The
Creation of Mountains
In as much as volcanoes abound at divergent boundaries under the seam, such
eruptive features are also abundant on land. Most of the current oceanic
volcanoes have been active for a period of 20-30 million years or even more
(e.g. the canary Islands). During such a long period of activity, older
volcanoes were gradually carried away from the rift zone by sea-floor spreading
until they became out of reach of the magma body that used to feed them and
hence faded out gradually and died. The floor of the present day Pacific Ocean
is studded with a large number of submerged, non-eruptive (dead) volcanic cones
(guyots) that are believed to have come into being by a similar process.
Continental
orogenic belts are the result of plate boundary interaction, which can take
place between oceanic and continental lithospheric plates that reaches its
climax when two continents come into collision after consuming the ocean floor
that used to separate them. Such continent/continent collisions result in the
scraping off of all sediments and sedimentary rocks, as well as all volcanic
rocks that have accumulated on the ocean floor, squeezing them between the two
colliding continents, crumpling them considerably in the form of mountains. This
is immediately followed by the cessation of movement for the two colliding
continental plates which become welded together with considerable crustal
shortening (in the form of giant thrusts and infrastructural napes) and
considerable crustal thickening (in the form of the decoupling of the two
lithospheric plates as well as their penetration by the deep downward extensions
of the mountain chains then formed). Such downward extensions of the mountains
are commonly known as "mountain roots" and are several times their
protrusion above the ground surface. The sea-deep roots stabilize the
continental masses (or plates), as plate motions are almost completely halted by
their formation, especially when the mountain mass is finally entrapped within a
continent as an old craton.
Again,
the notion of a plastic layer (asthenosphere) directly below the outer rocky
cover of the Earth (lithosphere) makes it possible to understand why the
continents are elevated above the oceanic basins, why the crust beneath them is
much thicker (30-40) km) than it is beneath the oceans (5-8 km) and why the
thickness of the continental plates (100-150 km) is much greater than that of
the oceanic plates (65 70 km). This is simply because of the fact that the less
dense lithosphere (about 2.7 to 2.9 gm/cm³) floats in the asthenosphere, in
exactly the same way as an iceberg floats in the oceanic waters.
In
as much as mountains have very deep roots, all other elevated regions such as
plateaus and continents must have corresponding (although much shallower) roots,
extending downward into the asthenosphere. In other words, the entire
lithosphere is floating above the plastic or semi-plastic asthenosphere, and its
elevated structures are held steadily by their downwardly plunging roots
(test-fig. 10).
Lithospheric plates move about along the surface of the Earth in response to the
way in which heat flows arrive at the base of the lithosphere (text-fig. 11),
aided by both the rotation and the wobbling of the Earth around its own axis.
There is enough geologic evidence to support the fact that both processes have
been much more active in the distant geologic past, slowing gradually with time.
Consequently, it is believed that plate movements operated much more rapidly in
the early stages of the creation of the Earth and have been steadily slowing
down with the steady building-up of mountains and the accretion of continents.
This slowing down of plate movements may also have been aided by a steady
slowing down in the speed of the Earth's rotation around its own axis (due to
the operating influence of tides which is attributed to the gravitational pull
of both the sun and the moon). This steady slowing down of plate movement could
also have been aided by a steady decrease in the amount of heat arriving from
the interior of the Earth towards its surface as a result of the continued
consumption of the source of such heat flows which is believed to be the decay
of radioactive elements.
Earth’s
Stability in the Quran
The
above-mentioned discussion clearly indicates that one of the basic functions of
the mountains on land is its role in stabilizing continental masses lest these
would shake and jerk, making life virtually impossible on the surface of our
planet. This fact is stressed in ten Quranic verses as follows:
[XIII:
3; XV: 19; XVI: 15; XXI: 15; XXI: 31; XXVII: 61; XXXI: 10; XLI: 10; L: 7; LXXVII:
25-27; and LXXIX: 32-33].
These
verses also indicate that the outer rocky cover of the earth has been spreading
out and accreting since the early phases of creation of the earth through
intensive volcanic activity.
Via
such activity both the atmosphere and the hydrosphere of the earth have been
outgassed, its lithosphere has been built and rifted into separate plates, its
lithospheric plates have been set in movement and stabilized as well as the
whole planet.
The
stabilization of lithospheric plates by mountains is effected by their sinking
deeply into the zone of weakness of the Earth (the asthenosphere) as wooden pegs
sink into the ground to stabilize the corners of a tent. Such a process of
stabilization cannot take place without the presence of a viscous, plastic
material under the outer rocky cover of the Earth, into which the mountains
"roots" can float. In as much as the ship casts its anchor into
the anchorage of a port to avoid the dangers of rolling and swaying by winds and
waves, the Glorious Quran uses the term "Rawasi" (=moorings or firm
anchors) to describe mountains. Such firm anchors do not only stabilize the
lithospheric plates, but also the whole planet in its spinning around its own
axis (nutation, recession, etc.).
The
precedence of the Holy Quran with more than 14 centuries in describing these
phenomena is a clear testimony of the fact that this Noble Book is the word of
The Creator in its divine purity and the Prophet Mohammed (PBUH) is His final
messenger. In an authentic saying, this noble Prophet is quoted to have said
that: "When Allah created the Earth it started to shake and jerk, then
Allah stabilized it by the mountains.” This unlettered Prophet lived at a time
(between 570 and 632 C. E.) when no other man was aware of such facts, which
only started to unfold by the beginning of the twentieth century and was not
finally formulated until towards its very end.
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