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الثلاثاء، 21 مايو، 2013

“And He has affixed into the earth mountains standing firm,-2-

الثلاثاء, مايو 21, 2013

There are two theories to explain the origin of mountains in the earth.

  1. The Geosynclines Theory:

There were large depositional basins from seas and oceans ranging from hundreds of kilometers in length, tens of kilometers in width to more than one hundred meters depth. Many clastic and non-clastic types of sediments were deposited and accumulated in the floors of theses basins, in the form of throwing from up to down to form sedimentary rocks. The continuous thickening of these rocks caused loads and led to subsidence of the basin floor. This subsidence was accompanied by volcanic activity in the form of eruptions throwing the lava upwardly.  The result was a thick intercalated sequence (about 1500m thick) form sedimentary and volcanic rocks. However, the depositional basins are bounded by active deep rifting faults which keep the continuous subsidence of the basins and two opposite wards the processes of deposition downwardly and the eruption of lava upwardly.

  1. Plate Tectonic Theory: This recent theory depends on some facts in explaining the origin of mountains as follow:

  1. The earth’s crust is broken up into plates or partitions called “tectonic plates” through cracks that can range from 65 to 150 kilometers in depth. The plate that forms the ocean floor is called ‘oceanic plate’ and that which forms the continent is called ‘continental plate’. Around the earth there are about 12 large plates and several small ones. These plates which formed from continental or oceanic crust float on hot, semi-molten materials of weak sphere (Asthenosphere). There is continuous movement between the adjacent plates, which is extensional,compressional or transformable (sliding), occurs along a relatively narrow zone where plate tectonic forces are most active. Usually, these movements are accompanied by volcanic and seismic activities (earthquakes). The volcanoes erupt and throw lava and magma to the surface until the magma gathers and crystallize as volcanic rocks creating a mountain which can reach heights of up to thousands of meters above sea level. This is because volcano activity can last for 20- 30 years (although some volcanoes have been recorded as staying active for more than a thousand million years).

Examples of volcanic mountains include: Mount Ararat in Turkey (5100m), Mount Etna in SicilyItaly (3300m), Mount Vesuvius in Italy (1300m), Kilimanjaro inTanzania (5900m) and Mount Kenya in Kenya (5100m).

  1. Throughout the field studies it was noted that; orogenic belts consist of rocks that have been folded intensively, thrust long distances horizontally, often metamorphosed, intruded with granite and elevated to form mountain chains. These belts result from the forces of compression and convergent movements of the plates, which makes up the solid outer part of the Earth’s crust. These forces usually rise at the margins of discrete rigid plates and are accounted for by the theory of plate tectonics. Two main types of plate are found as mentioned before: continental plates that consist of relatively light rocks and heavier oceanic plates, which lie under most of the ocean basins of the world. Compression occurs when two plates converge and one sinks below the other along a subduction zone. Convergence, and the subsequent collision that generates compression, takes in three forms: collision between oceanic plate with continental one, two continental plates or between two oceanic plates.

The first of these forms develops when convergence occurs along active continental margins where an oceanic plate is passing under the edge of a continental plate. As the oceanic plate descends into the mantle of the earth, it is melted and injected back into the crust, with volcanic activity to form mountain chain consists mainly of volcanic rocks. The second form of collision takes place between two oceanic plates leading to the subsidence of one of them and forming a series of islands in the form of ‘volcanic island arc’ in another oceanic plate. If this process continues, the volcanic island arc can be carried on the oceanic plate towards the continent where it collides with the continental plate—this is called an arc-continent collision. Sedimentary rocks which have accumulated in the sea basin between the island arc and the continental plate are folded, faulted, and thrust into an elevated position over the margin of the continental plate towards the centre of the continent along a plane or surface known as a decollement. The island arc eventually becomes involved in this compression and the rocks of which it was composed are often metamorphosed by heat and pressure and injected with granite.

The third form of compression and orogeny results from continent-continent collision (two continental plates). Typically in this type of collision, two continents converge, one with a passive margin in which the continental and oceanic crust are welded together, the other with an active margin where the subduction of the oceanic crust under the continent eventually causes the closure of the intervening ocean basin. As closure begins, slices of the oceanic crust and any sediment that they carry are thrust on to the continental margins. As the thrust continues the slices are folded and elevated and eventually move horizontally, possibly sliding due to gravity on to the continents to form huge folds or thrust-nappes. These nappes become eroded to form the mountain chains. As compression continues in the closing gap, high pressures and temperatures generate a linear zone in which the rocks are metamorphosed, eventually welding the continents together along a continental suture.
Forces associated with extension (spreading) or stretching in the Earth’s crust alsoproduce mountain ranges. Such forces occur where two plates are diverging or moving apart. At the early stages of development this divergence can lead to continental rupture where arching upwards and splitting of the crust occurs. Along the line of divergence a rift valley develops with the crack in the centre being continually filled with rising magma.Blocks on either side fall or slide down the side of the rift creating a mountainous landscape.

 

Description of the mountains as having deep roots and acting as anchorages:

 The modern theory of plate tectonics holds that mountains act as anchorages for the earth’s crust.  The crust is broken up into several tectonic plates through cracks that range from 65 to 150 kilometers in depth; there are about 12 large plates and several small ones. These plates, which contain the world’s continents and oceans, float on hot, semi-molten material, drifting and bumping against one another. Movement between the plates occurs along a relatively narrow zone where plate tectonic forces are most active i.e. in a weak zone of the earth’s crust. Thus the movement of those plates floating on molten magma coupled with the Earth’s movement around itself amount to a lot of force.

In addition, as the ocean basin grows as the sea floor spreads, the magma injected at the line of divergence creates a new mountain range called a mid-oceanic ridge. Thus, the only factor that limits the ferocity of the movement of the plates are the mountains that act as definite stabilizers for the earth’s crust, safeguarding the continents and oceans from constantly running into each other and not only does it decrease their velocity, it also regulates their movement!

Modern earth sciences have proven that mountains have deep roots under the surface of the ground and that these roots are several times their elevation above the surface of the Earth. We can thus safely conclude that the Qur’an’s description is accurate; the mountains are actually pegs in the earth’s weakest zones to anchor it firmly in the same way that we use anchors to firmly pin ships to the ground.


 A river is a flow of water along a channel from highlands to lowlands. The great majority of rivers eventually discharge either into seas or lakes, although some rivers disappear due to water loss through seepage into the ground and evaporation into the air.

The importance of rivers dwarfs their volumetric size (0.006 percent of all the fresh water of the earth). This is because river water flows down with gravity, giving it the power to mould the landscape through erosion, transportation and the deposition of rocks and sediments, making it a dynamic and renewable natural resource for human, plant, and animal life. The water cycle begins when water evaporates from the oceans into the atmosphere. Atmospheric water returns to Earth as precipitation in the form of rain, hail or snow. The amount of water reaching the ground depends on many factors but in general, highlands receive more precipitation than lowlands and most rivers originate in mountains. When precipitation reaches the ground, it usually seeps into the soil, either percolating down to the water-table to become groundwater, or flowing slowly downhill as through-flow. However, during heavy storms, due to human activity compacting the soil surface or covering it with concrete, or if the soil is already saturated, not all the water is able to infiltrate and the excess collects on the surface before flowing downhill to the nearest stream as overland flow. Water that reaches the river either by through-flow or overland flow is termed run-off. The role of the river in the water cycle is to complete the cycle by collecting run-off from the surrounding area (drainage basin) and carrying it back to the ocean or a lake in order to replace water that has evaporated.  At this point, we can guess the obvious connection between rivers and mountains explained to us in the Qur’an long ago.

However, with the ever changing climate, rivers can eventually dry out leaving their channels as pathways and roads for humans and animals alike to use; this is the association the Qur’an points out between rivers and roads. Rivers are the best means that Allah created for pathways in otherwise inaccessible locations such as mountains, hills and plateaus.

Conclusion

These facts were unknown to man for a long time. He started to gather information about nature and its mysteries slowly, but it was only in the mid-nineteenth century that these explanations started to make some sense and the bigger picture did not come into view until the mid 1960s.

The precise mention of such facts, is an assertion that the Noble Qur’an cannot be man-made and bears witness to the Prophethood and the message of the seal of the Prophet (SAWS) who received it. It proves how the Prophet was connected to the revelation and taught by the Creator. This come in assertion to the words of Allah that can be translated as, “And those to whom knowledge has come see that the (Revelation) sent down to thee from thy Lord, is the Truth, and that it guides to the Path of the Exalted (in Might), Worthy of all praise.” (Surat Saba' (Sheba): 6).

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