crater of this volcano opens towards the north, and has a depth of 108
feet below the edge, with moderately steep sloping sides (17 deg.-32 deg.),
while the slope of the exterior, at first steep, gradually lessens to
20 deg.-21 deg.. These slopes are covered with reddish or yellowish slag. The
above examples will probably suffice to afford the reader a general idea
of the size and form of the volcanoes in this little known region.
It has been stated above that the great lava-floods have probably been
poured forth intermittently. The statement receives confirmation from
the observations of Canon Tristram, made in the valley of the Yarmuk.[8]
This impetuous torrent rushes down a gorge, sometimes having limestone
on one side and a wall of basalt on the other. This is due to the fact
that the river channel had been eroded before the volcanic eruptions had
commenced; but on the lava-stream reaching the channel, it naturally
descended towards the valley of the Jordan along its bed, displacing the
river, or converting it into clouds of steam. Subsequently the river
again hewed out its channel, sometimes in the lava, sometimes between
this rock and the chalky limestone. But, in addition to this, it has
been observed that there is a bed of river gravel interposed between two
sheets of basalt in the Yarmuk ravine; showing that after the first flow
of that molten rock the river reoccupied its channel, which was
afterwards invaded by another molten lava-stream, into which the waters
have again furrowed the channel which they now occupy. The basaltic
sheets descend under the waters of the Sea of Galilee on the east side,
and were probably connected with those of Safed, crossing the Jordan
valley north of that lake; owing to this the waters of the Lake of Merom
(Huleh) were pent up, and formerly covered an extensive tract, now
formed of alluvial deposits.
(_d._) _Land of Moab._--Proceeding southwards into the Land of Moab, the
volcanic phenomena are here of great interest. Extensive sheets of
basaltic lava, described as far back as 1807 by Seetzen, and more
recently by Lartet and Tristram, are found at intervals between the
Wadies Mojib (Arnon) and Haidan. On either side of the Mojib, cliffs of
columnar basalt are seen capping the beds of white Cretaceous limestone,
while a large mass has descended into the W. Haidan between cliffs of
limestone and marl on either hand.
Around Jebel Attarus--a dome-shaped hill of limestone--a she
|