Geomorphology

Cairo August 2010

Geomorphology as a tourism agent in Egypt

By Dr. Mohamed El Gazzar

Geomorphology is the study of the origin and evolution of topographic features by physical and chemical process operating at or near by earth's surface, the name stems from Greek term "GEO" means earth, "MORPHO" meaning form and "LOGOS" means discourse.

The ultimate goal in geomorphology is the understanding of surface processes and origin and evolution of land forms. Upon returning home from a long trip to north coast or Sinai Resort Beach, we often comment about how good it feels to be on the familiar ground again, yet for most of us this familiarity is at best skin deep. We know the shape of the land surface, the relative position from Mokattam Hills, Nile Valley, high ways and adjacent towns. But most of us know very little about what lies beneath these familiar features. Is our town area built on old lava flows? River deposits? Marine deposits? An old lake bed? An old landslide? Granite? Each of these would mean a drastically different geological story embracing the events of the thousands, or millions or even hundred of million years, that are recorded in the rocks and beneath the surface. How can we distinguish between these possibilities or recognize still others?

Of course, some question will apply to resorts and houses built on our coasts, along Mediterranean and Red Sea coastal plains? Is this built on mainland? Reef`? Shelf`? Slope? Or what else? A good first step would be to go out and look more closely at the familiar scene. In some areas we might see nothing but soil -loose tillable material derived principally from the decomposition of rocks. Except in regions of rugged topography, soil covers most of the land. But our main interest lies in what is beneath, and important though they are, soil conceal more than reveal regarding the bedrock, the under laying solid rock that has not lost its structure and character through decomposition, our quest leads therefore, to out crops —places where undisturbed bedrock shows through the blanket of soil or is exposedin stream banks, cliffs, road cuts or excavations. Suppose, for example the resort compound is on a fairly flat ground, a short distance from the sea front. Is it built on main land? Fault plain?? Old landslide? Coastal shelf? Slope? Etc.?

By definition, shelf represents the shallow and gradually sloping ground from the sea margin to 100 fathom line (fathom is equal to 6 feet depth), beyond which the descent to abysmal depths is abrupt and. Slope is the declivity from the offshore border of the coastal shelf of approximately 100 fathoms to sea depths, it is characterized by a marked increase in gradient.

To make even a small start toward answering these questions, we must know how to recognize the form of ground beneath the flat look of land before making any plans to build our resorts.

The first step in any investigation is to determine as many relevant facts as possible.

Followed by subsurface testing, in order to seek out new information pertinent to the morphology of the subsurface beds. Despite the abovementioned Geomorphology could be of a great help to tourism in Egypt, as Egypt hosts several hundred unique geological and Geomorphogical features and sites.

For example, the Pyramid area combining the natural and manmade. Pyramids' site should be considered as a great national treasure, where visitors will enjoy Abu Rawash Domal Structure and Hassana Dome, with its successive concentric guillies and ridges moving 70 kilometers to Gebel Quatrani in Fayoum. Tourists will also enjoy seeing large petrified logs and vertebrate remains along the road…

Erosion and Weathering

I was reading through an article written and published by the author Whitney Marian Isabelle,l9l l, title papers, 1952/1999. Although I do not know the background of the author, but I was fascinated by the article, for two main reasons, First her interest and hobby, Second out of over 180 samples, she collected more than 80 samples from Egyptian Desert.

The amazing part, is that an American lady travelled all over the Egyptian Desert to collect rock samples. In order to understand Marian's Erosion Article, we have to point-out the meaning of several terms, definitions and names mentioned in her description.

First what is the the meaning of Erosion (Latin erodere, to Cnawaway ) is a term for a way in which Geologic Agencies of movement secure and remove debris and associated organic matter.

Erosion is simply the wearing away or denudation of land masses. In a broad sense high mountains and entire continents are reduced in elevation through the removal of earth materials ocean-ward or to intermediate base levels in drainage or lake basins.

Wind Erosion:

Deflation is a term of Geomorphology used for removal of solid particles by wind ( from Latin deflare, to blow away). Wind Erosion may be divided into two types:

Deflation (actual removal of grains) and

Abrasion (the polishing and scouring of rock surfaces by wind carried grains)

Ventifact:

Is a stone which has been shaped to some extent by the abrasion of wind- driven sand. Such abrasion produces characteristic features, the most stricking being that rather flat faces, termed "Facets" are commonly developed. These meet one another and the remaining unabraded surface of the stone, if any, at sharp angles, they may be from one to perhaps eight or more facets. These though generally well polished have surface irregularities and sometimes show marked fluting or grooving, which in a homogeneous rock is aligned with wind direction. Ventifact occurs almost in desert sediments.

Pedestals or "Mushroom" type:

Rock capped with more resistant rock, e. g.: Pedestal rocks in Eastern Desert Of Egypt 30 feet high W/a caps of Ferrugincus crusts, protecting chalky materials, undercut by Exudation (by G.Schweinfurth, in Walter, l924)

Yardangs:

In ARID region where soft poorly consolidated rocks are exposed at the surface, there may be wind erosion which is both spectacular and distinctive. The yardangs consist of an elongated ridge aligned parallel to the strongest prevalent wind direction.

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