1.07k likes | 2.1k Views
Geology Geology = Earth Science What is the meaning of geology ? Geology is the study of Earth, includes, Chemical and Physical Properties, Earth Creation, Inner and Outer Processes Affected it, Since Its Creation To Present Day. Geological Branches
E N D
Geology Geology = Earth ScienceWhat is the meaning of geology ?Geology is the study of Earth, includes, Chemical and Physical Properties, Earth Creation, Inner and Outer Processes Affected it, Since Its Creation To Present Day.
Geological Branches A-Basic geology:-B-Connected Branches:-C- Applied Geology:- 1- Crystallography . 1- Geochemistry. 1-Economic Geology. 2- Mineralogy. 2- Geophysics. 2-Engineering Geology. 3- Petrology . 3-Geomorpholpgy. 3-Petroleum Geology. 4- Paleontology . 4-Structural Geology. 4-Hydrogeology. 5- Stratigraphy . 5-Photogeology. 5-Mining geology. 6- Dynamic geology . 6-Oceanography. 6-Agricultural geology. 7- Historical geology . 7- Field geology. 22 7-Miltary geology. 8-Glacial geology. 9-Volcanology. 10-Cosmic geology. 11-Geodesy. The relationship between geology and other sciences 1-Physics-----------Geophysics---------- 1-Gravity Method. 2-Magnetic Method. 3-Seismology. 4-Electrical Method. 2-Biology --------------- Paleontology ------Remaining of Animals and Botanical. 3- Chemistry ----------- Geochemistry. 4-Engineering ---------- Engineering geology. 2
History of Geology 1-Humorous 600 B C:-He put an idea about the shape of Earth and he descript the earth as a disc surround by water. 2-Aresto 384-322 B C :-He is provided that the Earth is a ball by scientific method . by observation he is noticed that, the matter collection is to the same center . 3-Herodotus 424-484 B C:-The first scientist who noticed the remaining of Botany and Animals on the mountains of earth crust , which is prove that the present mountains were oceans surfaces in the deep past.. 4-Khalelo 1546-1642 C :- He is Provided the motion of earth around its axis is from west to east . 5-William Smith 1769-1839 C :-He is the first scientist whose established stratigraphy and correlation by its contents of fossils and he was drawing a geological map for e England in 1845 . History of geology- Arab scientists 1-Ibin Siena died 1049 :-The first one who is established the geology and studied also the minerals . 2-Al Bairony died 1271 :-He is described an expensive crystals minerals in scientific methods . 3-Alrazi died 1369 :-He is divided the minerals into six groups in his book (secrets of the secrets) . Other scientistsuch as JahithTakishkhandySarkhasyet. 3
The site of Earth within Galaxy (Milky Way) 88 D SUN 364.25 D Mercury Venus 11.86Y Earth 82.02Y Mars 225D Jupiter 247.7Y Saturn 1.88Y Uranus Neptune 29.46Y Pluto 164,8Y D = Day Y = Year 4
Hypothesis of Earth Creation and Global System 1-Buffoon Ht 1707-1788 (France) :-The first scientist, which is put an idea for the source of earth in his book, (The Natural History). The idea is the present global system results from very hard attack between the sun and one of big solar mass, then many big masses are separated and swimming in Space to different distances around the sun controlled by Sun gravity. 2-Kants Ht 1755 (German) :-This hypothesis proposed that the whole solar system was consist of very much of small solid parts swimming in the global system in high speed. This parts were collected together by gravity with high heating due to attachment between it, which result very hot gases (NEBULA) rotated around together in great speed. This conditions gives a hot gas rings and by the, out of center force forming our Sun system. 3-Nebular or Lab Lass Ht 1796 France:-The solar system in the beginning ( NEBULA) was occupied about four sizes of the solar system. With time, there are heating loss ,contraction which results rotation with high speed around (NEBULA) axis .at same time the out of center force makes a cycle with irregular out line which results a big masses named the solar system. later the contraction of masses with continuous cooling and rotation makeup the solar system. 4-Other hypothesis:-a-Planetesimal hypothesis (Chamberlin- and Moulton American- Geologist 1905). b-Gaseous Tidal Ht (Jemis and Jeffery 1929). New theories in origin of solar system 1-The Nuclear Explosions Theory 1931:-This Theory suggests that, a part of Global Space is composed of Dense Gases (Protogalaxy). With time these gases collects together to form ( Nuclear Cells). So at same time Great explosions is happened for global bodies which is separated it faraway from its original space to form (Global Galaxy). After that the Gases are began cooling with space reduction and rotation, then finally a new birth for solar Galaxy in space, before about 10-13 Billion years ,while Gases condensation is create about 250 million years ago. 2-Great Gas Cloud Theory 1942 -1948:-In the beginning the Sun and Stars were as Global cloud consist of Gases and dust. it is condensed by stars light pressure, dust and gases gravity forces. This conditions lead to create rotation state to form (Primary Nuclei), The remanent clouds stays in the center forming the Sun. Later this theory considered the Electromagnetic force is played as important agent in global system. 5
Earth Creation Since 6 Billions years , the Earth was separated from Sun. So by rotation , continuous cooling ,the mass of gas became Ball-shape covered by solid crust called (Earth crust ), while the inner of Earth still in Fusion state. There are four stages at Earth Creation:- 1-Anhydric Period:-In this period the elements consists Earth differentiated into three zones ( Gases and liquids Earth crust, Mantle and Core) depend on gravity, rotate around Earth,( mass of gases and liquids are the outer shall) as :- a-Gases and Liquids zone. b-Silicate-Sulfides zone--------Outer part (Earth crust). c-Iron- Nickel zone-------------Inner part (Mantle and core). -The cooling time of Earth crust is take about 900-1000 million years. . 2-Oceanic Period( water Basins):-This period of Rains fall is due to the critical Temperature of water, which is form water Vapor, then Rainfall within about 300- 400 million years. 3-Contraction Period:-A big water Basins such as oceans seas are the result of continuous cooling for earth crust, association with mountains building within about 1000 -1700 million years. 4-Continintal Drift period:-There are many evidence says that, the Dry parts of earth (Crust) was connect in the ancient time. Then by Earth Dynamic (Hypogene Processes) the crust moves along the fusion zone of Earth (upper part of mantle-Asthenosphere) which is result sedimentary basins due to the big Oceanic sediment. Conclusions:- a-The Earth crust and air cover were buildup at first stage. b-The water cover was buildup at second stage. c-The ancients evidence of life is before 2500 million years. 6
Nature of Earth A-Dimensions of Earth :- 1-The polar Radius =6357 kilometre . 2-Equator Radius =6378 kilometre . 3-Polar Circumference = 6357 km x 2 x 22 ÷ 7 = 40 009 kilometre . 4-Equator Circumference = 6378 km x 2 x 22 ÷ 7 = 40 077 kilometre . 5-Area of earth surface = 510 000 000 square kilometre. 7-Dry area of earth surface = 29,22% = 149 000 000 square kilometre. 8-Water area of earth surface = 70.78% = 361 000 000 square kilometre. 9-highest point of dry area at earth surface = 8848 metre (Everest mountains crest). 10-Avverage of earth surface = 840 metre. 11-deeper point of ocean = 11033 metre (Mariana trench). 12-Average of ocean deep = 3808 metre. Polar Dimension Equator 7
sial 0C 5 - 60 km Crust sail Sima Crust 5 - 60 km Sima 870 C Upper Mantle Conrad Discontinuity Upper Mantle Conrad Discontinuity (AsthenoSphere( Peridotite Rocks Moho Discontinuity Peridotite Rocks Moho Discontinuity Lower Mantle Mantle (Mesosphere) Mantle Lower Mantle 35 - 2900 km Pallasite Rocks () (peridotite=Fe) Gutenberg Discontinuity 2 200 C Gutenberg Discontinuity Upper Core Upper Core C R O S S S E C T I O N I N E A R T H 2900 km Fe = 90% Ni = 10% Core Lowe Core Core 2900 - 6370 km Iron+Ni Lower Core Earth Crust Density= 2.85 gm/cm3 Mantle Density = 4.53 gm/cm3 Core Density= 10.7gm /cm3 6370 km 6 000 C 8 8
Earth Covers1-Atmosphere cover. 2-Hydrosphere cover. 3-Biosphere cover. 4-Lithosphere cover. 1-Atmosphere cover :-It is Air cover, surrounding Earth. Its thickness about 316 km . atmosphere is consist of many Gases like :- a- N2 about 78% b- O2 about 21% c- Ar about 0.93 d- CO2 about 0.03% e- H2 about 0.011 99.124% About 35 PPM are inactive Gasses such as Neon, Helium and Ozone are present in Atmosphere . 1-Atmosphere Cover:-Atmosphere cover is divided into:- A-Troposphere layer :- 1- Elevation of Troposphere layer is about 8 - 18 km . 2- Temperature is decreasing about 6 ْC every 1 km rising 3-This layer is consist of homogenous gases, water vapour,CO2and dust. B-stratosphere layer :- 1- The second layer with elevation about 50- 80 km . 2- The lower part of this Layer is (50 km) named Ozone layer . 3- Stratosphere temperature is increase to 35 ْC with no storm. 4- Stratospheric Pressure is 0.5 mm mercury (1/1520) of Normal Pressure. C-Ionosphere Layer:- 1- The elevation is about 80 – 316 km 2- the Ionization is due to the affects of the Cosmic and Ultra violent Rays, so it is good Conductor for Electricity. 3- Many of (Meteors and Meteorites)are Burn with Traffic in this Layer. 4- This Layer is Good medium to cross Radio and Wireless Waves. D-Exosphere layer :- The highest layer in the Atmosphere ,so it is extend as far as entrance of outer space . Meteor:- It is Solid, Small masses swimming in the space, but when it falls on the Earth it called (Meteorites). 9
2- Hydrosphere Cover:- Hydrosphere is consist of Oceans, Seas, Lakes, Rivers and Ground Water. The Water of Oceans, Seas Contains (Constant Weight) 35 gram per letter of different Salts, commonly of Sodium Chloride type (NaCl). Rivers Water:-contains generally less than 1 gram per letter Salts commonly of calcium bicarbonate and calcium carbonate Water type. Ground water:-quality of ground water depends on the ground water source, host Rocks and the migration of the ground water. Groundwater contains a wide variety of salts. Ground water may be Fresh water ( less than 1 gram per letter) or Saline water(More than 10 gram per letter). 3-BiosphereCover:- Biosphere:-It is not true Cover. It is consist of Animals and Botany Creatures which deals with Hydrosphere, Atmosphere and the upper part of Lithosphere cover. Biosphere plays important rule in the difference changes on Earth Crust. 4- Lithosphere Cover:- The thickness of Lithosphere (Earth Crust) is from 5 km in the Oceans to 60 km in the Mountain regions. The Wells drilling operations in the Earth Crust still about 10 km depth. Earth Crust consist of Sedimentary, Igneous and metamorphic Rocks, covered by Soil in many regions of Earth. The Soil is a Result of Disintegrate ,Erode of all kinds of Rocks with different thickness depend upon many factors. The Rocky layers of Earth Crust are found below Soil and it is divided into tow Layers depend on Minerals consist it:- 10
Earth Crust – sial and Sima Layer Sial Layer:-It is the upper part of Earth crust .Its thickness between 2-15 km, Density about 2.8gm /cm3 . Sail is consist of light colours Granitic Rocks ( Aluminium Silicate). Sial Layer is thick at Land while it is thin or absent at Oceans. Sima Layer:-It is the lower part of Earth Crust. Its thickness about 20-25 km, Density about 3.4gm /cm3 . Sima consist of Magnesium Silicate. The upper part of this layer is Crystalline but the lower part is uncrystalline (classy texture). Conrad Discontinuity:-Interference zone which is separated between Sial and Sima. Sea Level Conrad Discontinuity Sial Layer Sima Layer 11 Moho discontinuity 11
Earth Bottom The Seismology:-The Seismology is good method to know the consists of Earth Bottom. Moho (Yugoslavian Scientist) isthe first one who notice Difference in Earth Layers by using the Primary and Secondary Waves. The Waves behaviour are changed at depth about 35km, this means changes in properties of rocks Called Moho Discontinuity. Moho Discontinuity:-it is an imaginary limited zone separated between earth crust and mantle at depth between 35-50 km (depends on its position in different Continents). Earth Mantle The information about the mantle is get by geophysical methods, since the increasing of seismologic waves speed is leading to collection of Ferric-magnesium which is mean dark colour rocks. Mantle thickness is about 2650 km. Scientists are identified two Layers:- Upper Layer (Peridotite):-The Density is about 3.4 gm/cm3 consist of Basic or Ultra basic Igneous Rocks with more Dark Colure. Lower Layer (Pallasite):-It is consist of basic Minerals and Ferric Metals. Earth Core (Centro Sphere) The Thickness of Core is about 3600 km. The Core consist of Ferric about 90%, Nickel about 10%. Scientists collects information about the core of Earth by indirect methods by way of seismological waves and Meteor, meteorites analysis which are fall on Land from time to time. The analysis of Meteor and Meteorites shows Ferric, Nickel and some Chromium and Cobalt Metals Some Specialists divided Core of earth into:- 1- Outer Core (fusion). 2- Inner Core (Solid). 12
Earth Crust Consists The Oxygen percentage about 50% .It is not free, but chemically Combined with Another Elements to form element oxides. Since Si is at second order, the expectation SiO2is the most existence ,Then AlO, FeOCaO and so on. Usually more of Metallic oxide is combined with silicon oxide to form Silicate Materials like Potassium, Aluminium, Silicate(KAl2SiO8) and Magnesium, Silicate(MgSiO3).These minerals are Naturally Crystalline with out human made and named (Minerals). The Minerals are find in Nature as free or Minerals consist rocks. Minerals are creating from Atoms in Geometric Arrangement which is differentiate every one of Minerals. Average of Elements consists Earth Crust as Weight% are:- O=46.60 Si=27.7 A=l8.10 Fe=5.00 Ca=3.60 Na=2.80 K=2.60 Mg=2.10 Others=1.5 100% Uncrystalline or Glassy Materials without geometric arrangement are not minerals. Usually minerals are combined together forming Rocks. Some minerals are Native like Gold, Diamond, Silver, Sulphur, Cupper, Graphite and Platinum. Conclusion:- The earth crust is consist of:- 1-Crystals. 2- Minerals. 3- Rocks. 1- Crystal:-Crystal is Sold body, homogenous in chemical compound, particular by Crystalline Planes. The Minerals are creation Naturally in Earth Crust by way of (crystallization). Amorphous:- it is no crystalline minerals, unstable chemical compound , unstable crystalline building, without chemical Formula. 13
A - Faces C A B Closed Crystal Face Open Crystal Interfacial Angle B - Edges Angle C - Solid Angle Faces and angle of crystals Outer Properties Of Crystals The properties of Crystal are depend on:- 1-Crystal Faces:-The Crystals have regular outer planes named (Crystal Faces) A . 2- Crystal Angles:- a-The angle between two neighbor faces is named (Edge Angle) B . b-The angle between three neighbor faces is named (Solid Angle) C . c-The angle between two faces is (Interfacial Angle), It can measured by two perpendicular columns on neighbor and 0pp0site faces C . 3-Crystal Form:- It means groups of Crystals are similar in shape, Area and its Crystal situation. The Crystal can be form of one shape of faces named (Simple Form) or many shapes named (Compound Form). 14
Elements Of Symmetry 4-Crystal Symmetry:-It means many of Faces, Edges and Angles are arranged around An Axis. The Axis must be pass by Center of Crystal. This arrangements is called Crystal Symmetry. The Core of Symmetry is Repetition of this Faces, Edges and Angles many times according to constant Low. 1-Plane Of Symmetry 3-Center Of Symmetry 2-Axis Of Symmetry 4-InversionAxis Of Symmetry A-2 C A-1 A A C A-3 A-4 B B B B C A-7 A A A-5 A-6 C 1-Plane Of Symmetry:-Plane is divided the Crystal into equals half, each of half is mirror picture for other. This plane Is called Plane of Symmetry. Planes of symmetry in Sodium chloride Crystal (NaCl) 15
6-fold axis (Hexad) 2-fold axis (Diad) 4-fold axis (Tetrad) 3-fold axis (Triad) 3-Center Of Symmetry It is an imaginary, Central point into Crystal. The distance between faces , edges, and angles in certain side is equal to the other in opposite side. 4-Inversion Axis Of symmetry This element collects between rotation symmetry and Inversion through the center of crystal . If the crystal has double inversion at rotation axis, it needs crystal rotation for(180ْ )firstly, then inversion every face, edge, or surface in crystal through symmetry center until the crystal takes its situation in vacancy. This Axis is called (Two-fold inversion) or(2). So for (3) , (4) and (6). Extraction Elements of symmetry are:-1- Plane of symmetry. 2- Axis of symmetry. 3- Center of symmetry. 4- Inversion axis of symmetry. 2-AxisOf Symmetry Axis:-It is an imaginary line pass by crystal center, that is means, If the crystal is rotated around this line (360 degree), face, edge and any line will repeated twice or more. 16
Crystallographic Axes Crystallographic Axes are imaginary, three lines into Crystal, intersects at Crystal Center in point named (Axial Cross). c+ 1,2,3-Axial Angles a- 2 1 1= α Angle 2=β Angle 3 =γ Angle b+ b- a+ 3 Axial Cross c- Crystal Systems:-The Crystals are divided into two classes:- A- Depend on the Axis lengths of Crystal and the Axial Angles between (α, β, γ ). B- Depend on the grad of Symmetry elements in the Crystal. On the basis of (A and B) above, the Crystal systems divided into (seven-7) systems:- 1- Cubic System. 2-Tetragonal System. 3-Hexagonal System. 4-Trigonal System. 5-Orthorhombic System. 6-Monoclinic System. 7-Triclinic system. 17
cَ A = b ≠ c b 90ْ o a 90ْ c Construction Unit Zircon Crystal Mineral Crystals are:-1-Zircon-ZrSiO4 2-Rutile-Tio2 3-Cassiterite- SnO4 Crystallographic Axis 2-Tetragonal System A-Crystallographic Axis:-Three axis (two are equals, perpendicular on each other, while the third is longer or shorter and perpendicular on the two equals Axis. B-Elements Symmetry:- 1-Axis of Symmetry= 5 Axis(1-Tetrad,4-Diad). 2-Planes of Symmetry= 5 3-Center of Symmetry=available. 18
bَ a Mineral Crystals are:- 1-Quartz- SiO2 2-Apatite-Ca5(PO4)3 (OH,F,Cl) 3-Nepheline-(Na3(Na,k)(Al4Si4)O16 4-Beryl a a=a=a≠b b a 4-Trigonal System The Trigonal system is like Hexagonal System except:- a-Three equal axis and fourth axis is longer or shorter. a-One Axis of Symmetry ( 1- Triad ). b-Non existence any horizontal planes of Symmetry. Mineral Crystals are:- 1-Calcite- CaCO3 2-Corundum-Al2O3 3-Hematite-Fe2O3 4- Dolomite- (CaMg)CO3 ْ 7-Axis 4 axis Construction unit 3-Hexagonal System A-Crystallographic Axis:-Four Axis (Three are equal, The Anglebetween each two equal Axis is 120ْ . Fourth axis is Longer or Shorter and perpendicular the plane of three equal Axis. B-Elements of Symmetry:- 1-Axis of Symmetry= 7Axis(1-Hexad, 6-Diad). 2-Plane of Symmetry= 7 3-Center of Symmetry= available 19
Mineral Crystals are:- 1-Topaz-Al2(SiO4)(OH,F)2 2-Anhydrite-CaSO4 3-Sulfur – S 4-Andalusite-Al2SiO5 5-Olivine- (FeMg)SiO4 6-Barite-BaSO4 a ≠ b ≠ c c a b Anhydrite Crystal Caso4 CrystallographicAxis Construction Unit Sulfur Crystal S 5- Orthorhombic System A-Crystallographic Axis:- B-Elements of Symmetry:- 1- Three unequal Axis. 1- Axis of Symmetry = 3 (Diad). 2- The Axis are perpendicular 2- Planes of Symmetry = 3 each other. 3- Center of Symmetry=available. 20
6-Monoclinic System c Oblique Angle A ≠ b≠ c b Minerals Crystals are:- 1-Albite - NaAlSi3O8 6-Anorthite-CaAl2Si2O8 Plagioclase:-(2-Oligoclase) (3-Andesene) (4-Labrodorite) (5-Bitonite) a 7-Triclinic System A-Crystallographic Axis B- Element of Symmetry:- 1-Three unequal axis. 1-Axis of symmetry =absent 2-Unperpendicular axis. 2-Plane of symmetry =absent 3-Center of symmetry = available 21
The Minerals Minerals:-It is natural substance, solid, homogenous with systematic atomic building with particular chemical compound. Minerals creation:-There are different sources and manner of minerals creation. The minerals study is important to understand minerals accumulation, economic metals and ores deposits. Minerals creation is divided into three sources:- 1- minerals creation of magma:- 1- Magma:-It is Fusion Rocks, Viscose, Dense, High Temperature for degree It is allow to Movement of Elements consist it. Magma is available sub earth crust. But when Magma is moving up at Earth Surface through cracks, Fishers or Volcanic activities, its fusion of Rocky is called - Lava Most Minerals consist Earth crust are result of Magma or Lava Hardening. The eight(8) Elements ( O, Si, Al, Fe, Mg, Ca, Na, k ) are compose about 99% of Magma. While Volatiles Materials (Wat Vap, CO2, Cl, F, S etc) are compose 1% . 1-Magma Hardening is start with:-A- Silicates Minerals. B- Oxides Minerals.C-Sulfides Minerals. A- Silicate Minerals:-1- Plagioclase (Na, Ca)AlS3iO8 2-Olivine (Fe, Mg)SiO4 3- Pyroxene(Ca, Al, Fe, Mg)Si2O6 4-Amphibole(Ca ,Al, Fe, Mg)Si8O22 5-Mica K,Al,Fe,Mg)(Si4O10)(OH) 6-Orthoclase KAlSi3O8 7-Quartz SiO2 B- Oxide Minerals:-1-Magnetite Fe3O4 2-Chromite FeCr2O4 3-Hematite Fe2O3 4-Quartz SiO2 C- Sulfide Minerals:-1-Galena PbS 2-Pyrite FeS2 3-Chalcppyrite CuFeS2 42 22
2- Exchange Reaction Between Solutions:-Sometimes Two solutions to be opposite , So reaction together, resulting specialist Minerals:- CaSO4+BaCO3 CaCO3(Calcite) + BaSO4 (Barite) Crystalline Minerals (Evaporative Salts) 3-Creatures Affected On Solutions:-Some Animals and Plants in Seas Extracts certain dissolved Ions to Build their Skeleton, Bone, Shell :- a-Coral-Extracts CaCO3-Building Oyster, Sponges, Shells. b- Foraminifera - Extracts Si –Shell Building. c- Bacteria – Absorbed Fe and S oxides. All these Creations after Dead may be consist a create quantities of detriatal sediments in Sea Floor. Solubility Product B-Under ground Solutions The underground Solutions divided into:- 1-Hydrothermal Solutions:-This Solutions are remaining of Magma Crystallization, very hot, high pressure and saturated with dissolved Oxides, Sulfides, Carbonate and so on. It is moving up faraway from its source through deep zones of Earth crust. During that It loss the temperature and pressure gradually resulting hydrothermal Deposits which are divided into three type depend on Temperature and Pressure. a-Hypothermal Deposits:-500 - 300 C High pressure(deep zone) example -Wolframite (Fe,Mn)WO4 -Molybdenite MoS2 -Cassiterite SnO2 b-Mesothermal Deposits :-300 – 200 C Medium Pressure (Medium zone) example -Calcite CaCO3 -Barite BaSO4 -Galena PbS -Sphalerite ZnS C-Epithermal Deposits:-50 – 0 C Low Pressure (shallow zone) example -Quartz SiO2 -Calcite CaCO3 -Stibnite SbS2 -Opal Sio2 -Cinnabar HgS Flourite CaF2 Marcasite fes2 2-Minerals creation of solutions:-Solutions divided into:-A-Surface solutions. B-Underground Solutions. A- Surface Solution:-Oceans, Seas, (Saline Water) Lakes, and Rivers. 1- Evaporation of Solutions (High T) = Crystalline Minerals. (Depend on Solubility Product of Ions which is consist Minerals). CaCO3 MgCO3 K2CO3 Na2CO3 CaSO4 MgSO4 k2SO4 Na2SO4 CaCl2 MgCl2 KCl NaCl 23
Mountain Travertine CaCO3 WaterTable Stalactite Stalagmite Hot Spring Cave Aquifer 2-Evaporation of Assistant Dissolved Gas Underground Solutions contains dissolved CO2 Gas as a result of Rainfall. This is result H2CO3 (weak Carbonic Acid), Which is dissolved Limestone and to form Calcium Bicarbonate Ca (HCO3)2.The later is Chemically unstable. So It is escape CO2 Gas and come back to Calcium Carbonate. CaCO3+H2O+CO2 Ca(HCO3)2(Deposited Calcium Bicarbonate) (1) Ca(HCO3)2 CO2+H2O+CaCO3 (Deposited Calcite) (2) This phenomena is clear in Rainy, Cavities and Limestone Regions, Since Limestone is Deposit inConical Shapeas above Equation, Named:- Stalactite and Stalagmite. 24 Hot Body 24
3-Minerals Creation of Gases After Minerals Crystallization of Magma and Minerals Deposition of Hydrothermal Solutions, The remaining Solution ( 1% 0f Magma) becomes enrichment with Volatiles and Gases ( Water Vapor, Cl, CO2, F, S, B ) The later try to escape from Magma under suitable conditions like Pressure decreasing through Joints, Faults and rock pores. The Volatiles and Gases may be Reacted together or with surrounding different Rocks to form a new Minerals NEW MINERALS:- Volatile Compound) SnF2 + 2H2O (Cassiterite) SnO2 + 4HF Some times, Limestone affected by Hydrofluoric Acid (HF) 4HF + 2CaCO3 (Fluorite)2CaF2 + 2H2O + 2CO2 Another Minerals:- Tourmaline (Sl,B,Al,Fe,Mg,Na,O) Solution Rich Boron TopazAl2(SiO4)C(F, OH)2 Solution Rich Floured When the Gases are near Earth Surface, they are try to escape through Volcanic Activities to form Sulfur S, Halite NaCl etc 25
26 26
1- Optical Properties A-Color:-It is the first physical properties which is noticed in the Field, so it can be divided into. 1-Constant Colors:-Gold and Sulfur(Metallic yellow), Malachite (Green) Cinnabar(Red). 2-Variable Colors:- Pure Quartz(Transparent), Impure Quartz(Rose, Smoky). B-Play of Colors:-Some Minerals have different Colors through rotated it, because of light scattering, So Diamond is Good example. Another Mineral show Silky Waves with rotation like Satin spar(one type of Gypsum). C-Luminescence:-Some Minerals gives Light Radiation when it subject to Heat, X rays, Ultraviolent Rays, Fraction and Electrical Energy. The light Radiation Color is different of the Mineral Color. When Radiation disappears with affected stopping the phenomena is called (Fluorescence) Which is derive from Fluorite Minerals (CaF2). If Radiation Color stays during affected stopping, Phenomena is called (Phosphorescence). D-Streak:-It is Mineral Powder resulting from fraction on Streak Plane. Many Minerals have Streak Color different of Original Color, Such as Pyrite(FeS2) is Yellow, while its Streak is Black. Chromite Mineral is Black Color, While the Streak is Brown color. E-Transparency:-It is depend on mineral ability to pass light such as:-. 1-Galena, Gold, Pyrite are Opaque Minerals. 2-Pure Quartz, calcite, Gypsum layers are Semi Transparence. 3-Pure Muscovite is Transparence. F-Luster:-This optical property depends on amount and kind of reflected light on Minerals.1-Metalicluster--Gold , Silver , Galena , Pyrite. 2-Nonmetalic Luster:- 1-GlassyLuster – Likes normal Glass. 2-Adamantine– likes Diamond luster. 3-PearlyLuster, like Pearl luster – Talc and Mica minerals. 4-SilkyLuster, One of Gypsum Kinds. 5-Earthy Luster, Likes Clay minerals Kaolin. G-Tarnish:-Some minerals have different COLORSon mineral surface, as a result of outer layer analysissuch as, Cupper, Bornite minerals. Notice:-In tarnish case the original color is found only at new broken of mineral surface. A-Physical Properties of Minerals It Means the Natural Properties of Minerals which is divided into:- 1-0ptical Properties:-Include Properties depend on Light such as Color, Play of Colors, Luminescence, Streak, Transparency, Luster, Tarnish. 2-Cohesive Properties:-Depend on Cohesion and Strength of Minerals such as Hardness, Cleavage, Parting and Fracture. 3-Electrical and Magnetic Properties:-Like Pyroelectricity, Piezoelectricity, Paramagnetic, Diamagnetic. 4-Specefic Gravity. 5-Thermal Properties:- Like Fusion Degree. 6-Sense properties:- Depend on Senses like Taste, Perfume and Contact. 27
B-Cleavage:-Many Minerals are easy cleave in systematic directions named (cleavage Planes) the Later is always parallel to Mineral Crystal face at weak point. C-Parting:-Likes Cleavage but it is in depend on Mineral Crystal Face or Weak point, So it is a result of outer Natural factors after Minerals Consisting like Pressure and Tension. D-Fracture:-It is a Mineral Surface Shape which is result of mineral broken at non cleavage Plane. So there are many types of Fracture Planes like Conchoidal, Flat,Unflat, Toothed, Earthy. 2-Cohesive The Cohesive Properties areDepend On Cohesion and Mineral Elasticity, Which is result of Ionic arrangement Strength. It is divided into:- A-Hardness:-It is a degree of Mineral Resistance for Scratch, Scrape, fragment and Corrosion.Mohُs Scale of Hardness 1-Talc Al4(Si8O20)(OH)4 Human skin 2-Gypsum CaSO4 2(H2O) 3-Calcite CaCO3 Finger nail 4-Flourite CaF2 5-Apatite Ca5(Po3)4(OH,F,Cl) Kitchen knife 6-Orthoclase KAlSi3O8 Window Glass 7-Quartz SiO2 8-Topaz Al2(SiO4)C(F,OH)2 Steel File 9-Corundum Al2O3 (Yakut in Arabic) 10-Diamond C 28
B-Magnetic Properties Some Mineralshave ability to pull a magnet while another's are Repulsive a Magnet. A- Paramagnetic Minerals:-It is the Minerals which are Pull or Attractive Magnet like Magnetite (Fe3O4) – Hematite (Fe2O3) B-Diamagnetic Minerals:-It is the Minerals which are Repulsive a Magnet like Quartz (SiO2) – Calcite(CaCO3) – Zircon(ZrSiO4) . These Properties are used in Geophysical Explorations for some Metallic Ore Deposits like Fe, Ni Ores. 4-Specific Gravity:- Mineral Weight in Air Specific Gravity=X Solution Density Mineral Weight in Air – Mineral Weight in Solution Specific Gravity is constant for the minerals at constant temperature and chemical condition. . 3-Electrical and Magnetic Properties A- Electrical properties:-1- Some minerals aregood electricconductorlike Graphite(C), some of oxides minerals (Hematite - Fe2O3) and Sulfide Minerals (Galena– PbS). 2-Most Minerals arebad or Non Electric Conductor. 3-Some Mineralsbecomes charged with Electricity in case of Heating. This phenomena called (Pyroelectricity). TourmalineMineral is good example which is use in temperature Measurement result from Bombs Explosion. 4-Quartz Mineral ischarged with Electricity under direct Pressure (Piezoelectricity). It is useful phenomena for Industry of Radio and wireless Instruments. 29
B-Chemical properties of Minerals The Minerals are Consist of (Major Elements – High Percentage) and (Trace Elements – Very Low Percentage). The Detection of Minerals Composition are by Methods of:- A-Qualitative Method:-It is Quick method to detects major elements by Flame Color which is reflect Element Type. B- Quantitative Method:-It Means Detection the Percentage of Elements which are Consist Minerals by many Physical and Chemical methods:- 1-Chemical Methods:- a-Volumetric Method. b-Gravimetric Method. 2-Phsical Methods:- a-Spectrographic Method. b-X – Ray Fluorescence. c-Electron Microprobe. 5- Thermal Properties:-Fusionis The Important Property to identified Minerals Which have different Fusion Temperature as:- (Stepenite - 525C) (Halite – 800C) (Silver – 960C) (Gold – 1062C) (Quartz – 1650 1700C) (Platinum – 1755C). Some Minerals change directly to Gas with out pass in Fusion state like Arsenic 6-Sense Properties:-This Property is depend on Many Senses like Feel or Tough, Taste and Perfume as:- 1-Talc Mineral Al4(Si8O20)(OH)4 Fatty or Soapy Tough. 2-Halite Mineral NaCl Salty Taste. 3-Pyrite Mineral FeS2 With Heating – Sulfur perfume. 30
Crystal Chemistry of Minerals It is depend on relationship between chemical composition and atomic building for mineral. The crystal chemistry science is divided into:- 1-Co – Ordination Number.2-Chemical Bonds. 3-Polymorphism. 4-Isomorphism. 5-Pseudomorphism. The First and Second Properties (1 – 2) are study at Inorganic Physical Chemistry while others ( 3 – 4 - 5 ) are Explain now:- 3-Polymorphism:-It Means More of one Crystal Shape are Crystallized from Same Substance, such as Diamond and Graphite are Consist of Carbone ( C ) but Diamond is Crystallized in Cubic System, While Graphite is Crystallized in Hexagonal System, So there are difference in all Physical Properties like Colors , Hardness and Specific Gravity. Calcite and Aragonite are Consist of CaCO3 (Calcite (Trigonal) (Aragonite – Orthorhombic). Quartz and Tredemiteare consist of SiO2 (Quartz – Trigonal), (Tredemite – Orthorhombic). Note:-Two Minerals are Similar named Dimorphism, Three Are Trimorphism etc. B-Chemical properties of Minerals The Minerals are Consist of (Major Elements – High Percentage) and (Trace Elements – Very Low Percentage). The Detection of Minerals Composition are by Methods of:- A-Qualitative Method:-It is Quick method to detects major elements by Flame Color which is reflect Element Type. B- Quantitative Method:-It Means detection the percentage of elements which are consist minerals by many physical and chemical methods:- 1-Chemical Methods:- a -Volumetric Method. b-Gravimetric Method. 2-Phsical Methods:- a-Spectrographic Method. b-X – Ray Fluorescence. c-Electron Microprobe. 31
NaAlSi3O8 CaAl2SI2O8 Classification of Minerals:-There are many kinds of Classification:- A-Economic Classification :-It depend on Economic Value of Mineral like Diamond, Gold, Platinum and Silver, Cupper and Lead, Zinc. B-Crystal Chemistry:-like Chemical Bonds, Co-Ordination Number and Isomorphism. C-Similar Basic Ions:-Depend on Basic Ions Consist Minerals such as:- 1-Minerals Group contains Iron (Fe):- (Hematite-Fe2O3) (Magnetite Fe3O4) (Pyrite-FeS2) (Limonite-FeO(OH)nH2O. 2-Minerals Group contains Cupper (Cu):- (Chalcopyrite-CuFeS2) (Borenite- Cu5FeS4) (Anargite-Cu3AsS4) (Chalcosite Cu2S). 3-Minerals Group contain Lead (Pb):- (Galena-PbS) 4- The bestClassification for Minerals is depend on (Kind of Acidic Ions) of J.D.Dana an American Scientist, So Minerals are Classify into Oxides, Sulphates, carbonates, Phosphates etc. Note:-More than 2000 Minerals are Known yet. 4-Isomorphism:-It means two minerals are different in chemical composition and similar in crystal shape. It is series of minerals which is create through replacement between two atoms almost are equals radius like sodium (Na) and calcium (Ca) to consist a Plagioclase Series. It Crystallized in Triclinic system. Plagioclase Series is different in chemical composition, So it has graduation of physical properties at two end sides. 5-Pseudomorphism:- It means mineral has constant atomic building and chemical composition while its outer shape like another mineral such as Pyrite(FeS2) may be change to the Gothite Mineral(FeO2) but the later is still has the same outer shape of Pyrite. 32
5-Carbonate Minerals Group:- Calcite CaCO3 Dolomite CaMg(CO3) Aragonite CaCO3 Magnesite MgCO3 Weatherite BaCO3 6-Sulphate Minerals Group:-a- Anhydrous:- Anhydrite CaSO4 Barite BaSO4 Selestite SrSO4 . b-Hydrous:- Gypsum CaSO42H2O Malanterite FeSO47H2O . 7-Phosphate Minerals Group:-Apatite Ca5(F,Cl,OH)(PO4)3 . Monosite (Ce,La,Th)PO4 Vanadenite Pb5Cl(AsVO4)3 . 8-Silicat Minerals Group:-It is the Biggest Group (consists about 90% of Earth Crust). Olivine (Fe,Mg) SiO2Hemomorphite Zn4(Si2O7)(OH)2.H2O Wilstonite CaSiO3 Beryl Be3AlSi6O18 Anstatite Mg2Si2O6 Tromolite Ca2Mg3Si8O22(OH)2 Muscovite KAl2(AlSi2O10)(OH)2 Clay Minerals (about – 120 Minerals) Talc (Si4O10)(OH)2 Quartz SiO2 Orthoclase KAlSi3O8 Plagioclase (Na,Ca)Al2Si3O8 J.D.Dana Classification of Minerals 1-Native Elements (Minerals) Group:-a-Metallic Minerals:- Gold Au Platinum Pt Cupper Cu Silver Ag. b-Semi Metallic Minerals:- Bismuth Bi Arsenic As c-Nonmetallic Minerals:- Diamond C Graphite C Sulfur S . 2-Sulfide Minerals Group:- Galena PbS Pyrite FeS2 Chalcopyrite CuFeS Sphalerite ZnS Marcasite FeS2 Arsenopyrite FeAsS Mobidnite MoS2 . 3-Oxides and Hydroxides Minerals Group:-a-Oxides (Anhydrous):- Corundum Al2O3 Hematite Fe2O3 MagnetiteFe3O4 b-Oxides (Hydrous):- Limonite FeO.OH.nH2O Opal SiO2.nH2O . b-Hydroxides:- Gibbsite Al(OH)2 Brosite Mg(OH)2 . 4- Halides Minerals Group:-Halite NaCl Fluorite CaF2 Atacamite Cu2(OH)8. 33
Lithification Sediments Sedimentary Rocks Transportation Weathering-Erosion Metamorphism Igneous Rocks Metamorphic Rocks Rocks Cycle Crystallization Fusion Magma ROCKS Rocks:-It is a Solid substance Consist of one Mineral or Mixture of Minerals. Earth crust is Consist of:-1-Igneous Rocks.2-Sedimentary Rocks.3-Metamorphic Rocks. 34
1-Igneous Rocks It is create by Rocky Melting Harding with high temperature.(It named Primary Rocksbecause of all the Rocks are derive from it). -Magma:-When Harding is below earth surface. -Lava:-When Harding is over earth surface. A-Properties of Igneous Rocks:- 1-In general it is crystalline rocks. 2-It is not contain Fossils. 3-No indication of strata shape. B-Chemical and Mineral Composition of Igneous Rocks OxidesPercentage% 1-Sio240-75 2-Al2O3 10-20 3-FeO 1-10 4-Fe2O3 1-10 5-MgO 1-10 6-CaO 1-10 7-K2O 1-6 8-Na2O 1-6 1- The right part of a side figure( 1 )is show Rocks Rich in Si,Al,Na,K which means Rocks contains (Orthoclase KAlSi3O8), (Plagioclase rich in sodium NaAlSi3O8) with little of Ca Plagioclase named (Acidic Rocks) which are light color and low density. The excess of SiO2 is forming Quartz (with very little of ferromagnesium minerals). 2-The Rocks at Wright figure( 2 ) are rich In Ca,Mg, and Fe but they are poor in K,Na and relatively in Si, So this means rocks contains (Plagioclase rich in calcium CaAl2Si2O8), (ferro magnesium minerals, olivine (Fe, Mg)2SiO4 , Pyroxene group like Augite(Ca(Mg,Fe,Al)AlSi2O6) No Quartz. This rocks named (Basic Rocks) which are blackish color and high density. 3- zone between 1and 2 are (Inter mediate Rocks) which are represent mixed of 1 and 2 Rocks. 4-Ultrabasic Rocks. 4 2 3 1 16 12 8 4 Al2O3 CaO Na2O FeO+Fe2O3 Oxides MgO K2O 50 55 60 65 70 SiO2 C-Melt Crystallization:-There are relationship between SiO2% and other oxides:- Increasing of Na2O and K2O increasing SiO2 Decreasing of CaO, MgO and FeO No relationship with Al2O3 35
M a g m a Discontinue Series Continue Series Temperature Decreasing First Crystalline Minerals Effect of physical factors on Magma Crystallization The Scientist N.L Bowenwasexplained The Crystallization of Minerals from Magma according to a certain sequence as:- Plagioclase Rich in Ca Olivine (Fw,Mg)Sio2 Pyroxene (Augite) (Ca(Mg,Fe,Al)AlSi2O6) Hornblende (Ca,Mg,Fe,Al)(OH)2 ((Si,Al)4 O11) Plagioclase Rich in Na Biotite (Mg,Fe)(OH)2(AlSi3O10 Orthoclase (KAlSi3O8) Muscovite K2Al4(Si6Al2O2)(OH,F)4 Quartz SiO2 Olivinein non continue series is unstable, that when the condition of olivine is change like temperature decreasing, pyroxene is start crystalline as a result of reaction between olivine and magma and Hornblende to biotite. Anorthitein continue series is start to change by replacement of Na in place of Ca (with replacement of Si in place of Al ) to form Plagioclase rich in Na instead of Plagioclase rich in Ca which results two kinds of rocks from (parent Magma) by way of (Differentiation):- A-acidic Rocks. B- Basic Rocks. 36
Ultra basic Rocks Basic Rocks Blackish Color-Light Density Acidic Rocks Light Color-Low Density Intermediate Rocks Obsidian Glassy Texture Fine Grains Texture Rhyolite Basalt Andesite Dacite Coarse Grains Texture Diorite Granodiorite Granite Gabbro 100% O r t h o c l a s e P l a g I o c l a s e (KAlSi3O8) (Na,Ca)AlSi3O8) Q u a r t z (SiO2) 50% Olivine Pyroxene Ferromagnesium Minerals Amphibole Biotite Mica 0% D-Classification of Igneous Rocks Porphyritic texture:-Coarse and fine crystals in the same rocks. Pumice:-Classy texture with fine spaces as a result of gas escape. 37
Igneous Rocks Existence in Earth Crust 1-Plutonic Rocks:-It is Exist in Deep regions of Earth Crust, So it is reflect slow cooling and stable Pressure, Which is result big, equal and good arrangement crystals (Coarse Grains Texture), Such as Granite, Diorite and Gabbro. This Rocks are Present in Earth Crust as very large Masses called (Batholith). These Masses consist Parts of Rocky and Alep Mountains for Hundreds kilometers Long, Tens kilometers Width and Unknown Depth. 2-Hypabyssal Rocks:-It is Exist in intermediate Deep Regions of Earth Crust, As a result of Magma Intrusive through Earth Layers. The Texture of these Rocks is Fine to Moderate like Rhyolite, Dacite, Andesite and Basalt. Hypabyssal Rocks are present in Dikes shape (Mass of Igneous Rocks are result of Magma up lifting through, vertical or oblique Fissures and Cracks). Thickness of Dikes are many centimeters' to Tens meters . Or asSillShape (Parallel to Layers). So it is Exist as a Small Dome named (Lacolith) with Diameter about Many Meters to Many kilometers, While Reverse Dome is Named (Lapolith) and Arciform Saddle Shape Named (Phocolith). 3-Volcanic Rocks:-Igneous Rocks are Hardening on Earth Surface, As a result to flow of Lava through Volcanic Activity or through Cracks and Joints. The Texture of Volcanic Rocks are Glassy or Microscopic Crystalsbecause of Sudden Cooling of Magna. Note:-a-Rocks contains Fine and Coarse Grains are Named Porphyritic Texture. b-Pumice is Volcanic Rock with Fine Spaces as a result of Gas Escape. 38
Shapes of Igneous Masses Volcano Sill Dike Phacolith Lacolith Lapolith B a t h o l i t h 39 39
2-Sedimentary Rocks Sedimentary Rocks:-It isCovers about 3 / 4 of Earth Crust. The last quarter is cover by igneous and metamorphic rocks. It is represented by:- 1- Sedimentary Rocks are represent by stratification (Many Layers) , Which reflect color, Thickness and minerals for each layer. 2-It is contain fossils (remaining of creatures). 3-Some Times it is Compose of particular Minerals like Halite (NaCl), Coal (C), Phosphates(PO4) and Petroleum. A- Sedimentary Processes:-Four Processes are lead to creation of Sedimentary Rocks:- 1-Weathering. 2-Transportation. 3-Deposition. 4-Diagenesis. 1- Weathering:-a- Wind. b- Water (Fresh, Saline). C-Glacial. d-Creatures. 2- Transportation:-The products of Weathering are Transport far away to Deposition Regions. The Transportation take place by:- a-River Water. b- Wind. c-Glacial. The Transportation is stay continuous with stability of Transportation condition such as wind and river velocity. 3-Deposition:-The Transportated Materials are Deposit by either:- a- Mechanical Deposition:-It is a result of changing for some mechanical agents like decrease of wind, current velocity, which result Clastics orMechanical Depositssuch as gravel, sand siltand clay. b-Chemical Deposition:-Some of transported materials are deposit in liquid or colloidal state by many chemical methods. So the Deposition may be result of reaction between different transported solutions such as:- 1- Transported Solutions. Na2CO3 + CaCl2 CaCO3 + 2NaCl 2-Transported Solutions with Gas. 2Fe+2 + 1/2O2 + 2H2O Fe2O3 + 4H+ 3-Gas Escape of Solutions. Ca(HCO3)2 CaCO3 + H2O + CO2 All these Deposits are calledChemical Deposits or Non Clastics Deposits.Like limestone, dolomite, gypsum and halite. c-Organic Deposition:- Some creatures are build their bodies of dissolved or colloidal which presents in water, So after death , These creatures are buried as Organic Deposits such as:- 1-Calcite (Oysters and corals are build their bodies of CaCO3). (Organic Calcite Rock). 2-Chert (Quartz is fine crystals). 3-Coal ( Remaining of vegetable with heat and pressure). 4-IronandSulfur (Bacteria is play as assistant agent in deposition of some ores). 40
2-Continental Deposits:-Continental deposits are include all the sediments of, wind, rivers, lakes and glaciers:-41 a- Wind Deposits:-1- Sand Dunes:- It is a result of weakness in wind power. 2- Talus Deposits:- It is accumulation of rock fragments at edges of highland and mountains. b- River Deposits:-1- Riverbed deposits:- Gravel, sand and clay as a result of reducing at river velocity. 2- Flood Plains Deposits:- Like flood plain of Djilas and Forat river and delta (Delta of neel river). They are consist of gravel, sand and Clay. c- Lakes Deposits:-1-Fresh lakes deposits:- Like river de41posits. 2- Saline Lakes Deposits:- As a result of evaporation of lake water , different salts of chemical deposits are forming. d-Glaciers deposit:-Different large and small materials (Loading Deposits) are present in frozen river (Glaciers) with very slow motion. When glaciers are dissolving, suddenly loading deposits are forming. Pressure Growth Replacement B-location of Deposition:-Deposition is either on continent, named Continental Deposits or in the marines, named Marine Deposits. 1- Marine Deposits: Most of marine sediments are carry by rivers (millions tens of sediments yearly) The size of these sediments are between Boulders deposits (64 – 256 mm) to Silt deposits(1 / 16 – 1 / 256mm). The factor control deposition processes is (Sorting Power) which is present in migration water. The Sorting Power plays important role in the sediment distribution so that the big sediments are first deposit, Then the smallest and smallest. Marine sediments divided into two kinds depend on site of these sediments:- a- Littoral(Tidal zone):- This zone is controlled by action of sea waves and tide. The sediments is:- boulders, pebbles and coarse sand. b- Neritic(Shallow-water zone) :-This zone is to extend off shore about 200 M depth. The sediments is:- Small gravel, sands and silt. 2-Continental Deposits:-Continental deposits are include all the sediments of, wind, rivers, lakes and glaciers:- a- Wind Deposits:-1- Sand Dunes:- It is a result of weakness in wind power. 2- Talus Deposits:- It is accumulation of rock fragments at edges of highland and mountains. b- River Deposits:-1- Riverbed deposits:- Gravel, sand and clay as a result of reducing at river velocity. 2- Flood Plains Deposits:- Like flood plain of Djilas and Forat river and delta (Delta of neel river). They are consist of gravel, sand and Clay. c- Lakes Deposits:-1-Fresh lakes deposits:- Like river deposits. 2- Saline Lakes Deposits:- As a result of evaporation of lake water , different salts of chemical deposits are forming. d-Glaciers deposit:-Different large and small materials (Loading Deposits) are present in frozen river (Glaciers) with very slow motion. When glaciers are dissolving, suddenly loading deposits are forming. 4-Diagenesis:-It is all processes which affects in sediments through and after deposition but before hardening under normal conditions, Which leads to change in Texture and Minerals Consists as:- a- Cementation:-By cohesive materials likesand grains:- sand(SiO2)+ calcite (Caco3 ) or FeO sand stone. b-Compaction:-Here sediments are subject to Pressure like:- Clay Sediments Shale Stone c-Recrystallization:-Growth of fine grains to coarse grains without changing in chemical components like:- Lime Sediments coarse limestone d-Replacement:-It means replacement of Ion instead of other like:-Mg CaCO3 (Ca,Mg)CO3 Dolostone. e-Dissolving:-Rainfall (H2O) + CO2 H2CO3 H2CO3 + CaCO3 Ca(HCO3)2 41
Clastics (Mechanical) Of Sedimentary Rocks 1-Boulders > 256mm 2-Gravels 256 – 2mm 3-Sand 2 – 1 /16mm 4-Silt 1 /16 – 1 / 256 5-Clay < 256mm D-Primary Structure Of Sedimentary Rocks The primary structureof sedimentary rocks are forming through Sedimentation Processes, As a result of natural conditions which are control rocks forming. There is difference between primary structures and secondary structures, That the later are formed by different forces after the deposition of sedimentary rocks like folds, joints and faults. There are many kinds of primary structures such as:- 1-Stratification:-Sedimentary rocks consist of sequence layers, So every layer has :- a- Thickness:- (Many centimeter is named Lamina – Many or hundreds meter is named Layer).Layer thickness isdepend onvolume, nature of sediments and sedimentation environment. Some times sedimentary body is deposited as lens, tongue. b- Bedding Planes:- (Two parallel planes are on and under the layer). 2-False or Cross Bedding:- One layer is consist of Many Lamina with different dip, As a result of changing in the strength of Current , Wind direction, which is reflect the original environment at sedimentation time. 3-Ripple Marks:-It is clear at recent sediments of beach , asa result of wave Current and sand flats of desert. 4-Mud Cracks:-Mud is loss water by sun heat, Which is lead to shrink, and to crack of mud in hexagonal sides shapes. Sometimes cracks are fill with sand or limestone deposit, So the later may be work cementing material. This criteria is useful to know ancient environment. C-Texture of Sedimentary Rocks Sediments and sedimentary rocks are consist of unitsnamed fragment grains or crystals. The description of these units called Texture. Description is include:-1-Surface Feature of Grains:-Some grains are Shiningand smooth, but another appears Scoreand pits. 2-Shape Of Grains:-It is Depend on roundness and sphericity.Some grains are angular, While anthers are without angle, So between these two kinds all the grains are present. For the Sphericity the Grains may be as Cylindrical Sphericity, Tablet Sphericity and Razor Shape. 3- Grains Size:-Many Scales are Known such as:-1-The sediment is called Sorted when all grains are equal. 2-The sediment is called Badly Sorted when grains are between large and small. 42
E-Classification Of Sedimentary Rocks Chemical And Organic Sedimentary Rocks Mechanical Or Clastic Sedimentary Rocks Chemical Coal Forming Stages :- Plants Remaining in Swamps for a long TimeBeatLignite AnthraciteBituminous Bury Heat and Pressure More Heat and Pressure For a Longer Time Heat and Pressure for a Long Time 43 43
Metamorphic Rocks Metamorphism:- It is chemical, physical and mineralogical changes which is occur on original rocks. Igneous, Sedimentary and even metamorphic rocks). When these rocks are subjected to heating or pressure or both., The metamorphic rocks becomes stable under new conditions. All the metamorphism processes are happened in solid state with assistant of hydrothermal solutions which are present in Rock pores. Classification of Metamorphic Rocks Non Foliated Rocks Foliated Metamorphic Rocks Sedimentary Rocks Increasing at Temperature and Pressure 44
Dynamic Geology Geological observations shows very slow changes in the earth by comparative with human life, But we can notice this changes in different geological methods. The energy is responsible for all changes in earth. there are two source for energy:- A- Solar Energy (Outer Source):-It is the major source of energy on earth surface, Which is affected on atmosphere, hydrosphere and biosphere covers. The solar energy on oceans, seas and lakes leads to water evaporation, Then rains, Ice fall, flowage to the rivers, Then the sediment will be transported and deposited. The rivers and wind are transport weathered rocks to the sedimentary basins and seas as transported sediments. Also solar energy is the reason of bioactivity through plant cover, sea creatures. B-Earth Bottom (Inner Source):- Some scientists believes that, the source of heat which is drive convection current in mantle and core is both original heat from the planets formation and heat from the decay of radioactive isotopes. The position of these hot sources forms a hot zones leading to rise and down convection current, So the result is horizontal movements in the rock cover (Lithosphere), Which consist of many Plates float on the lower mantle (Asthenosphere). When two plates are moving toward each other it named (Convergent Plate Boundary) ,and two plates are moving a part, (Divergent Plate Boundary) and when two plates move horizontally parallel each other it named (Transform Plates Boundary). The Energy is play continues changing in Earth Crust through two kinds of processes:- 1-Epigene Processes. 2-Hypogene Processes. 1-Epigene Processes(External Processes):- It is a reaction result of all processes between atmosphere, hydrosphere and biosphere with earth crust. These processes leads to formation of earth shape by different topographic (relief) phenomenon by:- A-Weathering. B-Erosion. C-Transportation. D-Deposition. A- Weathering:- It is all the processes leads to disintegrate rocks into small parts. 1- Mechanical Weathering:-It meansDisintegrate of rocks with out changing in mineralogical composition. a- Change in Temperature:- Daily or seasonally change in temperature leads to expansion and shrinking (Contraction) of rocks, Which is leads to Rocks Exfoliation. b-Unloading:- It means removing of layers weight from one layer, which is result sheeting of layerswith some cracks, then easy to disintegrate. c-Bioactivity:- Roots of Plant between the rock cracks is lead to disintegrate of rocks. 45
2-Chemical Weathering:-It is true reaction between hydrosphere and atmosphere with lithosphere by assistance of mechanical weathering (heat, secretion of creatures). The chemical weathering means analysis of rocks to another minerals may be different of original minerals as :- a-Oxidation:- Most minerals consist rocks are contain Iron like pyroxene, olivine, So oxidation of these minerals leads to Iron oxide on their surface (Red or Black color). This phenomenon is clear at desert region and called (Desert Varnish) like:- FeS2 + 2O2 S + FeSO4 (Ferris Sulfate is well Dissolved in water. b-Carbonation:-It means reaction between CO2 (Atmosphere) with Rain Water to Consist H2CO3 as :- CO2 + 2H2O H2CO3 + H2O Carbonic Acid reacts with Rocks contain Alkaline (Oxides of Sodium, Potassium and Calcium). H2CO3 +CaCO3 Ca(HCO3) (Soluble in Water) This reaction leads to disintegrate of Bicarbonate Rocks to form Caves with beautiful Formation of Stalactite and Stalagmite. c- Hydration:-Union between Water and Some Minerals to form Hydrate Minerals. KAlSi3O8 + 2H2O + CO2 AlSi2O5 + 4SiO2 + KCO3 OrthoclaseKaolinite Sand The Reaction result is showResource of Kaolinite and Sand. Another Reaction between Anhydrite and Water:- CaSO4 + 2H2O CaSO4.2H2O Anhydrite Gypsum d-Dissolving and Organic Agents:- Some Minerals Dissolved in Surface or Ground Water, So water of Creature is increase Rocks Humidity, Thus all these agents leads to Disintegrate of Rocks 46
Chemical Weathering Chemical Weathering B-Erosion:-It is mean rocks disintegrate (Weathering), transportation of weathering products and Deposition of these weathered materials. Erosion is play either destructive or constructive agent……… How? Agents of Erosion :-1-Wind Action. 2-Surface Water Action 3-Seas Action.. 4-Glacierse Action. 1-Wind Action :It is depend on wind velocity. when the velocity at high speed, It is carry maximum load of weathered materials to different distance (Deflation) especially at dry Regions. here the wind action is Destructive, So by wind Abrasion. a- Destructive Wind Action:-Differential erosion in the soft and hard of sequence layers are forming many geomorphologic Phenomenon like:- 1- Mesa:-It is local platform surrounding by gentle slope figure1A . 2- Butte:-It is an isolated platform surrounding by step slope figure1B. 3- Mushroom:-It is an reverse half dome with neck figure I C . 4- Oasis:-It is a desert depression by wind action. Weathering Products and Soil Formation Mechanical and chemical weathering plays together to break and integrate all the rocks. The weathering products may be stay or transported to other region as:- 1- Mechanical Weathering is Dominant at Polar and Desert Region. 2- At moderate regions, chemical weathering is dominant at summer while mechanical weathering is dominant at winter. Example :- Granite is plutonic rock, It is Consist of ( Quartz + Orthoclase + Plagioclase + Little amount of Biotiteand Muscovite + Trace amount of Zircon and Apatite). a- Quartz, Biotite and Muscovite are Resistance Minerals. b- Orthoclase is analysis by (Carbonation or Hydration) into 1- Colloidal Silicate + Potassium Salt Dissolved in Water. 2- Remaining of Clay Minerals. c- Iron and Magnesium Minerals 1-Colloidal Silicate + Some of Iron and Magnesium dissolved in Water. 2-Remaining of Clay Minerals. Boulders and Soil are Weathering Products in very Large regions on Earth Surface. 47
Figure 1 Some of Geomorphologic Phenomenon by Wind Action C-Mushroom B-Butte A-Mesa 48 48
Wind direction at sand flats of desert Figure 2 A R i p p l e M a r k s Waves current direction at sea beach B-Constructive wind action:- Wind Action becomes constructive due to the losing of wind velocity. So the load of wind (different detrital Rocks) descend on the land to form either:- 1-Unsteable Phenomenon like Ripple Mark Figure 2 A . 2-Steable Phenomenon like Sand Dunes and Loss Deposits Figure 2 B. 49 49
Faster Wind Eddy Current Wind Direction Wind Wa rd Slope Lee Slope Slower Wind 30ْ 10ْ S a n d D u n e F o r m i n g Figure 2 B Sand Dunes Forming is a result of reducing at wind velocity. Sand dues are growth around small part (Gravel or Sand) called Nucleus. Some times it moves to another place with wind direction by way of Sand Dunes Migration. Dunes highest is between (few – many Tens) feet. Loess Deposits :- It is very fine grains (Dust) of quartz, mica, calcite and feldspar with reddish yellow, suspended in air for a long distance, Then it is descend on earth surface by gravity or rainfall. The typical formation is Loess Area in France. There are many kinds of Sand Dunes Figure 3 :- 50