Fault Lines

June 30, 2011 by · Leave a Comment 

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Normal faults generally occur in places where the lithosphere is being stretched. Consequently they are the chief structural components of many sedimentary rift basins (e.g. the North Sea) where they have major significance for hydrocarbon exploration. They can also be found in deltas, at the rear edges of huge gravitation slumps and slides. Normal faults can show different geometries – and a few are shown here. In some situations the faults can become gently dipping at depth so that they have a spoon (or listric) shape. Other normal faults are found in batches, dipping in the same direction, with rotated fault blocks between. These are termed domino faults. Although most active normal faults can be shown to dip at angles steeper than 50 degrees, there are examples of very low-angle normal faults. These are often termed “detachments” – although this is a pretty vague term! Detachments show gentle dips and often expose high grade metamorphic rocks in their footwalls. These footwalls can be termed metamorphic core complexes. Normal faulting is now thought to be an important way in which metamorphic rocks come to be at the earth’s surface today.

Thrusts are reverse faults and commonly dominate the structure of collision mountain belts. Some thrusts have moved a long way – many mountain belts have thrusts that have moved many tens of kilometers. The photograph above shows one such structure from the Alps – which carries basement of the Mont Blanc massif onto Jurassic sediments. Many thrusts can be shown to follow so-called staircase trajectories. Otherwise, explore the nature of thrust systems by selecting from the icons. The material introduces concepts used in the Leeds first year structure course but some aspects are suited to higher level studies.

Strike-slip faults include some of the world’s most famous – or infamous structures, including the San Andreas Fault system and the North Anatolian Fault system. Both of these are renowned for devastating earthquakes. Strike-slip faults are those where the relative displacement is parallel to the strike of the fault. Strike-slip fault zones are commonly, but by no means exclusively, steep and can be rather difficult to recognize on cross-sections. 

All structures form in response to forces acting on rocks – and these give rise to stresses. In almost all geological situations stresses are always compressive but vary in different directions. We can evaluate the stress state in terms of the orientation and magnitudes of the so-called three principal stresses – which each act at 90 degrees to each other (i.e. they are orthogonal). Conventionally these are denoted using the Greek letter “sigma”. Patterns of conjugate faults – provided they formed together – can be related to the orientations of the principal stress axes.

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Martin Luther Kings’ Mountain Top

January 28, 2010 by · Leave a Comment 

By Imam Abdullah El-Amin, MMNS

Every year in the month of January I am reminded of the powerful persona and legacy of Dr. Martin Luther King Jr.  He was such a deep and prolific speaker that the gist of his speeches is still being felt today.  The “I Have a Dream” speech with its powerful message of hope, is so imbedded in our minds that for many of us, it the only speech we remember that he made.  Those of us who have faith and belief in ALLAH are constantly amazed at His revelations of His works.

On the eve of the assassination of Dr. King, he made a speech at a Baptist church in Memphis, Tennessee that many people believe foretold his eminent death.  He talked a lot about death that night.  He started with the story of the plane that bought him to Memphis and how the pilot delayed the flight because Dr. King was on it so it could be checked for bombs.

He also talked about a brush with death he had in New York when a crazed woman stabbed him with some sort of ice pick.  That assault brought the woman’s weapon dangerously close to Dr. King’s aorta (main blood vessel).  The doctor at the hospital told him the knife was so close that if Dr. King had sneezed he would have died because the pick would have pricked his aorta and he would have drowned in his own blood.  He used this incident to tell about a little white girl that wrote to him expressing her sorrow at his unfortunate incident.  She said she admired him so much and was so happy that he didn’t sneeze.   

Then he said he wasn’t afraid of death now because he had been to the mountain top.  He said God had allowed him to go up to the mountain top and he looked over, and saw the “Promised Land.”  He said he might not get there with us be he wanted us to know that we as a people would get to the Promised Land.  He said his eyes had seen the glory of the coming of the lord.

This became very personal to me in 1991 when I made the pilgrimage to Mecca.  I was on the plains of Mt. Arafat when I decided to climb the mountain.  When I reached the top, the only thing going through my mind was Dr. Martin Luther King and him telling us that he had been to the mountain top.

As I stood on my mountain top I look out over the plains of Arafat and saw the Promised Land. I say the Promised Land because Dr. King, in his most famous speech, said he dreamed of a land where his four little children would live in a land where they were judged not by the color of their skin but by the content of their character.   That is the vision I saw on Arafat where people of every ethnicity, every culture, every color; men, women, and children, were gathered in unity to worship the One God of us all.

I believed then, and I believe now that the mountain top Martin Luther King saw was Mt Arafat.  Islam is the only religion that has more true brotherhood and sisterhood than any other group of people whether it is a religion, a fraternity, or whatever.

Sure, there is bigotry and racism among Muslims but there is less of it than any other religion.  If you travel to any part of the world and you see a Muslim, there is instant recognition and greeting.  No one else can make that claim.  This is something we must hold on to and nurture.  It is one of the things that make this religion the greatest religion in the world.

More of Dr. Kings philosophy needs to be adapted by Muslims the world over.  Muslims must take the bold step necessary to shift world sympathy to our side.  Currently, we are looked on as aggressive barbarians and we get no sympathy from anybody.  However, people will stand up with us and protect us if they don’t look like weak fools for doing so.

The legacy of Dr. King is so important to future generations, and especially important to future generations of Muslims.  We can, and must win the battle by mental and spiritual strength – not by physical means….because we can’t.

As Salaam alaikum
(Al Hajj) Imam Abdullah El-Amin

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