الملف ١٤٥٠\١٩١٩ "بلاد الرافدين وكردستان: تقارير جيولوجية عنها" [ظ‎‎٢‎١‎٠] (٥٢٢/٤٥١)

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boundary drawn along the upper part of the Haudh stream-course; this also-
fell info line with what appeared to be the same boundary line separating
Lower Ears and Red Clays on tlie opposite bank of the river near Duwaisat
Mansur. From Shura to Mosul none of the Red Clay and Sandstone series
was seen. _ T .. . . 1
Mesopotamian Alluvium .—The gravel above Haudh belongs to the
Mesopotamian Alluvium, which forms the usual plateau, and is argillaceous
in character. It is pebbly around Hammam Ali.
New Alluvium .—The New Alluvium is pebbly N. of Hammam Ali.
STRUCTURE.
The Mishrak anticlinal axis follows the sigmoidal curve of the highest
points of the range, extending from Safinah, N.W’wards to near Rassif,
curving N.N.W’wards past Jabaunam and swinging round past Kharrar to
a direction a little N. of west. The crest reaches its highest point near Tel
Sulaiman, S.E. of which it pitches, at first gently and finally with an abrupt
ness not much less than 20 degrees, beneath the alluvium at Hadra and
Safinah. There appeared to be an outcrop of Lower Ears, succeeded by Red
Clays and Sandstones to the S., on the opposite bank of the Tigris, shewing
that the fold persists across the river; the bed of the latter is here character
ised by rapids. N.N.W’wards from the crest-maximum there appears to be
a gentle pitch, but the N.E. limb of the anticline N. of Jabaunam becomes
involved in a vast rolling outcrop of Lower Ears stretching right up to Mosul
and far out to the west, with very gentle dips and numerous minor low undu
lations. It would be impossible to indicate these vagaries on a J-inch map,
even if it were more accurate than the one available, but the original
anticlinal axis is dimly persistent through the high ground immediately S.
of Kharrar, when there may possibly be a slight rise of the crest.
With regard to the flanks, contrary to the rule hitherto observed, and
perhaps as a result of the close proximity of a second anticline on the S.W.,
the N.E. limb of the fold is, in a general way, steeper than the S.W. I say
“ in a general way,” because there is considerable irregularity in the N.E.
limb and some undulation in the S.W. The map is on too small a scale to
indicate these variations, but there are some quite pronounced plunges and
recoveries on the part of the N.E. limb, and in more than one spot a subsi
diary anticlinical pucker. Where the anticline pitches and indeed through
out the whole structure the dip is never steady for any distance. Although
dips of 30 degrees and more occur in the N.E. limb, the general maximum
dip is probably nearer 15 degrees, while that on the S.W. is still less. The
parallel anticline whose axis appears to be about 2| miles S.W. of the
Mishrak axis is so low and flat as to be only just recognisable near Shura.
N. of Jabaunam there seems to be a small flat N’wardly pitching branch
fold. From Kharrar N.E’wards the dip is, with few and unimportant inter
ruptions, N.E. as far as the alluvial plain in which Hammam Ali occurs,
so. that the oil and sulphur indications of the latter locality may be connected
with the Mishrak fold, perhaps lying upon one of two ofl-shoots or branches
which seem to be indicated in the opposite river banks, and which may be
the result of the swinging round of the Mishrak axis. Examination of the
opposite bank is.necessary before deciding whether this is so, or whether
the Hammam Ali Oil exudations belong to a different anticlinal system on
that side of the river. For about six miles W\ of Hammam Ali this general
N.E ly or N.N.E ly dip persists, when a slight change commences, and
two miles further W. a district near W.N.W.—E.S.E. anticlinal arch can
be made out.
PETROLEUM AND SULPHUR.
Natural Indications. —One emanation of sulphuretted hydrogen was
observed near Rassif. From the top of the cliffs a sulphur occurrence of
importance was observed in a blocked branch ,of the Tigris immediately
above the entrance of the Greater Zab. This forms a vast pool of sulphur-
yellow v a ter, the odour of sulphuretted hydrogen fro m which can be per
ceived throughout the Misrak hills during an E’ly wind. Sulphur can
be seen issuing from two or three sources, accompanied in one place at least
by a.black substance which might be tar. The Arabs report that a poisonous
gas is evolved therefrom .which will overpower anyone unwary enough to
approach too closely. This report is probably true, as the gas is no doubt
concentrated sulphuretted hydrogen. I could elicit no confirmation of the
presence of bitumen or tar here, the locality having such a bad name as to
e seldom visited. As it seemed more than probable that oil indications
must exist somewhere in the hills, my interpreter was sent on a long round,
and atter. bemg shown two more sulphur localities, was at length successful
m obtammg information of a small seepage of tar, to which he was led by
an Arab who had. noticed it while out shooting, and of which he brought
ac \ samples; it lies on high ground in a stream-course a mile or so W. of
ie arge sulphur emanation in the river Tigris, and consists of a slow trickle-
o± tarry oil, producing a small quantity of asphalt.