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Altınbaş University

2024

Dr. Moheldeen A. Hejazi

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earth sciences geology plate tectonics earth science

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This document is a lecture on Earth Sciences for Civil Engineering. It covers various topics, including Earth's structure, processes, and hazards, along with the theory of plate tectonics. An important part of this lecture is the processes involved in formation of continents, mountains and plate tectonics in details.

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EARTH SCIENCES FOR CIVIL ENGINEERING LECTURE 2 DR. MOHELDEEN A. HEJAZI Dr. Moheldeen HEJAZI [email protected] 1 Earth Sciences: The study of the Earth and its systems Dr. Moheldeen HEJAZI 10/24/...

EARTH SCIENCES FOR CIVIL ENGINEERING LECTURE 2 DR. MOHELDEEN A. HEJAZI Dr. Moheldeen HEJAZI [email protected] 1 Earth Sciences: The study of the Earth and its systems Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Earth Sciences = Geology Earth Sciences Branches General geology Ore deposits-Geochemistry  Structural  Mineral deposits geology  Geochemistry  Sedimantology-Sedimentary petrography  Petroleum Geology  Stratigraphy Applied Geology Mineralogy-Petrography  Engineering Geology Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Mineralogy  Hidrogeology  Petrography  Mathematical Geology Earth Sciences: Processes, Potentials, and Hazards Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] How old is the world and theories on its creation? Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Layers of the earth Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] How continents are formed? Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] How the mountains are formed and eroded? Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Layers of EARTH Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Atmosphere Blanket of gases surrounding the Earth  Protection from Sun’s heat & UV rays  Weather: due to exchange of energy  between Earth’s surface & atmospher  between atmosph. & outer space  Strongly interacts water/ surface Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Hydrosphere Water portion of Earth  Oceans (most prominent) 71% of surface of Earth  Streams, lakes, glaciers, underground water  Atmosphere Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Cryosphere Icy portion of Earth’s crust  Glaciers  Permafrost and ground ice  Polar ice caps Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Frozen polar seas Biosphere Earth’s Ecosystems  Earth’s surface and subsurface to depths of a few kilometers  Life occupies an extreme range of environments Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Life strongly interacts with the atmosphere, the hydrosphere and the solid earth (these interactions are called ecology!) Earth’s internal structure 3 distinct divisions: Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] crust Oceanic 0-6 km (“young”, < 180 m.y.) Continental 0-34 km (older, up to 3.8 b.y. ) mantle Upper 34-670 km Lower 670-2900 km core Outer – Liquid Inner – Solid Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Earth’s internal structure Continental crust – Underlies the continents.  Avg. rock density about 2.7 g/cm3.  Avg. thickness 35-40 km.  Felsic composition. Avg. rock type = Granite Oceanic crust – Underlies the ocean basins. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Density about 3.0 g/cm3.  Avg. thickness 7-10 km.  Mafic composition  Avg. rock type =Basalt/Gabbro Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Crust ve Earth’s internal structure Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics Plate tectonics, theory dealing with the dynamics of Earth’s outer shell, the lithosphere, that revolutionized Earth sciences by providing a uniform context for understanding mountain-building processes, volcanoes, and earthquakes, as well as understanding the evolution of Earth’s surface and reconstructing its past continental and oceanic configurations. Describing in detail the processes that make up the Earth's fundamental surface features, «The definition of lithospheric separation of rigid plates moving on the asthenosphere» (Alfred Wegener 1915) forms the basis of the plate tectonics theory. Earth's Structure and Tectonics Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Theories of continental drift and plate tectonics Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics Data indicatesthat Plates seperate from each other Coastal forms and continents match each other Similarity of sediment deposits; The continuation of the vegetation and geological structure of Africa, India, Australia, Madagascar, South America which make up Gondwana, Similarity of mountain ranges; When the continents are brought side by side, the mountain lines form a single continuous mountain line in the same age and deformation style. The glaciation that began in Gondwana was also experienced at the same time (carboniferous) by parts seperated from Gondwana The remains of the reptile family which is impossible to swim the ocean were found only in South West Africa and Brazil Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Palaeomagnetism Propagation of the sea floor Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics : when converging Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Subduction event occurs  Colliding with Oceanic/oceanic or oceanic/continental plate generated a deep ocean trenches  Crust melting and magma genaration occur  Volcanism and volcanic island arcs occur, volcanic island arcs arranged like a barrier can form inner seas between continents and the oceans  Events of metamorphism occur  Two continental or continental and an oceanic plate collides to form a curved mountain line Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Plate tectonics: when diverging Events happening in places where plates are moving away from each other :  Mid-ocean ridge (2500 m high ridge in the Atlantic Ocean)  Volcanic islands  New crust formation  Basaltic lavas are solidified and added to the continental margins, The ocean floor expands and the continents move away from each other  Magma is emerged from the fractures genarated by divergent event and volcanic events ocur Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected]  Best example of that is Atlas Ocean Plate tectonics: when sliding/transforming Transform Plate Boundaries are locations where two plates slide past one another. The fracture zone that forms a transform plate boundary is known as a transform fault. Most transform faults are found in the ocean basin and connect offsets in the mid-ocean ridges. A smaller number connect mid-ocean ridges and subduction zones. The most famous example of this is the San Andreas Fault Zone of western North America. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Another example of a transform boundary on land is the Alpine Fault of New Zealand. Plate tectonics The most common areas of tectonic earthquakes in the world are: Great Oceanic boulders (Pacific waters): Kamchatka in the east of Asia, Japan, the Philippines, Indonesia, the Aleut Islands in the west of America, California, Mexico, Chile, Peru. Mediterranean Himalayan Belts: Spain, Italy, North Africa, Yugoslavia, Greece, Turkey, Iran, India, Pakistan, Afghanistan, East Indian islands. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Central part of Atlantic Ocean: Asor Islands and Iceland Island Plate tectonics The least common areas of tectonic earthquakes in the world are: The Western of Australian, The Eastern of USA and Canada Iceland of N.West European-Grönland, İskandinav peninsula, Eastern Europe Northern of Asia Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Sourthern and Middlest of Africa Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Geologic Time… Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Geologic Time… Washington May 17, 1980 September 10, 1980 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] EARTH CRUST Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Average depth of the earth crust thickness is 8-10 km. There are two different rocks which have different chemical and biological content. ▪ Sial; average density: 2.7 gr/cm2 (granite, sandstone and limestone) ▪ Sima; 2,8-3 gr/cm3 (bazalt type rocks) The sial layer in the ocean floor is almost absent. Sima reaches 8-10 km thickness. MATERIALS WHICH GENERATES THE CRUST Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Eight of the 108 elements found on the Earth's Oxygen %46.6 surface are very common. Silisium %27.72 The 8 most common elements in the crust form Aluminum %8.13 98.59% by weight of the ground shell. The remaining 98 elements constitute 1.4% by weight Iron %5 of the earth's crust. Calcium %3.63 Sodium %2.83 Potassium %2.59 Magnesium %2.09 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] MINERALS Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] It is found naturally Has chemical composition(element or compound form). It can be expressed by a specific crystal system. It is mostly solid, liquid (mercury and water) Generally inorganic, at least organic compounds. The Importance of Minerals Minerals and mines are part of the legacy that remains to us from the geological past. These are the basic building blocks of the solid part of the earth and are very important for construction geology; Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] The minerals and rocks are the main sources for the production of automobiles, computers and many other things we use, Minerals and rocks play an important role in many earth processes such as landslides, coastal erosion and volcanic activity, Studies on minerals and rocks provide important information on earth history, Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Knowing process properties of the minerals and rocks provides to how the mechanisms in the earth and to understand how we can best manage the our earth resources Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] CRYSTAL SHAPES OF MINERALS Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] PHYSICAL PROPERTIES OF MINERALS The main physical properties of minerals; ▪ Tenacity, ▪ Hardness, ▪ Fracture, ▪ Cleavage, ▪ Streak, ▪ Luster, ▪ Density Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Tenacity The property of tenacity describes the behavior of a mineral under deformation. It describes the physical reaction of a mineral to externally applied stresses such as crushing, cutting, bending, and striking forces. Adjectives used to characterize various types of mineral tenacity include 'brittle,' 'flexible,' 'elastic,' 'malleable,' 'ductile,' and 'sectile' Mica (turns back to its original state when twisted), Chlorite (remains twisted) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] When the hammer hit some minerals can become extended or plate. Gold, silver, copper. Tenacity Brittle - Breaks or powders easily. Malleable - can be hammered into thin sheets. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Sectile - can be cut into thin shavings with a knife. Ductile - bends easily and does not return to its original shape. Flexible - bends somewhat and does not return to its original shape. Elastic - bends but does return to its original shape. Tenacity Most mineral species are brittle, and will crumble or fracture under pressure or upon the application of a blow. Such materials break or powder easily. Antimony and quartz etc. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Hardness Hardness has traditionally been defined as the level of difficulty with which a smooth surface of a mineral specimen may be scratched. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] The hardness of a mineral species is dependent upon the strength of the bonds which compose its crystal structure. Hardness is a property characteristic to each mineral species and can be very useful in identification. Hardness Hardness minerals are resistance to scratching. It is the result of the cohesion between these molecules. It is determined with the aid Mohs hardness scale formed by mineral hardness. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Cleavage A cleavage plane is a plane of structural weakness along which a mineral is likely to split smoothly. Cleavage thus refers to the splitting of a crystal between two parallel atomic planes. Despite the fact that every mineral belongs to a specified crystal system, not every mineral exhibits cleavage. Cleavage planes, if they exist, are always parallel to a potential crystal face. However, such planes are not necessarily parallel to the faces which the crystal actually displays. Fluorite, for example, has octahedral cleavage yet forms cubic crystals. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Nonetheless, the property of cleavage, if it is present, can offer important information about the symmetry and inner structure of a crystal. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Fracture If the mineral contains no planes of weakness, it will break along random directions called fracture. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Several different kinds of fracture patterns are observed. Conchoidal fracture - breaks along smooth curved surfaces. Fibrous and splintery - similar to the way wood breaks. Hackly - jagged fractures with sharp edges. Uneven or Irregular - rough irregular surfaces Colour Color is sometimes an extremely diagnostic property of a mineral, for example olivine and epidote are almost always green in color. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] But, for some minerals it is not at all diagnostic because minerals can take on a variety of colors. These minerals are said to be allochromatic. For example quartz can be clear, white, black, pink, blue, or purple. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Streak Streak is the color produced by a fine powder of the mineral when scratched on a streak plate. Often it is different than the color of the mineral in nonpowdered form Hematite: red; Limonite: brown; Magnetite: dark gray; Chromite: brown; Magnetite: dark gray; Chromite: brown Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Luster Luster refers to the general appearance of a mineral surface to reflected light. Two general types of luster are designated as follows: Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Metallic - looks shiny like a metal. Usually opaque and gives black or dark colored streak. Non-metallic - Non metallic lusters are referred to as vitreous - looks glassy - examples: clear quartz, tourmaline resinous - looks resinous - examples: sphalerite, sulfur. pearly - iridescent pearl-like - example: apophyllite. greasy - appears to be covered with a thin layer of oil - example: nepheline. silky - looks fibrous. - examples - some gypsum, serpentine, malachite. adamantine - brilliant luster like diamond. Structure Kidney, chordal, chordal radial, concussion, lump and concentric. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Kidney : Chalcedon, hematite Chordal: Asbestos, gypsum, calcite, Radial: Antimuan, Chordal radial: Pyrite, barite Concussion: Calcite, agate, pyrite, agate, Lump: Flintstone Concentric: Agat, Calcedon Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Specific Gravity Density refers to the mass per unit volume. Specific Gravity is the relative density, (weight of substance divided by the weight of an equal volume of water). In cgs units density is grams per cm3, and since water has a density of 1 g/cm3, specific gravity would have the same numerical value has density, but no units (units would cancel). Specific gravity is often a very diagnostic property for those minerals that have high specific gravities. In general, if a mineral has higher atomic number cations it has a higher specific gravity. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Specific Gravity Mineral Composition Atomic # of Cation Specific Gravity Aragonite CaCO3 40.08 2.94 Strontianite SrCO3 87.82 3.78 Witherite BaCO3 137.34 4.31 Cerussite PbCO3 207.19 6.58 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Specific Gravity Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Mineral Composition Specific Gravity Specific gravity can usually be qualitatively Graphite C 2.23 measured by the heft of a mineral, in other Quartz SiO2 2.65 words those with high specific gravities Feldspars (K,Na)AlSi3O8 2.6 - 2.75 usually feel heavier. Fluorite CaF2 3.18 Topaz Al2SiO4(F,OH)2 3.53 Most common silicate minerals have a specific gravity between about 2.5 and 3.0. Corundum Al2O3 4.02 These would feel light compared to minerals Barite BaSO4 4.45 with high specific gravities Pyrite FeS2 5.02 Galena PbS 7.5 Cinnabar HgS 8.1 Copper Cu 8.9 Silver Ag 10.5 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Radioactivity The radioactivity in the minerals comes from the uranium (U) and thorium (Th) found in them. Some elements such as potassium (K) and rubidium (Rb) also have a small amount of radioactivity. It is aimed to determine the geological age by making use of the radioactivity feature in minerals. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Chemical properties of the minerals Minerals have a special composition It is determined by qualitative and quantitative analyzes and indicated by related formulas. The same chemical composition, a different crystal system polymorphism (multidimensionality) is used. Calcite with aragonite and diamond with Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] graphite are polymorph minerals. If minerals have the same shape but they have different chemical composition, isomorphism (coordination) is used. Calcite (CaCO3) dolomite (CaCO3.MgCO3) and siderite (FeCO3) are isomorphic minerals Optical properties of the minerals The light-related properties of the minerals make up the optical properties of minerals. Optical propeties of the minerals provides colours, fracture properties, single and double breaking properties, and the shapes they show under a polarizing microscope. Apart from these properties of minerals, some minerals have their own unique characteristics. Some minerals are magnetic, some minerals are radioactive, some minerals are good conductors, and some Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] minerals are poor conductors. Some minerals have piozoelectric properteis. Industy benefits from these properties of the minerals. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE OF MINERALS FOR CIVIL ENGINEERING Many minerals are used as building materials in the construction industry. The concrete is generally obtained with a mixture of gravel, sand, cement and water Aggregate (aggregate): sand, gravel, crushed stone (blasted rock), slag (slag) as concrete (concrete) course used for the construction or artificial or both types Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE often broken in various sizes up to 10cm or broken granular material stack (sand + gravel + natural rock material consisting of crushed stone). Gypsum (gypsum); (CaSO4.2H2O-Mohs hardness 2); colorless or white color is converted into plaster losing some of the water at 120 ° C. Plaster is used in indoor and outdoor applications. Various clay minerals have been used in mud bricks, bricks, tiles since ancient times. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE OF MINERALS FOR CIVIL ENGINEERING Pale limestone which is white or black without include silisium and clay is used for making lime Lime is used as a binder in mortar and also in stabilization of roads. Limes which are found various colour and pattern and well polished are used as coating materials in the buildings Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Apart from this, the mechanical behavior of the clays directly reflects on the structures and causes the forces to deform the structures. OF MINERALS FOR CIVIL ENGINEERING The concrete is generally obtained with a mixture of gravel, sand, cement and water depending on the importance and size of the engineering structure to be built, the chemistry of each of these components forming concrete may be primary importance. Especially aggregate (sand-gravel) which is added to concrete and constitutes 75-85% by weight of concrete is either naturally extracted from the earth's crust or artificially broken by rock masses. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE If quartz sand and pebbles are to be used as aggregates in a dam body concrete, they must be well studied. The high alkaline cement in the concrete is affected by the hydration caused by the hardening of the concrete and the alkali such as sodium-potassium in the cement are released. Quartz, opal, chalcedony, agate, tridimite sand and gravel composed of siliceous minerals and silicates interact with the alkalis released in the concrete, cause expansion, cracking and fracturing of the concrete. This results in concrete can be easily damaged by being non-resistant against external influences. The volume percentages of the silica minerals constituting the aggregate component in the concrete are as follows; Opal 0,20%; Calcinedon 5%; Acid volcanic mass% 3 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE AEarth’s internal structure 3 distinct divisions: Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE crust Oceanic 0-6 km (“young”, < 180 m.y.) Continental 0-34 km (older, up to 3.8 b.y. ) mantle Upper 34-670 km Lower 670-2900 km core Outer – Liquid Inner – Solid Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Earth's Structure and Tectonics Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Why do mantle convection currents exist? Force/Factor Description Role in Magma Migration Importance Caused by the density difference between magma Buoyancy Drives magma upwards due to its lower density compared to the crust High and solid rock Movements at plate boundaries (divergent, Tectonic Forces Provides pathways (fractures, faults) for magma to ascend High convergent) and faults Pressure decreases as magma rises, causing further Pressure Release (Decompression) Enables continued magma rise as surrounding pressure reduces High melting Dissolved gases in magma expand as pressure Gas Expansion (Volatiles) Helps push magma towards the surface, especially in volcanic eruptions High decreases Thermal Gradients Heat flow from the Earth's interior to the surface Contributes to magma formation and movement towards cooler regions Moderate Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Structural Weaknesses Fractures, faults, and weak zones in the crust Provides lower resistance pathways for magma to flow through Moderate Due to Earth’s rotation, creating a slight bulging at Centrifugal Forces Negligible influence on magma migration Low the equator Earth’s Rotation Creates the Coriolis effect, influencing surface fluids Minimal to no impact on deep mantle and magma migration Low Thus, mantle convection currents cause the movement of hot material upward and cooler material downward within the mantle. This process drives the horizontal movement of tectonic plates, which in turn contributes to geological Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE processes like subduction, mountain formation, and volcanic Rock Cycle activity. These tectonic movements are key drivers of the rock cycle, leading to the formation and transformation of: Igneous/Magmatic rocks, Metamorphic rocks, Sedimentary rocks. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE https://www.tes.com/teaching-resource/the-rock-cycle-power-point-6118894 Geologic Origins Igneous Rocks Sedimentary Rocks Metamorphic Rocks Granite Limestone Marble (Intrusive) (Calcium Carbonate) (Limestone) Basalt Shale Slate (Extrusive) (Clay) (Shale) Sandstone Quartzite (Quartz) (Sandstone) Gypsum Gneiss (Calcium Sulphate) (Granite) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Fig.2.9 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] MAGMA THE IMPORTANCE IGNEOUS Solidification MAGMA Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Granite IGNEOUS Plutonic (Intrusive) Diorite Solidificat MAGMA Gabbro Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Basalt Volcanic (extrusive) IGNEOUS Plutonic (Intrusive) Obsidian Solidification MAGMA Pumice Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Erosion Uplift Volcanic IGNEOUS Plutonic Solidification Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE SEDIMENT Erosion Uplift Volcanic IGNEOUS Plutonic Solidification Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE SEDIMENT Erosion Erosion Transport Uplift Volcanic Deposition IGNEOUS SEDIMENTARY Plutonic Solidification Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] SEDIMENT THE IMPORTANCE Erosion Burial/Compaction Uplift Volcanic Cementation IGNEOUS SEDIMENTARY Plutonic Solidification MAGMA Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE SEDIMENT Erosion Burial/Compaction Uplift Volcanic Cementation IGNEOUS SEDIMENTARY Plutonic Increased P&T METAMORPHIC Solidification Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE SEDIMENT Erosion Burial/Compaction Uplift Volcanic Can you see Cementation IGNEOUS any shortcuts? SEDIMENTARY Plutonic Increased P&T METAMORPHIC Solidification Dr. Moheldeen HEJAZI Melting 10/24/2024 [email protected] [email protected] THE IMPORTANCE SEDIMENT Erosion Burial/Compaction Uplift Volcanic Cementation IGNEOUS SEDIMENTARY Plutonic Increased P&T METAMORPHIC Solidification Dr. Moheldeen HEJAZI Melting 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE It affects all civil structures and infrastructures. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Weathering ▪ Mechanical Weathering ▪ Physical disintegration of rock (with no chemical alteration) ▪ Chemical Weathering ▪ Chemical alteration of minerals within the rock ▪ Usually softening or dissolving the minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Forming clays, oxides and solutes Types of mechanical Weathering Type of Mechanical Description Common Locations Impact on Rocks Weathering Water freezes in cracks, expands, and Frost Wedging Temperate climates, high altitudes Creates jagged rock fragments breaks rocks Rock expands when heated and Deserts, areas with large temperature Thermal Expansion Surface cracking and exfoliation contracts when cooled ranges Removal of pressure causes rock layers Exfoliation Mountain regions, large igneous rocks Formation of exfoliation domes to peel away Rocks are worn down by friction and Smooths and rounds rock Abrasion Rivers, coastal areas, deserts, glaciers impact particles Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Biological Activity Plant roots and animals break rocks Vegetated areas, biologically active zones Cracking and breaking of rock Salt crystals grow and exert pressure in Salt Crystallization Coastal regions, arid areas Granular disintegration cracks Physical forces from falling rocks and Creates sharp, broken Impact and Pressure Mountainous and steep regions landslides fragments AGENTS OF PHYSICAL WEATHERING 1. Frost Action -The freezing and thawing causes alternate expansion and contraction of rocks eventually breaking them Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE apart. Dominate in mountain or polar regions. More likely to occur in winter Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE The result of Mechanical weathering Rock falls and slides Crushing and abrasion (more mechanical weathering) Dr. Moheldeen HEJAZI Rock Avalanches Water volume 10/24/2024 [email protected] [email protected] Slopes of rock fragments may let go and careen THE IMPORTANCE increases by 9% when it freeze Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 10/24/2024 Dr. Moheldeen HEJAZI [email protected] [email protected] Talus Slopes THE IMPORTANCE ▪ The result of ▪ Mechanical weathering ▪ Rock falls and slides ▪ Crushing and abrasion (more mechanical weathering) ▪ Rock Avalanches ▪ Slopes of rock fragments may let go and careen downhill as a very fast flow Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE MECHANICALWEATHERING Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Ice Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Salt crystal Dr.growth Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE As salt crystals gradually grow larger, they weaken the rock by pushing apart surrounding grains or enlarging tiny cracks Unloading Pressure release forms sheet joints and exfoliation Sheeting is caused by the expansion of crystalline rock as erosion removes the overying material, a process termed unloading Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Mechanical Weathering An exfoliation dome in Yosemite, CA (Half Dome) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 2. Biological Action - With plant growth the root system will increase in volume and cause cracks in the rock to expand. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Lichens (fungi and algae) are primary soil producers. They create conditions for larger Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE plant growth. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Chemical Weathering - when agents of weathering chemically change the composition of a rock. II. AGENTS OF CHEMICAL WEATHERING 1. Oxidation – Oxygen combines with minerals to form oxides. (iron + oxygen = Rust) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Oxidation weakens the bedrock making it softer. ▪ Chemical Weathering Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Dissolving  Dissolved ions ▪ Oxidation  Iron in Ferromag. Minerals  Iron Oxides (e.g., Hematite) ▪ Formation of Clays from silicates (e.g., Feldspar) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 2. Hydration- minerals absorb water and chemically change the composition of the material Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 3. Carbonation – When pollutants like Carbon Dioxide, Nitrogen & Sulfuric Oxides mix with rain water creating acid rain, which can dissolve limestone and harm the living environment. ▪ Coal Burning For Electricity ▪ Fossil Fuel Consumption for Cars Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 4. Water - Is unique and dissolves most minerals and metals in our environment. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Chemical weathering: ion exchange and the chemical breakdown of feldspar Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Chemical Weathering Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE  Hydrolysis Oxidation: 4FeSiO3 + O2 + H2O  FeO(OH) + 4SiO2 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Hydration: CaSO4 + 2H2O  CaSO4·2H2O Factors affecting weathering ▪ Climate ▪ Different climates and temperatures produce more favorable forms of weathering. ▪ Chemical weathering is more prevalent in warm, wet tropical climates Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Humid Climates are moist and the rate of weathering is fairly fast. ▪ Mechanical weathering less important here ▪ Mechanical weathering is more prevalent in cold, relatively dry regions ▪ Arid Climates are very dry and the rate of weathering is slow ▪ Chemical weathering occurs slowly here ▪ Usually in the presence of heat weathering rates will also increase. Factors affecting weathering: Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE color dots on map match colors on chart Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Cold and Humid -Physical weathering is dominate at high latitudes altitudes, or in the winter. -Frost Action and Glacial Abrasion Hot and Humid - Chemical weathering is dominate near the equator and in the summer. -Oxidation, Hydration Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Hot & humid Dr. Moheldeen HEJAZI climates can also 10/24/2024 [email protected] [email protected] THE IMPORTANCE In theHEJAZI Dr. Moheldeen mountains and at the poles physical 10/24/2024 [email protected] [email protected] THE IMPORTANCE weathering like frost action and abrasion are more likely. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 2.Particle Size and Shape as particle size decreases the weathering rate increases - When the surface area increase, more sides are able to react with the elements Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Angular Sediments have more surface area. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE -weather at a faster rate. Round sediments have less surface area - weathering rate decreases. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 3. Mineral Composition - some rocks are resistant to weathering because of their composition Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI More Resistant 10/24/2024 [email protected] [email protected] THE IMPORTANCE Rocks will weather at different rates due to their chemical compositions. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Granite w/ strong chemical Limestone w/ weak Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE chemical composition (hard rock) composition (soft rock) ▪ Rock composition ▪ Minerals weather at different rates ▪ Calcite weathers quickly through dissolution ▪ Quartz is very resistant to chemical and mechanical weathering ▪ Mafic rocks with ferromagnesian minerals weather more easily Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Rock structure ▪ Distribution of joints influence rate of weathering ▪ Relatively close joints weather faster Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Topography ▪ Weathering occurs faster on steeper slopes ▪ Rockslides Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Vegetation ▪ Contribute to mechanical and chemical weathering ▪ Promotes weathering due to increased water retention ▪ Vegetation removal increases soil loss Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Vegetation can both hold water Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE And increase weathering. If removed Rocks may also be vulnerable to abrasion Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Silicate Structure Isolated Silicate Olivine Structure Single Chain Pyroxene Structure Group Double Chain Amphibole Structure Group Mica Group Sheet Structure Clay Group Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Feldspar Framework THE IMPORTANCE ▪ Stable at High Temperatures ▪ Quickly Weathered ▪ SlowlyWeathered ▪ Stable at Atmos. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Temperatures IV. Products of Weathering - sediments and soils 1. Sediment Types a. Solids – Are clastic sediments such as pebbles, sand, silt, or clay b. Colloids – Are suspended clay size particles c. Ionic Solutions – Are dissolved compounds in water Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Products of Weathering ▪ Clay ▪ Tiny mineral particles of any kind that have physical properties like those of the clay minerals ▪ Clays are hydrous alumino-silicate minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ▪ Sand ▪ A sediment made of relatively coarse mineral grains ▪ Soil ▪ Mixture of minerals with different grain sizes, along with some materials of biologic origin ▪ Humus ▪ Partially decayed organic matter in soil 2. Soil Types a. Residual – Soils formed from the weathering of the local bedrock and have the same mineral composition. b. Transported - Soil that has been moved & the sediments Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE are not of the same composition as the local rock Soil Horizons A. Top layer rich in organics & minerals from biologic activity. B. Sediments with minerals dissolved from above are found here. C.Mostly un-weathered bedrock. Soil development from local bedrock. Stage 1 Mostly un-weathered bedrock Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Stage 2 Development of top soil by biologic activity Stage 3 Mature thick and well developed soil horizons Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Soil is non-renewable resource 1 inch is made for every 100 years in New York Different climates produce different soil types Form at different rates. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] DifferentialWeathering THE IMPORTANCE John Ford Point Monument, Arizona. Ship Rock, New Mexico VolcanicNeck Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Main minerals found in rocks Rocks: Assemblages of minerals or stone fragments, formed by either multiple minerals or large accumulations of a single mineral. Primary Minerals: Major components influencing rock classification. Approximately 20–30 types, including quartz, feldspar, nepheline, and olivine. Accessory Minerals: Minor constituents with minimal influence on rock naming, such as tourmaline, magnetite, and zircon. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Secondary Minerals: Formed from primary minerals due to environmental processes like decomposition, metamorphism, and melting. Examples include kaolin, serpentine, chlorite, and zeolite. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Mineral Quartz Chemical Composition SiO₂ Crystal System Hexagonal Cleavage ± None Hardness (Mohs) 7 Density (g/cm³) 2.65 Classification Primary Orthoclase-Sanidine KAlSi₃O₈ Monoclinic Good, very good 6 2.56 Primary Albite NaAlSi₃O₈ Triclinic Very good 6 2.62 Primary Anorthite CaAl₂Si₂O₈ Triclinic Good 6 2.72 Primary Nepheline NaAlSiO₄ Hexagonal Weak 6 2.6 Accessory Leucite KAlSi₂O₆ Cubic Weak 6 2.47 Accessory Biotite K(Mg,Fe)₃(AlSi₃O₁₀)(OH)₂ Monoclinic Very good 2.5 2.8 Primary Muscovite KAl₂(AlSi₃O₁₀)(OH)₂ Monoclinic Very good 2.5 2.9 Primary Chlorite (Mg,Fe,Al)₆(Al,Si)₄O₁₀(OH)₈ Monoclinic Very good 2.5 2.60-3.30 Secondary Augite Ca(Mg,Fe,Al)(Al,Si)₂O₆ Monoclinic Good 6 3.25-3.55 Primary Enstatite MgSiO₃ Orthorhombic Good 6 3.20-3.90 Primary Hornblende NaCa₂(Mg,Fe,Al)₅(Si,Al)₈O₂₂(OH)₂ Monoclinic Good 6 3.0-3.4 Primary Pyrope Mg₃Al₂(SiO₄)₃ Cubic None 7-7.5 3.56 Accessory Almandine Fe₃Al₂(SiO₄)₃ Cubic None 7-7.5 4.32 Accessory Olivine (Mg,Fe)₂SiO₄ Orthorhombic Indistinct 6.5 3.22 Primary Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Apatite Ca₅(PO₄)₃(F,Cl,OH) Hexagonal Indistinct 5 3.2 Accessory The Zircon Andalusite ZrSiO₄ Al₂SiO₅ Tetragonal Orthorhombic Indistinct Moderate 7.5 7.5 4.60-4.70 3.15 Accessory Accessory Calcite CaCO₃ Trigonal Very good 2.7 (3) 2.71 Accessory main Gypsum CaSO₄·2H₂O Monoclinic Very good 2 2.50-2.80 Secondary minerals found in the rocks Alkali Feldspar Plagioclase Feldspar Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Primary minerals in Igneous/Magmatic rocks; Silica Minerals: Quartz: Composed almost entirely of silica (SiO₂), often found in felsic igneous rocks. Feldspar Group: Orthoclase and Plagioclase: The two main types of feldspar, which are significant rock-forming minerals, especially in igneous rocks. Feldspathoid Group: Leucite, Nepheline, and Sodalite: These are silica-poor minerals that typically form in rocks with low silica content, often as substitutes for feldspar in alkaline igneous rocks. Pyroxene Group: Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Bronzite, Enstatite, Hypersthene, Augite, Diallage, and Diopside: This group includes important mafic minerals, rich in iron and magnesium, commonly found in basalt and gabbro. Amphibole Group: Hornblende: A common amphibole mineral found in igneous and metamorphic rocks, distinguished by its complex silicate structure. Mica Group: Biotite and Muscovite: Layered silicate minerals known for their sheet-like structure; biotite is rich in iron and magnesium, while muscovite is aluminum-rich and lighter in color. Olivine Group: Olivine (Peridot): An iron-magnesium silicate found in ultramafic rocks and often in mafic rocks, giving them a greenish color. Primary minerals in sedimentary rocks Primary Minerals in Sedimentary Rocks Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 1. Rock Fragments Magmatic and Metamorphic Rock Fragments: Primarily quartz and feldspar. 2. Clay Minerals Includes various clay mineral types. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 3. Carbonate Minerals Calcite Dolomite 4. Iron Minerals Siderite Limonite Conglomerate section Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Primary minerals in metamorphic rocks 1. Silicate Minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI [email protected] [email protected] Quartz 10/24/2024 THE IMPORTANCE Feldspar Biotite Muscovite Hornblende Epidote Garnet Sillimanite Andalusite 2. Carbonate MineralsCalcite 3. Phyllosilicate Minerals Serpentine Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Talc Chlorite Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Secondary minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Ilmenite Magnetite Apatite Tourmaline Zircon Rutil Dr. Moheldeen HEJAZI The most important [email protected] [email protected] 10/24/2024 ones are Tourmaline, Magnetite, Ilmenite, Rutil, Apatite, THE IMPORTANCE Zircon and Topaz. Topaz Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Quartz Group Occurrence: Found in magmatic, metamorphic, and sedimentary rocks. Properties: Crystal System: Hexagonal Density: 2.65 g/cm³ Hardness: 7 (Mohs scale) Cleavage: None; exhibits unique twinning and conchoidal, glassy fracture surfaces. Chemical Resistance: Resistant to acids, except hydrofluoric acid. Color and Inclusions: Typically colorless and transparent; impurities can add color, and some varieties contain liquid or gas inclusions. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Industrial Uses: High-Purity Quartz: Used in optics, chemicals, and ceramics. Color Varieties: Necef taşı, amethyst, citrine, agate, etc., are popular for ornamental applications. Quartz Group Quartz Varieties: Key types include chalcedony, chrysoprase, heliotrope, agate, flint, jasper, silicified wood, and opal. Quartz rich aggregate as a civil engineering material: When using quartz rich sand and gravel as construction materials, comprehensive analysis is essential. Alkali-Silica Reaction (ASR): When quartz and its varieties are used as aggregates in cement, especially with high-alkali cement, ASR occurs. This reaction releases alkalis like sodium (Na) and potassium (K). Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Impact on Concrete: Silicates, particularly opal, chalcedony, and agate, react with these alkalis, leading to concrete expansion, cracking, and a reduction in structural strength. Structural Considerations: Cement-aggregate reactivity must be assessed based on the size and criticality of the structure. Quartz Group High-alkali cement + aggregate ↓ During hardening, hydration reactions occur ↓ Alkalis (Na, K, etc.) are released ↓ They react with silicate and siliceous minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE ↓ Expansion, cracking, and disintegration develop in the concrete. Strength decreases. Alkali-Silica Reaction (ASR): The alkalis (sodium and potassium) in high-alkali cement react with amorphous silica in aggregates to form an alkali-silica gel. Resulting Issues: The gel is hygroscopic, meaning it absorbs water and expands, which can cause significant internal pressure, leading to cracks and eventual disintegration of the concrete. Alkali-silica Reaction (ASR) Examples Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI [email protected] [email protected] Alkali-silica Reaction 10/24/2024 (ASR) Examples THE IMPORTANCE Abundance: Comprises 40-50% of the Earth's crust. Composition: Potassium-sodium-calcium aluminum silicate. Crystal System: Monoclinic or Triclinic. Cleavage: Exhibits cleavage in two directions, characterized by the angle between cleavage planes. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Types of Feldspar: Orthoclase Plagioclase Plagioclase Group Composition: Composed of a mixture of Albite and Anorthite in varying proportions. Crystal System: Triclinic Physical Properties: Color: Variable Fracture Faces: Glassy Hardness: 6 to 6.5 Specific Gravity: 2.60 to 2.76 Occurrence: Present in varying proportions in magmatic rocks and plays a crucial role in their classification. Also found in metamorphic and sedimentary rocks. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Orthoclase Group Crystal System: Monoclinic Significant Mineral: Orthoclase Nomenclature is based on the percentage of Na and Ca in the compositions. The main minerals of this group are; 1. Albite (NaOAl2O3), (90-100% Albite + 0-10% Anorthite) Oligoclas 3. Andesine (50% Albite + 50% Anorthite) 4. Labrador 5. Bitovnit Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE 6. Anorthite (CaOAl2O32SiO2), (90-100 Anorthite + 0-10% Albite) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Decomposition of feldspar;  As a result of the decomposition events, quartz occurs with clay minerals that are soluble in water.  Factors affecting decomposition; Climate, temperature, humidity, the effect of superficial acid waters and fumerols or hydrothermal processes which are deeply magic.  The shape and depth of the variable increase in volume is the result of decomposition of 5-30%.  The carrying capacity of the decomposition mass and pressure resistance are reduced. When building on such masses, it is necessary to pay attention to disintegration events. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Kaolinization - argillisation Feldspar + (CO2 + H2O) + climate (temperature-humidity) + surface acidic waters ↓ Clay minerals (kaolin) + quartz ± zeolite + 5–30% volume increase ↓ Decrease in load-bearing capacity and compressive strength Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Rock forming minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Oxygen %46.6 Rocks is assemblies of minerals, it is Silicon %28.2 formed by various minerals or rock fragments come together or consists of Aluminum %8.3 a large number of accumulations of a single mineral. Iron %5 Calcium %3.63 It is found in the majority of 8 element minerals as rock builder, representing Sodium %2.83 more than 98% of the weight of the Potassium %2.59 continental crust. Magnesium %2.09 Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI The rocks10/24/2024 that [email protected] [email protected] up the Earth's crust are the various minerals or single minerals, rock fragments, or both mineral THE IMPORTANCE and rock fragments. For example, Magmatic rocks such as granite, gabbro, syenite are formed by minerals; marble, quartzite is formed by a single mineral; various types of sandstones and conglomerates are formed by rocks and minerals. The rocks are studied according to their formation conditions and their origins; Magmatic rocks; Sedimentary rocks; Metamorphic rocks; Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Rock forming minerals Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE RockIMPORTANCE Cycle Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Igneous/Magmatic Rocks If the hot and fluid melt "magma" found in the depths of the earth is cooled or crystallized, it is called as "Magmatic rocks" Magma contains O, Si, Al, Fe, Ca, Mg, Na, K together with water, other rare earth elements as well as CO2, SO2 in vapor form. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic Rock Forming Minerals Main minerals; Quartz, feldspar (orthoclase, plagioclase), nepheline, sodalite, leucite, mica, muscovite, biotite, pyroxene, amphibole olivine. Accessory minerals; Zircon, sifen, magnetite, ilmenite, hematite, apatite, pyrite, rutile, corundum, garnet. Acidic (felsic) if it contains 65% silica and a large amount of aluminum, sodium, potassium and a small amount of calcium, iron and magnesium; Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Neutral (intermediate) if it contains 52-65% silica; It is possible to call it basic (mafic) component magma if it contains more than 45-52% of silica, calcium, iron and magnesium. The basic magma often reflects the composition of the mantle source area. The oceanic crust is a basic compound and richer in Fe and Mg elements. Therefore oceanic crust is more intense than the continental crust and the asthenosphere directly owned properties hosting site. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE The continental crust, on the other hand, consists of minerals rich in silicon and aluminum. While the magma that passes through the continental crust, it takes the material from the crust in its place. As a result of this, its composition returns from basic to neutral and acidic composition. Therefore, magmatic rock in the continental crust is richer and less intensive in terms of SiO2 mineral. Magmatic rocks The change in the amount of SiO2 in the bodies of magmatic rocks causes significant changes in the color of the rocks. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE The minerals and rocks rich in basic iron and nickel elements are darker, while minerals and rock which is acidic in nature and the richer in SiO2 are lighter. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks The composition of the magmatic rock develops depending on the composition of the last melt crystallized the rock. If the melt is poorly silicic, the rocks consist poorly siliceous and richly dark ferromagnesite minerals, they are formed by dark colored rocks in the melt. For example, Gabro Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE If the ratio of silica is high, quartz crystals are formed because the rocks are rich in silica and they have so less dark colored minerals All of the magmatic rocks such as peridotite can be composed of ferromagnesian (dark colored) minerals. The composition of these rocks is not the same as the composition of the melt. Magmatic rocks The magma, which is hot and fluid, moves in different depths under different composition and pressure. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Plutonic rocks are formed underground. They involve the "intrusion" or insertion of magma between other rocks, which then cools below the surface. Volcanic rocks are formed above ground. They involve the "extrusion" or eruption of magma, which then is called "lava." The lava cools upon or very close to the surface. Volcanic rocks can also form from "ash", which is simply pulverized rock blown into the air (not like the "ash" that results from burning wood) -- larger rocks are "bombs. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks Intrusive rocks; They are sturdy and durable (because they are made of crystal only) Granite, syenite Extrusive rocks; It is semi-crystalline and the crystals are floating in a dough Andesite, rhyolite, basalt Semi-deep rocks; They form a transition between the depth rocks and the surface rocks. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE The slurry is not glassy, and other rocks are composed of small crystals in cracks and crevices are located. Granitporphyr, quartosporphyr, syenitporphyr Magmatic rocks Plutonic rocks; crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form. Examples of intrusive igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE After occurring solidifies dozens or even hundreds over the years up to millions continental uplift as a result of erosion of sediments that can reach several kilometers thick on them as a result of wear of such rocks are seen today on the ground surface in the current topography. Çavuşbaşı granodiorite pluton on the Anatolian side of Istanbul and granite pluton of Gebze-Sancaktepe. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks Semi-deep rocks; Magmatic rocks are called semi-deep rocks as the magmatic rocks which eventually solidify on the earth in the course of upward movement following the discontinuities such as cracks and cracks in the upper part of the lithosphere. Intrusive rocks consist of coarse, very coarse grains of crystals that develop due to slow cooling and less pressure in spaces and cracks at depths near the earth. Granite pegmatite, gabbro pegmatite, etc. named. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks Commonly observed forms of intrusive rocks observed in the field are: dykes, sills, laccoliths, bysmaliths, phacoliths, lopolith, volcanic necks, batholiths and chonoliths. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE DYKES: Dykes and sills are the most common forms of the intrusive Magmatic bodies. They are discordant Cut across the bedding of the rocks in which they intrude Vertical to steeply inclined and sheet like body (extensive in lateral dimension) Thickness vary widely from an inch up to hundred of feet Injected through fractures, joints, and weak planes Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Quartz-Dolerite dykes of Midland valley of Scotland are about 50-60 km long and up to 30m thick. Few places some dykes are very short up to few meters and as thin as few cm. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] Mafic THE IMPORTANCE dyke Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE SILLS: Sills are relatively thin tabular sheet like body that penetrates parallel to the bedding planes. Laterally it may extends for 100s of km and up to 10 km in width. Lateral extend mainly depends on the hydrostatic force, temperature, degree of fluidity or viscosity, weight of overlying sediment column. Since basic magma are more fluid then acidic magma- mostly sills are made up of gabros, dolorites and basalts Spreads parallel to the bedding planes of the rocks, hence concordant in nature. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] limestone sandstone THE IMPORTANCE mudstone LACCOLITHS: It is a concordant body, with flat bottom and convex upward. It is dome shaped. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE When viscous magma is injected rapidly along the bedding, as it cannot spreads it pushes up the overlying layers and keep on piling up. It causes folding of the overlying rock layers. BATHOLITHS: are the largest kind of plutons, irregular in shape and occupies large area. Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Their side sloping away from each other which makes them larger and large downwards extending to greater depth Their occurrence is commonly associated with the mountain-building process These are either granites or granodiorites in composition Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE and are associated with batholiths. PHACOLITHS: These are concordant bodies that occurs along the crests and troughs of the folded sedimentary strata. LOPOLITHS: These are basin or saucer-shaped concordant bodies with top nearly flat and convex bottom. They are very huge body with diameter up to 150 miles (app. 240 km) Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Lopolith Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Dr. Moheldeen HEJAZI 10/24/2024 [email protected] [email protected] THE IMPORTANCE Magmatic rocks Extrusive Magmatic rocks are rocks formed by cooling magma lavas near a surface with a chimney or by moving to the surface. The crystals are small because they cool quickly. They usually form a small crystalline matrix (porphyric

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