The World's Lithospheric Plates

Plate

Area (km2)

Plate

Area (km2)

Pacific

103,300,000

Scotia

  1,600,000

North American

 75,900,000

Burma microplate

  1,100,000

Eurasian

 67,800,000

Fiji microplates

  1,100,000

African

 61,300,000

Tonga microplate

    960,000

Antarctic

 60,900,000

Mariana microplate

    360,000

Australian

 47,000,000

Bismark microplate

    300,000

South American

 43,600,000

Juan de Fuca

    250,000

Somali

 16,700,000

Solomon microplate

    250,000

Nazca

 15,600,000

South Sandwich microplate

    170,000

Indian

 11,900,000

Easter microplate

    130,000

Philippine

  5,500,000

Juan Fernandez microplate

      96,000

Arabian

  5,000,000

Rivera microplate

      73,000

Caribbean

  3,300,000

Gorda microplate

      70,000

Cocos

  2,900,000

Explorer microplate

      18,000

Caroline microplate

  1,700,000

Galapagos microplate

      12,000

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نشرت فى 3 يناير 2011 بواسطة absalman

Not for commercial uses

 Hydrogeochemistry and pollution assessment of quaternary–tertiary aquifer in the Liwa area, United Arab Emirates


E. S. Al-Katheeri Æ F. M. Howari Æ A. A. Murad
Received: 14 July 2008 / Accepted: 8 January 2009 / Published online: 12 February 2009
 Springer-Verlag 2009


Abstract This study presents the data on the hydrochemical characteristics and isotope chemistry of Liwa aquifer, which could be useful to clarify the hydrochemical facies and hydrogeological regime in the study area. Electric conductivity and total dissolved solid values show that the investigated water is slightly brackish, due to the effect  of evaporation and the occurrences of evaporite rocks in the adjacent Sabkhas of Abu Dhabi. Major cations and anions arranged according to their decreasing concentrations are: Na?[Ca?2[K?[Mg?2 and Cl-[HCO3 -[SO4-2, respectively. As sodium is the dominate cation and chloride is the prevailing anion, hydrochemically the groundwater of Liwa can be classified as Na–Cl rich, predominantly chloridic. Ion concentrations increase towards the northeast and presumably coincide with the lithological sources of ions.
 Factors affecting the hydrochemistry of the  roundwater of the investigated area include the effect of weathering of soil and rocks, evaporation and agricultural activities. Stable isotopes of oxygen and hydrogen show that the shallow aquifers contain a single water type that originated in a distinct climatic regime. This water type deviates from the local meteoric water line, as well as from the Eastern Mediterranean Meteoric Water Line, suggesting potential evaporation of recharged water prior to infiltration. The waters are poor in tritium, and thus can be considered generally as indication for recharge prior to 1952. The degradation of groundwater quality can be attributed to evaporation and agricultural practices in most cases.

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نشرت فى 2 يناير 2011 بواسطة absalman

Researchers Find Mathematical Patterns To Forecast Earthquakes

 

by Staff    Writers Seville, Spain (SPX) Dec 03, 2010

These are seismogenic areas of Spain and Portugal. The study focused on the areas 26 and 27. Credit: Martinez-Alvarez et al.


Researchers from the Universidad Pablo de Olavide (UPO) and the Universidad de Sevilla (US) have found patterns of behaviour that occur before an earthquake on the Iberian peninsula. The team used clustering techniques to forecast medium-large seismic movements when certain circumstances coincide.

"Using mathematical techniques, we have found patterns when medium-large earthquakes happen, that is, earthquakes greater than 4.4 on the Richter scale," Francisco Martinez Alvarez, co-author of the study and a senior lecturer at the UPO revealed to SINC.

The research, which will be published this month by the journal Expert Systems with Applications, is based on the data compiled by the Instituto Geografico Nacional on 4,017 earthquakes between 3 and 7 on the Richter scale that occurred on the Iberian Peninsula and in the surrounding waters between 1978 and 2007.

The scientists applied clustering techniques to the data, which allowed them to find similarities between them and discover patterns that will help to forecast earthquakes.

The team concentrated on the two seismogenic regions with the most data (The Alboran Sea and the Western Azores-Gibraltar fault region) analysing three attributes: the magnitude of the seismic movement, the time elapsed since the last earthquake and the change in a parameter called the b-value from one earthquake and the other. The b-value reflects the tectonics of the region under analysis.

A high b-value means earthquakes are predominantly small in size and, therefore, the land has a low level of resistance. In contrast, a low value indicates that there are a relatively similar number of large and small seismic movements, which implies the land is more resistant.

 

 

Successful Forecast Probability Greater than 80%


"We have discovered the strong relationship between earthquakes and the parameter b-value, recording accuracy rates of more than 80%," Antonio Morales Esteban, another of the co-authors of the study and a senior lecturer at the US highlighted.

"After the calculations had been performed, providing the circumstances and sequences we have determined to be forerunners occur, we obtain a significant success probability".

The technique summarises the forecasts in two factors: sensitivity (probability of an earthquake occurring after the patterns detected occur) and specificity (probability of an earthquake not occurring when no patterns have occurred).

The results reflect a sensitivity of 90% and specificity of 82.56% for the Alboran Sea region and 79.31% and 90.38% respectively for the seismogenic region of the Western Azores-Gibraltar Fault.

That is, there is a high probability of an earthquake in these regions immediately after the patterns discovered occur (high sensitivity) and, moreover, on most of such occasions, they only occur after the patterns discovered (high specificity).

At present the team is analysing the same data using their own algorithms based on "association rules", other mathematical techniques used to discover common events or those which fulfil specific conditions within a set of events.

"The results are promising, although I doubt we will ever be able to say that we are capable of forecasting an earthquake 100% accurately," Martinez Alvarez conceded.

  1. Morales-Esteban, F. Martinez-Alvarez , A. Troncoso , J.L. Justo y C. Rubio-Escudero. "Pattern recognition to forecast seismic time series". Expert Systems with Applications 37 (12): 8333?, diciembre de 2010. Doi: 10.1016/j.eswa.2010.05.050.
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نشرت فى 21 ديسمبر 2010 بواسطة absalman

 

 Rare Earth Elements in Geology

 By Andrew Alden, About.com Guide

Defining the Rare Earth Elements

The rare earths are defined slightly differently by technologists, chemists and geologists. Chemists and technologists include 17 elements in the rare earths. These basically consist of that extra row of elements beneath the rest of the periodic table. (That row is actually meant to be inserted between lanthanum (La) and hafnium (Hf), but such an arrangement is rarely shown.) These are also known as the lanthanides or lanthanoids after the element lanthanum, which is the first of the series. The lanthanides include the 15 elements from lanthanum (atomic number 57) through lutetium (71). One of the lanthanides, promethium, is too unstable to exist in nature, but it can be manufactured in nuclear reactors. Two other very similar elements, scandium and yttrium (elements 21 and 39), are also included in the official definition. These 17 elements have important roles in metallurgy, electronics and magnetic applications.

Geologists care about actual minerals, which means the 14 natural lanthanides, but promethium is included for completeness. Geochemists usually include yttrium, for a total of 16, and sometimes scandium and thorium, to make 18 elements. Geologists abbreviate the rare earth elements as REEs.

Why are these elements lumped together? To speak chemicalese, the lanthanide series has an electron shell structure that keeps their ions at the same size within 11 percent. All of them have trivalent ions (trading three electrons to other elements), with two interesting exceptions. They all bond strongly to oxygen. So they all tend to flock together in the structure of various minerals. This is also what makes them hard for refiners to separate.

Rare Earths: Not Rare, Not Earths

The rare earths got their name starting in the 1700s, but the label stuck even when they were found to be metallic elements and not especially rare. Chemists first discovered them as oxide compounds (thus "earths"), difficult to reduce to metal, in obscure minerals (thus "rare"). It took a century to isolate all of them. Nowadays the historic term is still the handiest way to refer to them.

Rare earths are not as rare as the name implies. In cosmic terms, they're pretty rare, like most elements. Only one of them, cerium (Ce), is more abundant than 1 part per million in the whole Earth (core, mantle and crust). However, they tend to rise to the top because their atoms don't fit into the most common minerals—thus geochemists list them in the incompatible elements. In the upper continental crust, total REEs amount to around 200 parts per million and are more common there than copper, chromium, lead, zinc and tin.

Rare Earth Minerals and Mines

The REEs can tuck themselves away to a small extent in garnetzircon and titanite. The phosphate minerals apatitemonazite and xenotime can have high REE contents; so can the silicate minerals allanite and eudialyte.

If conditions concentrate them enough, the REEs prefer their own peculiar minerals like bastnasite (a carbonate), euxinite and samarskite (both titanates). One of those conditions is met in pegmatites, the last liquid dregs of granite intrusions. That's where the REEs were first found and first mined. Another is in highly alkaline (sodium/potassium-rich) magmas andcarbonatites. Both of these rare rock types form by repeated partial melting of deep crustal rocks, the geochemical equivalent of separating cream from milk. Until recently, most REEs were mined from these kinds of rocks.

Another way that REEs become concentrated is by removing everything else. This appears to have happened in a large area of southern China where granite was weathered into thick deposits of clay: laterites. The clays there have absorbed minable amounts of rare earths, and today the Chinese "ion-absorption deposits" are the world's largest source of REEs. Between them and a large iron mine in northern China where REEs are a byproduct, China accounts for more than 90 percent of world production.

Rare Earths in Geology

Geologists use REEs to trace the histories of rocks and magmas. The sizes of REE ions are slightly larger in the light REEs (elements 57–62) and slightly smaller in the heavy REEs (elements 63–71). This difference allows them to slowly become enriched or excluded as they enter melts of various compositions. When you make graphs for various rocks showing the levels of all the REEs, some graphs have a line sloping up to the right (heavy) while others slope up to the left (light).

Two of the REEs offer extra information. Cerium (Ce, element 58) usually has a +3 valence, like the other REEs, but can also be oxidized to a valence of +4. In that case it behaves differently under oxidizing and reducing conditions, and it also substitutes for zirconium in the widespread mineral zircon. Both of these may leave a record in REE graphs called a "cerium anomaly."

Europium (Eu, element 63) has the option of a +2 valence, in which case it can swap places with calcium in feldspar minerals. At the same time, divalent Eu is excluded to a lesser extent from other minerals. A "europium anomaly" is typically a sign that a magma has lost or gained crystals of plagioclase feldspar. On REE graphs, these anomalies show up as nicks or peaks in an otherwise straight line. They are considered useful for distinguishing rocks of mantle and crustal origins.

Although mining and refining REEs is still a difficult undertaking, modern lab equipment and techniques have made measuring REEs in rocks almost as easy as sorting marbles. The elements that once perplexed chemists and still frustrate refiners are enlightening geologists today.

For much more information, see the U.S. Geological Survey's Scientific Investigations Report 2010-5220, "The Principal Rare Earth Elements Deposits of the United States," my source for much of this article.

 

 

 

 

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نشرت فى 13 ديسمبر 2010 بواسطة absalman

The Nuclear Core: A bedazzled scientist proposes a deep-Earth theory no one needs

By Andrew Alden

Today's geoscientists have a working theory of the deep Earth. What that means, in essence, is that it yields fruitful questions—problems to work on using supercomputers, high-pressure equipment, and analyses of rocks from everywhere including outer space and other planets. Is a dazzling new theory like Marvin Herndon's what we need?

Herndon, an independent geophysicist, made a splash in the August 2002 issue of Discover magazine with his idea that a ball of uranium minerals sits deep in the Earth's core, a gigantic natural nuclear reactor.

The discover article is a fair introduction, but Herndon's own Web site nuclearplanet.com reproduces earlier papers that Herndon has published. These are indispensable for understanding his hypothesis. It has several plausible elements, and the state of current knowledge permits it as far as I can tell. But I have my doubts as to whether his hypothesis is a fruitful one.

The Herndon Thesis

Briefly Herndon's story is this: the Earth s iron core formed with a goodly share of radioactive uranium, which combined with sulfur to make an ultra-dense compound. The uranium settled to the center of the core, where it eventually formed a mass big enough to sustain a supercritical nuclear reactor. Not just that, but it functions as a breeder reactor, creating more nuclear fuel than it burns. This provides the energy needed to generate the geomagnetic field, a problem that has challenged scientists since the 17th century when Edmond Halley proposed the first theory of geomagnetism.

What do I like about it? One thing: the uranium sulfide angle. Uranium is classified as a lithophile element, which like calcium, magnesium and other elements dislikes iron. The composition of the core is almost entirely iron, with an unknown lighter element mixed in. The lighter element could be sulfur or oxygen or both, so it's plausible that the lithophile elements in the young core would form sulfides and separate out as an immiscible liquid. The sulfide droplets would rise and settle in the D ' layer at the top of the core. But apparently uranium monosulfide, unlike other lithophile sulfides, is denser than iron. So Herndon argues that it would form a ball in the core's center.

Once you accept Herndon's hypothesis, a host of tempting consequences follow, and the bulk of his papers (not to mention the articles about his papers) follow that temptation to entertaining effect.

Unanswered Questions and Unlikely Answers

But I have two quick questions before I, for one, would take it further. First, would the uranium sulfide separate from other sulfides? I don't see why it would, if they are liquids. Second, would the uranium sulfide sink? Gravity is essentially zero in the inner core, and we know the inner core is solid. Herndon is captivated by a real example—the actual natural reactor that once existed at Oklo, in the African nation of Gabon, some 1800 million years ago. I don't blame him; it's a geologic wonder. The Oklo example proves that a natural fission reactor can exist, under certain unusual conditions near the Earth's surface. But it is not evidence for anything in the Earth's core.

It's one thing to look at that example and try to imagine other ways such a thing could occur. But it's another for Herndon to imagine reactors everywhere he sees a mystery—for instance, in the excess energy output of Jupiter and Saturn and even in the lukewarm core of the Moon. It is his universal solution, in search of a problem.

An Unneeded Theory

So I return to the opening question: Do we need this dazzling new theory? Not really. We are already making computer models of the geomagnetic dynamo (Gary Glatzaier currently leads the pack) that don't need a big ball of uranium to make them work. There is enough uncertainty in our picture of Earth's internal heat that Herndon's solution isn't superior. And our notions of how the Earth and solar system formed don't require, or even favor, his scheme.  For a summary of the mainstream view, see this talk that David Stevenson gave to the 2002 SEDI Symposium in July. And in another talk at that meeting, William McDonough specifically addressed the problem of uranium in the core.

The great conversation of science is on a different page. Everything can change, it's true—but not today.

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Giant Crack in Africa Will Create a New Ocean

By LiveScience Staff

 A 35-mile rift in the desert of Ethiopia will likely become a new ocean eventually, researchers now confirm. The crack, 20 feet wide in spots, opened in 2005 and some geologists believed then that it would spawn a new ocean. But that view was controversial, and the rift had not been well studied.  

A new study involving an international team of scientists and reported in the journal Geophysical Research Letters finds the processes creating the rift are nearly identical to what goes on at the bottom of oceans, further indication a sea is in the region's future. The same rift activity is slowly parting the Red Sea, too.

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نشرت فى 20 أكتوبر 2010 بواسطة absalman
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نشرت فى 25 سبتمبر 2010 بواسطة absalman

 

تقليل المخاطر الطبيعة علي بعض مواقع الآثار بهضبة أهرامات الجيزة والواحات الخارجة، الصحراء الغربية ، مصر وذلك بدراسة الظاهر الجيولوجية

مقدمة

          لما كانت الآثار المصرية تمثل ثروة قومية وتراثا ثقافيا عظيما، ولما كان الحفاظ عليها يمثل هدفا ساميا يخدم الاقتصاد القومي والتراث  الثقافي والحضاري المصري، فقد تقدم المكتب المصري للاستشارات الجيولوجية إلي اللجنة القومية المصرية للتربية والعلوم والثقافة (اليونسكو) باقتراح لإجراء دراسة للظواهر الجيولوجية لبعض مواقع الآثار بهضبة أهرامات الجيزة والواحات الخارجة وذلك لتقليل المخاطر الطبيعية علي تلك المواقع الأثرية، وقد تمت  الموافقة من قبل اليونسكو علي إجراء الدراسة وأدرجت تحت مشروع: . (EGY 18322409)

وكذلك تم الحصول علي موافقه من المجلس الأعلى للآثار المصرية علي تنفيذ هذه الدراسة بتاريخ 18 سبتمبر 2005م.

 

          وافقت اللجنة القومية المصرية للتربية والعلوم والثقافة (اليونسكو) علي خطة ومراحل الدراسة التي اقترحها المكتب المصري للاستشارات الجيولوجية والتي اشتملت علي أربعة مراحل هي: مرحلة الإعداد والتجهيز – مرحلة الدراسة الميدانية للظواهر الجيولوجية – مرحلة الدراسة المعملية ومرحلة إعداد التقرير النهائي.

 

الخلاصة

          يشتمل هذا المشروع علي دراسة الظواهر الجيولوجية في بعض مواقع الآثار بمنطقتي هضبة أهرامات الجيزة والواحات الخارجة بالصحراء الغربية، وذلك بغرض تقليل المخاطر الطبيعية علي تلك المواقع الأثرية الهامة. وفي خلال هذه الدراسة تم معالجة الصور الفضائية التفصيلية لتلك المواقع وذلك لعمل خرائط جيولوجية مبدئية، وخلال الدراسات الميدانية تم التحقق من الوحدات والتراكيب الجيولوجية المستنبطة لتحويل تلك الخرائط الأولية إلي خرائط جيولوجية والتي تحتوي علي معظم الظواهر الجيولوجية الهامة. وقد تم فحص المواقع الأثرية وتجميع الملاحظات الميدانية وخاصة العوامل التي تسبب تدهورا لتلك الآثار وتصويرها كلما سمحت الظروف.

          وقد اتضح خلال  هذه الدراسة أن المخاطر الطبيعية في هضبة أهرامات الجيزة يتحكم فيها عدد من العوامل أهمها نوعية الصخور السائدة وطبيعة صخور طبقات الأساس ومناطق الصدوع والشقوق. وتجدر الإشارة إلي أنا بعضا من هذه الصدوع يحتمل أن تكون من النوع القادر (Capable faults) أو النشط، زيادة علي ذلك وجود نطاقات شديدة التغير مثل ظاهرة (Karstification phenomenon)  والكهوف في طبقات الحجر الجيري نتيجة لتأثير التراكيب الجيولوجية والتغيرات الجيوكيميائية وحركة المياه الجوفية والأمطار والرطوبة وعوامل التلوث من البيئة المحيطة تشكل مخاطر أخري لا يستهان بها. كذلك اتضح وجود مخاطر أخري نتيجة لعمليات التعرية والتجوية علي مجمع الآثار في منطقة أهرامات الجيزة.

 

          ونتيجة للمخاطر التي تم تحديدها من خلال هذه الدراسة في منطقة هضبة الأهرامات يمكن التوصية بما يلي:

·   القيام بتثبيت ومعالجة وتدعيم المواقع الضعيفة والتي لوحظ وجود العديد من الكتل الصخرية الآيلة للسقوط علي حافة الهضبة الصغيرة القريبة من هرمي خفرع ومنقرع. كما يجب معالجة نطاق الصدع المتجه شمال غرب – جنوب شرق والذي توجد به العديد من الشقوق التي تقطع طبقة الأساس وتضعفها في الجزء الشمالي الشرقي لهرم خوفو.

·   تطبيق بعض الدراسات الجيوفيزيقية لتحديد مسارات الصدوع وخاصة التي تضرب في اتجاه شمال غرب – جنوب شرق وكذلك مواقع وجود الكهوف في هضبة الأهرامات. وترجع أهمية تلك الدراسات في أنها تساعد علي إيجاد أحسن الحلول لعمليات الترميم وتقوية مناطق الضعف وتلاشي المخاطر المحتملة في المستقبل.

·   دراسة التراكيب الجيولوجية الحديثة (Recent tectonics) . وتساعد هذه الدراسة علي تحديد الصدوع المحتمل ارتباطها بالزلازل المؤثرة والتي تمثل خطرا حقيقيا علي مجمع الآثار بهضبة الأهرامات. ويجب أن تشمل تلك الدراسة المقترحة مسح للصدوع السطحية لتحديد الأنواع النشطة منها، وإذا تم التحقق من وجود صدوع نشطة فإنه يتحتم تحديد أعمارها.

·   أما بالنسبة لأبو الهول، فقد أوضحت الدراسة أنه قد تم نحته في طبقات من الحجر الجيري المارلي والمارل، وتتصف هذه الصخور بعدم الصلابة (Soft rocks)  ، وأنها قد تأثرت بالعديد من الشقوق والفواصل المتقاطعة. زيادة علي ذلك فإن أبو الهول نفسه قد تأثر بالعديد من الشقوق، وتجدر الإشارة بأن تلك الشقوق والفواصل تمثل خطرا حقيقيا علي أبو الهول بالإضافة إلي عوامل التدهور الأخري. ومن ناحية أخري فإنه في حالة حدوث زلزال ولو بقوة متوسطة بالقرب من منطقة الأهرامات  فإن أبو الهول سوف يكون أكثر الآثار تضررا. ومن هنا تظهر أهمية التوصية بتحديد مواقع الصدوع النشطة  (Capable faults)  في الجزء الشرقي لهضبة الأهرامات.

·   ومن الملاحظات الهامة نتيجة لدراسة الظواهر الجيولوجية حول منطقة أبو الهول مخاطر المياه الجوفية حيث لوحظ تشبع بعض الأجزاء السفلي منه بالرطوبة، وذلك يرجع إلي موقع أبو الهول علي مستوي منخفض بالنسبة لهضبة الأهرامات، بالإضافة إلي قربه من قرية نزلة السمان العامرة بالسكان. لذلك نوصي بملاحظة مستوي منسوب المياه الجوفية والحفاظ عليه عند مستوي آمن لدرئ مخاطر المياه الجوفية وتأثيراتها السلبية علي أبو الهول.

 

أما عن منطقة الواحات الخارجة، فقد تم دراسة الظواهر الجيولوجية في عدة مواقع أثرية اشتملت علي معبد هيبس ، ومعبد النادورة البجوات، ومعبد الغويطة ومعبد قصر زيان. وقد أوضحت هذه الدراسة أنه من أهم الظواهر المؤثرة، والتي يمكن أنا تمثل بعض الأخطار علي تلك المواقع الأثرية، هي المياه الجوفية ( خاصة في موقع معبد هيبس) وطبيعة التربة ونوعية المواد المستخدمة في البناء والكثبان الرملية والشقوق والفواصل، بالإضافة إلي العوامل البيولوجية. وبناءا علي دراسة الظواهر الجيولوجية وتفحص البيئة المحيطة بتلك المواقع الأثرية بمنطقة الواحات الخارجة، يمكن التوصية بما يلي لتقليل المخاطر علي تلك الثروة القومية من الآثار:

·   لابد من دراسة وضع المياه الجوفية بالتفصيل في منطقة معبد هيبس، والعمل علي الحفاظ علي مستواها عند الحد الآمن بحيث لا تتضرر منها مشآت المعبد والذي يتم ترميمه حاليا (2005) ويتم ذلك بحجب حركة المياه الجوفية ومياه الرشح من الأراضي المنزرعة حوله، وذلك بعمل بعض الحواجز العازلة علي أسس تقنية سليمة. كذلك يتم تخفيض مستوي المياه الجوفية في التربة الموجودة تحت المعبد، ولكن لا بد أن يتم عمل ذلك علي أساس علمي وهندسي بحيث لايتسبب في أي انهيار في تربة الأساس نتيجة لعدم التوازن في الضغوط في بيئة المعبد. ويقترح تقوية طبقة الأساس بالمعبد وخاصة أنها تربة طينية ذات سمك كبير.

·   إجراء دراسة تفصيلية عن الكثبان الرملية بالواحات الخارجة مع التركيز علي الكثبان الموجودة بالقرب من المواقع الأثرية ويجب أن تشمل تلك الدراسة: ديناميكية الرياح ومعدل تقدم الكثبان الرملية في جميع اتجاهات والعوامل التي تتحكم في تجمع تلك الكثبان وأثر تلك الكثبان علي المنشآت الأثرية ومشروعات التنمية.

·   تطبيق جميع التقنيات الممكنة لتقليل مخاطر العوامل البيولوجية علي تلك الآثار. ويرجع ذلك إلي أنا التأثيرات البيولوجية تعتبر من أهم المخاطر التي تتعرض لها الآثار في تلك المنطقة وخاصة النقوش والكتابة، وقد لوحظ أن بعضا منها قد دمر بالكامل بسبب التأثيرات البيولوجية.

·   وفي نهاية التقرير العلمي لهذه الدراسة، تم وضع خطة للحفاظ علي تلك الآثار وصيانتها وترميمها في موقعي  هضبة الأهرامات والواحات الخارجة. وتشتمل هذه الخطة علي المراحل  اللازمة لصيانة المواقع الأثرية بدءا من الدراسة التاريخية للأثر وجمع البيانات المطلوبة والدراسات المعملية والحقلية حتى عمليات الصيانة والترميم للوصول بالأثر إلي حالة قريبة من حالته الأصلية بقدر الإمكان. وكذلك تم التركيز في هذه الخطة علي أبو الهول وذلك لإنقاذه من التدهور والحفاظ عليه. وقد اشتملت هذه الخطة المقترحة أيضا علي صيانة وترميم مواقع الآثار بالواحات الخارجة والحفاظ عليها من التدهور، ومن أهم هذه المواقع معبد هيبس، النادورة، البجوات، الغويطة وقصر زيان. وتعتبر هذه الخطة ذات نفع كبير ويمكن تطبيقها بسهولة، كما تفيد في الحفاظ علي الآثار وميكنة البيانات الخاصة بهذا التراث الحضاري والثقافي. 

ملاحظة: لمزيد من المعلومات اتصل بي علي: [email protected]

 

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CONTENTS

Summary ................................................................................................................................... 1

Methods of evaluating ore processing and effluent treatment for Cigar Lake Ore at the Rabbit Lake Mill   5

C.R. Edwards

Present and future mine effluents management at  Zirovski Vrh uranium mine............................................15

Z. Logar, B. Likar, I. Gantar

Technical treatment options for the mill effluents of the Los Gigantes complex .................................................27

A.R. Asenjo

Waste monitoring of the uranium ore processing activities in Romania ................................................... 41

L. Nica

Purification of waste effluents from uranium mines and mills in Ukraine ............................................................. 51

S. Bezrodny, Y. Bakarzhiyev, B. Pesmenny

Application of nanofiltration to the treatment of uranium mill effluents.................................................................. 55

S.J. Macnaughton, J.K. McCulloch, K. Marshall, R.J. Ring

Prediction of pollution into ore bearing acquifer from ISL-site.......................................................................... 67

V. Dolgopolov, P. Kayukov, L. Vyatchennikova, I. Shishkov

Research on the removal of radium from uranium effluent by air-aeration hydrated manganese hydroxide adsorption.................................................................... 93

Jianguo Zhang, Chen Shaoqing, Qi Jing

Effluents from a waste rock deposit of a former uranium mine in axony/Germany — Mass flow balance of water and dissolved solids ...................................................107

D. Biehler

Remarks on the radon gas release from dumps of uranium mining ...........................................................117

J. Hartsch, J. Pinka

بعض من تلك المقالات محملة بالموقع للمعرفة الثقافية وليس بأي غرض تجاري

 

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نشرت فى 20 سبتمبر 2010 بواسطة absalman

 

Mineralogy and hydrochemical characteristics of the late marshes and swamps of Hor Al Hammar, Southern Iraq

K.M. Banata, F.M. Howarib,,1, M.B. Abdullahc

aDepartment of Earth and Environmental Sciences, Yarmouk University, Irbid, JordanbGeology Department, UAE University, P.O. Box 17551, Al-Ain, UAEcGeology Department, Faculty of Science, Baghdad University, Baghdad, Iraq

 

Abstract

This study presents unpublished results on the hydrochemical characteristics of swamps (Hor) of Al Hammar, which could be useful for the intended restoration efforts. Electric conductivity and total dissolved solid values show that the investigated water is slightly brackish, due to the effect of evaporation and slightly acidic due to organic and biological activities producing sulfuric acid. Major cations and anions arranged according to their decreasing concentrations were: Na1+4Mg2+4Ca2+4K1+; Cl14SO4 24HCO3 1. Hydrochemically the water of Hor Al-Harmmar can be classified as: Ca2+–Mg2+–Na1+–SO4 2–Cl1 type. The study found that upon a continuous evaporation gradient, the water tended to approach the seawater type. Ion concentrations, except for Ca2+, increased towards the middle part of the Hor (Al-Shafi) and are explained as evaporative concentrations. The different behavior of calcium may be explained by the consumption of calcium sulfate by the organisms living in the Hor to build up their shells and skeletons. Factors affecting the hydrochemistry of the water of the Southern Iraqi swamp include the effect of seawater, weathering of soil and rocks, evaporation, biological activity, chemical precipitation of calcium carbonate, and the effect of clay minerals in the investigated water. The reported results could serve as background information needed for restoration of the marshland and swamp of Southern Iraq.

البحث الكامل منشور بمجلة: Journal of Arid Environments 65 (2006) 400–419

 

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نشرت فى 20 سبتمبر 2010 بواسطة absalman

 

Depositional and diagenetic processes of Qa Khanna playa, North Jordan basaltic plateau, Jordan

F.M. Howari a,*, K.M. Banat b, Y.A. Abu-Salha b

a Environmental Science Program, College of Arts and Science, The University of Texas of the Permian Basin, 4901 East University, Odessa, TX 79762, United Statesb Department of Earth and Environmental Sciences, Yarmouk University, Irbid, Jordan

a b s t r a c t

The present study explored mineral occurrences and sediment characteristics of playas from northern Jordan and explained depositional and diagenetic processes as reflected from bulk chemistry and sedimentary structures. Mudcracks of different sizes and shape patterns, laminations, intersediment vesicles,

and bioturbation pipes are the main sedimentary structures. Plagioclase, olivine, orthopyroxene, nepheline and other opaque minerals are all of detrital origin, and are derived from the basaltic bedrocks surrounding the studied playa. Evaporites are very rare; they are represented only by trace amounts of gypsum. The identified clay minerals in the clay fraction of the studied sediments, arranged according to their decreasing abundances are palygorskite, illite, kaolinite, smectite and chlorite. The elemental abundances were tied to clay, CaCO3 and nearby igneous rocks. The type of clay minerals, the high pH values of the studied sediments, and the considerable incorporation of Mg and K in palygorskite and illite respectively, may strongly reflect a high evaporative and alkaline environment under arid to semi-arid conditions in an ephemeral lake of the Qa Khanna. Concentrations and distributions of both major and trace elements are essentially controlled by the clay mineralogy and the calcium carbonate content; Ca is mainly incorporated in the CaCO3, which is either generated authigenically or by aeolian deposition.

Fe and K are incorporated and fixed by illite under an evaporative and alkaline environment. Mg is incorporated in palygorskite while Mn is adsorbed on various clay minerals. Sr substitutes for Ca in the aeolian CaCO3 and its presence in the studied sediments is independent of the prevailing conditions during the playa evolution. Rb substitutes for K in illite under the prevailing chemical conditions in the studied playa.

 N.B.: The complete article is published in: Journal of Asian Earth Sciences 39 (2010) 275–284

 

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نشرت فى 20 سبتمبر 2010 بواسطة absalman

 

Environmental impact and natural hazards on Kharga Oasis monumental sites, Western Desert of Egypt

A.B. Salman a,*, F.M. Howari b, M.M. El-Sankary a, A.M. Wali c, M.M. Saleh d

a Nuclear Material Authority, P.O. Box 530, El-Maadi, 11431 Cairo, Egypt

b Environmental Science Program, College of Arts and Science, The University of Texas of the Permian Basin, 4901 East University, Odessa, TX 79762, USA

c Faculty of Science, Department of Geology, Cairo University, Egypt

d Faculty of Archaeology, Department of Conservation, Cairo University, Egypt

a r t i c l e i n f o

Article history:

Received 19 October 2009

Received in revised form 17 March 2010

Accepted 18 March 2010

Available online 30 March 2010

 

a b s t r a c t

Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The studied sites include the Hibis, EI-Nadura, EI-Ghueita and El-Zayyan temples as well as El-Bagawat Cemetery.

The present study found that natural hazards have remarkable impacts on these sites. The impact of weathering processes, encroachment of sand dunes, stability of foundation beds and shallow groundwater seepage were documented. The present study found that humidity, temperature, sunlight and water content conditions seem to be favorable for biodegradation as evidenced by the presence of algae, bat blood and bird excretions. The radioactivity levels at the investigated sites are also measured via gamma-ray spectrometry.

Sand dunes in the area pose a serious natural threat to the monumental sites. Active sand dunes are rapidly encroaching upon the components of these monuments, partially covering some monuments such as El-Ghueita Temple. These dunes load wind storms with fine sand particles. This causes wind erosion through sand blasting of these sites. Some monuments, such as EI-Nadura, EI-Ghueita and El-Zayyan temples were constructed on a suitable hard sandstone ground, whereas others, such as the Hibis Temple, were constructed on unsuitable soft shale ground in relatively topographically low area. The impact of the unstable foundation and shallow groundwater levels have caused severe structural damage as evidenced by tilted columns, cracked walls and salt-crystal growth in the porous building stones. These destructive elements threaten some other temples in Kharga Oasis and will eventually cause total physical collapse. Although rain is rare in this area, it can form a real threat to mud brick monuments such as El-Bagawat Cemetery. The natural radioactivity sources resulted in an annual effective dose equivalent values averaging 0.20, 0.13, 0.09 and 0.07 mSv/year for the monumental sites at Hibis, El-Nadura, El-Ghueita and El-Zayyan, respectively.

 

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