Sedimentary Rocks and Weathering PDF

ST01502 EARTH SCIENCE (SAINS BUMI) SEDIMENTARY ROCKS & WEATHERING AND EROSION Guuh aa paden bat alipat cuaca.  *ZI – DR ZULHERRY ISNAIN *MFA – MOHD AL-FARID BIN ABRAHAM Carbonate cycles of early...

ST01502 EARTH SCIENCE (SAINS BUMI) SEDIMENTARY ROCKS & WEATHERING AND EROSION Guuh aa paden bat alipat cuaca.  *ZI – DR ZULHERRY ISNAIN *MFA – MOHD AL-FARID BIN ABRAHAM Carbonate cycles of early Pliocene age (Capo Bianco section, Sicily, Italy) Carbonate cycles of early Pliocene age (Punta di Maiata, Sicily, Italy)  ODP Leg 160 (1995) 963 964 965-968 972-973 969-971  (1) SEDIMENTARY ROCK Rock that made up of consolidated sediment. Sediments (refers to detrital/solid particles & chemical/dissolved minerals) that lithified and transformed into sedimentary rock. layering ↓ ada bil drivingor  How Sedimentary Rock Form? · timea · S pressure f & aliberta  Gatuan sedimen todedah Exposed rocks → Weathering → Sediments → Y9 Erosion → Transport → Deposition → Burial → Compaction → Cementation → Sedimentary rock  * (2) WEATHERING Defined as the physical breakdown & chemical alteration of earth materials as they exposed to the atmosphere, hydrosphere & biosphere. Yselalu benaken break Physical (mechanical) weathering – break into smaller pieces (sediments). (First mash Chemical weathering – changes the composition of weathered materials. (second organist Biological weathering – caused by organisms: plant roots & burrowing animals. (Lust] Physical Weathering  Physical Weathering ▪ Physical (mechanical) weathering – involves the keva direct breakdown of rocks through direct contact with atmospheric conditions, such as heat, water, ice, and pressure. ▪ Those that involve only physical changes only! ▪ Examples: a. Frost-wedging (Freeze-thaw) b. Thermal expansion and contraction c. Exfoliation d. Salt crystallization e. Biological activity  ↓ Satah Frost-wedging (Freeze-thaw): Water enters cracks in rocks, freezes, expands, and breaks the rock apart. din freeze tren bila air break ↓ expand lepast W  Thermal expansion and contraction: temperature changes cause rocks to expand and contract, leading to cracking and fragmentation.  Exfoliation: Layers or sheets of rock gradually peel away due to pressure release or thermal expansion.  Salt Crystallization: Salts crystallize in rock pores or cracks. As they grow, they exert pressure and break the rock.  Biological Activity: Plant roots can grow in cracks in rocks and pry them apart as they grow. alar masuh , bath pecal t physical weathering Chemical Weathering  Chemical Weathering  Involves the direct effect of atmospheric chemicals in the breakdown of rocks, soils, and minerals.  Chemical decomposition  Change mineralogy composition or form new mineral which are more stable/resistant (secondary mineral).  Type of chemical weathering processes: a. Hydration take stabil - nance mineral -b. Hydrolysis react dengan c. Carbonation T d. Oxidation dia alan chemicals with ~ e. Solution atmospheric - f. Acid-rain reaction jadi stabil  Hydration: attachment of water molecules to crystalline structure of a rock, causing expansion and weakness Example: The hydration of anhydrite to gypsum sea E lessStablarea  break down the water element hychogens - , oxygen : Hydrolysis C: combination of hydrogen and oxygen in water with rock to form new substances Example: The hydrolysis of potassium feldspar into kaolinite (a clay mineral), silica, and potassium: ↳ clay  - add carbon dioxide Carbonation: water + carbon dioxide + calcite dissolve into calcium ion and bicarbonate ion Biological activity in soil generates substantial CO2 Bicarbonate is the dominant ion in surface runoff. CO2N , Th ↳ limestone  O 2 saddition of oxygen , Oxidation: Oxygen dissolved in water promotes oxidation of sulfides, ferrous oxides, native metals.  Solution: process by which rock is dissolved in water Is strongly influenced by pH and temperature When water becomes saturated, chemicals may precipitate out forming evaporite deposits. Calcium carbonate (calcite, limestone), sodium chloride (salt), and calcium sulfate (gypsum) are particularly vulnerable to solution weathering.  Acid-rain rxn: caused by atmospheric pollutants, can react with minerals in rock-containing carbonate, leading to increased rates of weathering. Example: reaction of sulfuric acid (a component of acid rain) with calcium carbonate  Biological Weathering  bacteria ye buat Biological Weathering - Sunset [dishwa Narwan - Donoh > , Reaction of living organism toward increasing weathering rate by chemical or physical processes.  E.g. (Chemical processes) Desert varnish – dark staining characteristic (thick layer cover the rock) of rock surface in arid region. Action bacteria oxidize and concentrated certain element (Mn or Fe oxide or hydroxide).  E.g. (physical processes) the growth of tree roots penetrated, and enlargement of incipient rock fractures can contribute significantly to the breakdown of rock  (3) EROSION Process by which soil and rock are removed from the Earth's surface by exogenetic processes such as wind or water flow, and then transported and deposited in other locations Type of erosions: a. Geological erosion - b. - Accelerated erosion  Geological Erosion ▪ Natural erosion - is the action of the wind, water, ice and gravity in wearing away rock to form soil and shape the ground surface ▪ Has been taking place naturally for millions of years and it helps to create balance in uncultivated soil that enables plant growth ▪ Except for some stream and shore erosion, It’s a relatively a slow continuous process that often goes on unnoticed  Accelerated erosion ▪ concept referring to an essentially natural process occurring at an increased rate under conditions of ecological disequilibrium ▪ the speeding up of erosion due to human activity ▪ Whenever we destroy the natural vegetation or alter the contour of the ground without providing some sort of surface protection, we greatly increase the rate of erosion ▪ can be minimized through careful planning and by implementing Type of Accelerated erosion ▪ Sheet erosion ▪ Rill erosion ▪ Gully erosion sampai Is ni u ↓ Rill erosion Gully erosion selal je ↳ nauisan m ↳navisan ains ↳ hallisal gabr lembar (4) TRANSPORTATION Water & wind as agent for erosion & transportation. Transportation – movement of sediments due to gravity, wind/water.  (5) DEPOSITION & LITHIFICATION e removal ! Deposition – accumulation of sediments in area known as depositional environment: & floodplain, stream, beach, seafloor. Burial & compaction – more sediment layers deposited on top causes compaction which reduces pore spaces (water & air squeezed out) & grains pressed closer together. Cementation – precipitation of minerals in pore spaces from circulating water which bind the loose particles together.  Coarser sediments settled to the ground first followed by finer sediments. - tenendep solab graniti berat die hat - sape lagi , barrah ↓ CLASSIFICATION/TYPES OF SEDIMENTARY ROCKS turnalis ferangent & 25 , Clastic / detrital sedimentary rocks – made up of solid particles known as clasts (sand, gravel) derived from parent rock. Classified by the size of their constituent particles; gravel (> 2 mm), sand (2 - 1/16 mm), silt (1/16 - 1/256 mm), clay (< 1/256 mm). davi chemical alinat ↓ reaction Chemical sedimentary rocks – solution (compounds & ions) derived from chemical weathering are the raw materials for this rock – carbonate rocks (limestone, dolostone) & evaporites (gypsum, halite). animat organism & Biochemical sedimentary rocks – organisms with hard shells; calcite (CaCO3)-limestone, SiO2-chert. Coal originates from altered remains of land plants in swamps (less O2, organic matter accumulates faster than it decomposes). O ↓ buntit Identifying Sandstone and Mudstone More resistant to weathering Less resistant to weathering  Limestone Halite Chemical Rocks Gypsum batmanChert rijan  Fossiliferous Limestone Coquina Biochemical Rocks Coal  Sedimentary Structures – structures formed during sediment deposition Strata / Beds Mud cracks – dries then shrinks  Cross bedding – caused by wind/water currents X ↑ fina dia cross Sebah wind & current Graded bedding – caused by turbidity currents --- ↑ Ripple marks – caused by currents & waves ↳ Sebabhan ombet Sedimentary Structures (cont.) Fossils – Remains & traces of ancient life Animal Plant Trace fossils – imprint/mark left by organism  Important Resources in Sedimentary Rocks Sand and gravel – construction industry. Clay – ceramics. Limestone – cement. Iron ore – iron & steel industry. Coal – electricity. Hydrocarbons. > - oil gas hah ene neime  ITEL: Interactive Discussion Let's explore the beauty of Earth! 1. Share a picture of a sedimentary rock you find visually striking 2. Tell us about its journey from sediment to sheen rock. di 14 centerme Deadline: 7 December 2023 tr Batu Sapi, Sandakan  STUDY CASE: WEEK 14 Poster and group presentation: A study case on major global earthquake from 2013-2023 I told my friend a joke about sedimentary rock, but it was too layered for him to understand. Thank you! @alfaridabraham