"تقرير عسكري عن جنوب غرب بلاد فارس، يتضمن أقاليم خوزستان (عربستان)، لورستان، وجزءًا من فارس" [‎٣‎٤‎٥] (٤٦٦/٣٩٢)

845
44
II
collection, made by the late Captain Newbold, E.I.C.S., from the beach of
Bushire (identified specimens are marked with an asterisk);
Fossil shells fromMuhammerah,
Neritka crepidularia,
JLamk,
Purpura.
Venus. entina crepiduiaria, Purpura (Rapana).
Area. ^ Lamk. Cerithium.
Melanopsis. Purpura. Cyprsea,
An examin ation of tlie fossils of this marine deposit [the Jezireh, or land
^ veen the rivers Tigris and Euphrates) proves that at a comparatively
recent period the littoral margin of the Persian Gulf extended certainly 250
miles further to the north-west than the present embouchure of the Shatt-al-
Arab, the combined stream of the Tigris and Euphrates^ and 150 miles
beyond the junction of these two great rivers at Korna.
The actual extent of this marine deposit to the north-west it is impossible
to define, as, from the nature of its formation in the shallow estuary, it
probably passes upwards gradually into the more recent fiuviatile beds.
Mr. Ainsworth, in his c Researches/ and Colonel Rawlinson in a paper read
before the Geographical Society in 1850, have both shown the rapid accumula
tion of this alluvial deposit, which is represented to increase a mile in thirty
years at the head of the Persian Gulf. It is therefore needless here to repeat
the investigation, especially as I have no new matter to add upon the subject.
3. Limestone gravel, —In many localities (especially in the neighbour
hood of Dizfdl, see fig. 8) on the outskirts of the great chain, an enormous
accumulation of gravel reposes nearly horizontally on the upturned edges
of the tertiary strata, or dips at a slight angle towards the plains on the
south-west, in which direction it gradually thins out. Seen from the plains at
sunset, these gravel masses present a very peculiar appearance, their surfaces
being cut up and deeply furrowed by innumerable channels, caused by the
heavy periodical rains. Towards the north-east and east, at their greatest ele
vation, they frequently terminate abruptly in a perpendicular escarpment. A
very remarkable instance of this occurs about twelve miles north-east of Dizful,
where, after attaining the summit of the range, the road is carried to the valley
of Gilalahu by a zigzag path down the face of a cliff, which, judging by the
eye, must be *200 feet in height, and is entirely composed of this limestone
gravel (see also fig. 2). The escarpment bears 12° S. of E. for a distance
of about 20 miles, being only interrupted by the passage of the
Diz and the Kunak stream. Magnificent sections are
course of these streams, as well as at the debouchure of the river Karkhah
into the plains of Arabistan. Masses of this deposit frequently stand isolated
from the main range, and, being precipitous on all sides, were formerly the
strongholds of the mountain chiefs. Tangawan, at the north-west extremity of
the escarpment above alluded to, is a conspicuous and fine example of an
isolated gravel fortress.
The town of Dizful is situated on the left bank of the river Diz, which
here cuts through cliffs of this gravel 60 feet high. The actual thickness of
the deposit is certainly not less than 100 feet in this locality (see fig. 3).
The serdabs, or cellars, in which the natives pass the day during the
scorching heat of summer, are excavated in it, and are reached by long flights
of steps.
Subterraneous canals called kanats, for irrigation derived from the river,
have been cut by Persian perseverance for miles through the gravel at a great
depth below the surface. Their course is traceable by the heaps of pebbles
river
obtained along the
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