‘1 Diagrammatic Section N. of the Tuz Khurmatu’ [‎183r] (1/2)

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Zone u c ” consists of very light brown clay with very few sandstone bands. The latter
increase towards the base as the zone passes down into“b”. The sandstones usually contain
strings of pebbles, and thin inconstant conglomerates are seen in them and separating the clays.
This zone forms a comparatively low belt between the sandstone ridges of b” and the round
featured range of zone “ d.” Where the dip is low, open gently sloped country is produced,
but where the dip is steep, as on the Aq Su, there results a bewildering assemblage of steep
conical hills, which are almost as difficult to traverse as the sandstone ridges of b.” The
colour of the clay—an extremely pale brown—is very characteristic and differs from the red
of the zone “ a ” clays.
Zone “d” is typified especially by a thick somewhat loose conglomerate, which caps
a i on g, regular, level, uninterrupted range of hills, low or high according to the thickness
of the conglomerate, its dip and other factors. The conglomerate usually contains sandy
partings, and overlies light brown clay over which it has spilled its pebbles, producing
intricately dissected topography of which all the details are so rounded off and deprived of
sharp angles, that the zone can usually be identified from a long distance. Streams of good
water originate from it and the slopes of the range are typically more grassy than others. Other
conglomerates occur in the zone, sandstone is poorly represented, and light brown clay predominates
in actual bulk.
Zone “e.” Above the conglomerate forming the range just described, come thick masses
of light brown clay with a few thin conglomerates and sandstones. This zone is indistinguishable
from zone “ c ” except by its position. It forms slightly undulating plains.
Pleistocene.— On the S.E. side of the Kifri gorge is a horizontal conglomerate lying
uncomfortably upon the contorted Pars rocks, well up above the alluvial plain. It has been classed
as pleistocene and is probably equivalent to that seen at Fathah.
STRUCTURE.
As it is desirable that anyone anxious to prospect this area for oil, should form his own
conclusions as precisely as the evidence admits, as to the risks he has to face in searching for
undisturbed oil-pools below, the structure of the anticline will be discussed section by section from
N.W. to S.E.
The Ears beds first make their appearance from beneath the alluviums N. of Albu Sabah ;
they are here of very small thickness and practically vertical, so that the fold is steep and tight from
the commencement. Due E. of Albu Sabah the anticline is seen to use towards the in^ two
or three rapid jerks. Traced in the same direction the general N.E’ly dip sinks to 45,30 and
20° in places, being steeper along the N.E. than along the S.W. Pars boundary. This, we shall
see, is a very constant character all the way along the outcrop, viz., steep or steeply reversed dips
along the N.E. boundary, and gentle still more reversed dips along the S.W. boundary—reversed
in the opposite direction of course from those in the N.E. limb. In other words both limbs of the
anticline tend to become or do become, reversed, the S.W. limb much more than the N.E. N. of
Tuz Khurmatu, sandstones belonging to zone “ b” of the Red Clay and Sandstone Seties aie seen in
contact with the Pars along its S.W. boundary, dipping at about 20 in a N.E. direction ; this
boundary is, therefore, a reversed fault. Evidence of this fold-fault is again seen W. of kiin
where the conglomeratic zone d” is found within a mile of the Pars outciop, dipping gentU.
N. of Tuz Khurmatu the fold seems to be something of this nature :
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Traces of arches or crests can be made out along the S.W. face of the hills in one or two
spots, but there is much contortion.
Figs. 2 and 3 will give somes idea of the shape of the fold in the neighbourhood of the oil wells
at Palkanah opposite Suleiman Beg.
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