retained the oil.
(c) Structure. —The southern anticline is regular with a flattish top, rising to a maximum at
hill 942 and with dips on the flanks increasing near the junction with the Upper Ears. Ihere is a
low pitch away from hill 942 both to N.N.W. and S.S.E.*
The structure may therefore be considered favourable for the accumulation of oil and we
consider the prospects good enough to warrant a test.
The northern axis appears to rise into flat upland, but both this area and the cential aiea-
Should be mapped in detail on a scale of 3" = 1 mile to discover if the subsidiary synchnes running
more or less at right angles to the fold, have created reservoirs between them suitable tor the
accumulation and retention of oil.
(7) EXPLANATION OE MAPS, DIAGRAMS, Etc.
The General Geological map on the scale of 4 miles to one inch has been made to give a
general idea of the structure of the country examined. The topography in the neighbourhood of
the Tigris is correct, but further west the hills, etc., are only approximately located as the 2 nich
and \ inch maps are inaccurate
Much detail has had to be omitted on this small scale map and only essential boundaries and
main structure is shown.
Sheet of Sections.
All except the general 4 inch section, are taken from the 1 inch maps, on which the work was
done. The l inch section is a broken line ; this was necessary to get a section which would show
all the anticlines.
The Vertical Sections of the Lower Ears Series.
Wherever possible we attempted to get the succession of the beds and their thickness and the
vertical sections are the result of traverses from the junction with the Upper Ears to the outcrop
of the lowest exposed beds. It is evident that it is difficult to estimate the thickness of beds on
the flank of an anticline where the dip is changng from perhaps 60 deg. to horizontal within the
space of a mile ; and although the actual succession of bed is correct, the thickness may be easily
under or overestimated. The vertical sections are given as actually noted in the field. Thus in
the correlation of fhe limestones In the Qaiyarah, Najmah and Mishraq-Araij areas Limestone
varies somewhat in its position relative to the top of the series ; as we aie satisfied that we veie
dealing with the same limestone in each case, it is probable that the irregularity is due to ei 101 s m
estimation of thicknesses.
SUMMARY.
The area covered by this Report lies pn the right bank of the Tigris between Baiji and Mosul
and includes some 2,000 square miles of country.
Geological Formations.
Only the Lower and Upper Ears Series are exposed.
Lower Ears.
In general the beds are the same as described in Report No. 1 on the Qaiyarah Anticline.
Two types of limestone occur, type “a” which is the ordinary fossiliferous brown limestone usua y
in bands of 1—4 feet thickness. Type “b” is a white crystalline porous limestone without
fossils and is found in beds up to 15 feet thick. Certain limestone bands have been named loi

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