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					Luluhawa  batuan mendak
            Learning objectives

                          1 Apa itu
                6 hasil

 5 Impak/kesan                   2 Bagaimana
                                    terjadi
7 kepentingan    luluhawa

                                 3 Jenis2 luluhawa
   4 Faktor2 yg mempengaruhi
   luluhawa
Luluhawa – suatu proses yang
berlaku di permukaan bumi untuk
memecah dan menguraikan
batuan (break and decompose
rocks)
Enviromen: terhad kepada sejauh
mana air tanah (groundwater)
boleh menusuk masuk (penetrate)
ke dalam permukaan bumi
                luluhawa
 Boleh dilihat sebagai destructive forces
  - yang memecah, mengurai, mengubah
  bentuk dan keadaan fizikal dan kimia batuan
 Boleh dilihat sebagai constructive forces –
  yang menghasilkan sedimen, membentuk
  batuan mendak, mineral, mendapan
  mineral, landform baru
        Fakta asas luluhawa
 Berlaku perlahan sepanjang masa
 Mengambil masa yang lama
 Semua jenis luluhawa berlaku kadang2
  serentak dan tak terpisah satu sama lain.
  Dipisahkan untuk memudahkan
  pemahaman sahaja
 Keadaan di keliling menentukan segalanya
 Jenis2 luluhawa

1. Luluhawa fizikal
2. Luluhawa kimia
3. Luluhawa biologi
        1. Luluhawa fizikal

 Memecahkan batuan yang bersaiz besar kepada
  bahagian yang lebih kecil
  contoh: wedging (pembajian), exfoliation
  (pengelupasan), thermal expansion (kembang
  haba), lelasan (abrasion), (wetting and drying (esp
  in shales), pressure release by erosion of
  overburden
           Luluhawa fizikal
1 Frost wedging (pembajian ibun) – water
  expands when it freezes, breaking rocks
  into angular fragments; lazim berlaku
  dalam iklim temperat (ada ais)
  Nota: apabila air menjadi ais, isipadu
  meningkat sebanyak 10% => mebungkah
  (pries) batuan
talus – terdapat di kaki bukit
            Luluhawa fizikal
2 Exfoliation (pengelupasan) – bedrocks
  (batuan hampar) breaks into flat sheets
  along joints (kekar) which parallel the
  ground surface. This phenomenon is
  caused by expansion of rock when the
  pressure of overlying rock is removed by
  erosion => sometimes called unloading

                                Apa itu kekar?
Exfoliation Stone Mt
exfoliation
exfoliation
Active exfoliation Stone Mt
goblin
Mt Kinabalu
Mt Kinabalu
Mt Kinabalu
           Luluhawa fizikal
3 Thermal expansion (kembang haba) – heat
  causes action; cooling causes contraction
  => expand and contract at different rate
  causes stresses along mineral boundaries.
  Repeated heating and cooling => batuan
  pecah
       4    Lelasan (abrasion)
 Batuan menjadi lebih kecil hasi drpd
  pergeseran dan pelanggaran semasa
  terangkut, contohnya di dasar sungai
 Glasial, ombak dan angin juga boleh
  menjadi agen lelasan
     Kelebihan kimia fizikal

 Luluhawa fizikal memecahkan batuan ke
  saiz yg lebih kecil => menyediakan lebih
  banyak luas permukaan batuan bersaiz
  kecil untuk tindakbalas kimia berlaku
          2. Luluhawa kimia
 Memecahkan batuan secara kimia dgn
  menambah atau menanggalkan (removing)
  unsur2 kimia, mengubah unsur2 tersebut
  menjadi bahan2 baru
  contoh: dissolution (pelarutan), hydrolysis
  (hidrolisis), oxidation (pengoksidaan)
            Luluhawa kimia
1 Dissollution (pelarutan) – alters rocks by
  removing soluble minerals => soluble ions
  and insoluble ions => precipitate and
  crystallize (dalam tasik atau laut)
  Ex: pembentukan garam, batu kapur,
  travertine

Batuan => ion larut/ tak larut => pemendakan
           Luluhawa kimia
2 Hydrolisis – proses di mana feldspar are
  weathered to form clay
  Note: clay make up half of sedimentary
  rocks on Earth

   (Berapa jenis feldspar kita ada? Apakah
   komposisinya?)
Weathering of feldspar
     Beberapa contoh t/b kimia
A. Solution of carbon dioxide in water to form
   acid
   CO2 + H2O         H2CO3      H+ + HCO3-
B. Solution of calcite
   CaCO3 + CO2 + H2O          Ca2+ + 2HCO3-

C. CaCO3 + H+ HCO3-           Ca2+ + 2HCO3-
D. Chemical weathering of feldspar to form
    clay mineral
2KAlSi3O8 + 2H+ + 2HCO3- + H2O
K feldspar
 Al2Si2O5(OH)4 + 2K+ + 2HCO3- + 4SiO2
   clay mineral               Silica in solution
                                or as fine solid
                                particles
 Cara jurutera bahan mengungkap formula
 untuk memudahkan kefahaman

                K2O
2KAlSi3O8       Al2O3
                6SiO2


                Al2O3
Al2Si2O5(OH)4
                2SiO2
                2H2O
             Luluhawa kimia
3 oxidation – the process by which iron-
  bearing minerals (pyroxene, amphibole,
  biotite) weather to produce iron oxides
  Di kawasan tropik iron bearing
  aluminosilicate => lateritic soils, red clayey
  soils
             Oxidation reaction
4FeSiO3 + O2 +10H2O      4FeO.OH +
Fe pyroxene               Goetite
                                4H4SiO4

2Fe2SiO4 + 2O2 + 4H2O    4FeO.OH +
                           2H4SiO4
Fe olivine
         3. Luluhawa biologi
 Pemecahan batuan disebabkan oleh
  tindakan organisma hidup spt tumbuh2an,
  haiwan dalam tanah dan lichen (kulat? yang
  hidup di atas batuan dan kayu)


       Pengaruh => minimum
Hasil luluhawa
Weathering products
                Malaysia

 Average daily temperatures range from a
  minimum of 25o C to a maximum of 33o C.
 has an average annual rainfall of more
  than 2500 mm
         Hujan dan suhu
                          wettest




driest
 Mineral stability in the weathering
            environment
Mineral didapati tak stabil dalam enviromen
tertentu
Minerals which formed at high temperature
and pressures are least stable in the
weathering environment and weather most
quickly
Minerals which formed at lower temperatures
and pressures are most stable under
weathering conditions
Rates of weathering
              Soil profile




D horizon
Fresh rocks
Soil profile

 Eluviation
 illuviation
 leaching
 Leaching/larutlesap: proses kimia yang
  menghasilkan unsur larut dan tak larut.
  Yang larut akan lesap ke bawah dalam
  profil tanah sementara yang tak larut akan
  terkumpul di bahagian atas profil tanah =>
  warna membezakan lapisan tanah
 Eluviation: removal of materials dissolved
  or suspended in water
 Illuviation: horizon of maximum
  accumulation of suspended material or
  clay
 Chelation: pembentukan kompleks kimia
Laterite profile
Acid run-off at gold mine
bryce
Oxidation effect
Oxidation effects
Staglatite-staglamite
sinkholes
 Gred luluhawa (weathering grade), kekuatan
          ekapaksi dan rock-soil ratio

                                  UCS(MPa) RSR
Gred VI    tanah/soil
Gred V     completely weathered   <0.15      0-30
Gred IV    highly weathered       0.2-0.15   30-60
Gred III   moderately weathered   0.4-0.2    60-90
Gred II    slightly weathered     0.9-0.4    90-95
Gred I     Fresh rock                        95-100

                       Tengok transparensi lain
     Sinkholes (tanah benam)
 Bagaimana terjadi?
 Enviromental problem?
               Jenis2 tanah
 Residual soil - laterit, iklim tropik
 Transported soil – till, loess, iklim temperat

    Tanih -    pelbagai jenis tanah
              contoh: laterit, pedalfer, latosol,
              paleosol
     Wentworth scale   - grain size scale
   Particle name      Particle diameter Gravel
   Boulders           > 256 mm
   Cobbles            64 - 256 mm
   Pebbles            2 - 64 mm
   Granules           2 - 4 mm
   Sand
   Very coarse sand   1 - 2 mm
   Coarse sand        0.5 - 1 mm
   Medium sand        0.25 - 0.5 mm
   Fine sand          0.125 - 0.25 mm
   Very fine sand     0.0625 - 0.125 mm
   Silt               1/256 - 1/16 mm
                       (or 0.004 - 0.0625 mm)
 Clay                 < 1/256 mm
                       (or < 0.004 mm) sesetengah
                       buku guna takrif <2 mikron
Kitar batuan (Rock cycle)
        Hakisan (erosion)
The movement of weathered material from
the site of weathering. Primary agent is
gravity, but gravity acts in concert with
running water

pergerakan bahan terluluhawa dari tempat
luluhawa berlaku ke tempat ia ditemui
Sedimentary cycle
Malaysia bagaimana?
     Faktor yang mempengaruhi
        pembentukan tanah

1.   Iklim (climate)
2.   Batuan induk (parent material)
3.   Relief (keadaan permukaan bumi)
4.   Vegetation (tumbuhan)
5.   Masa (time)
Sambung => batuan mendak


  (lihat beberapa transparensi
  mengenai luluhawa)
              Apa kesudahannya?

  kepentingan                apa


                Batuan        Bagaimana
  jenis2
                mendak        terjadi
Ciri2 utama                        Di mana

      Perubahan sebelum, semasa dan
      selepas pembentukan
  Hasil drpd luluhawa ialah sedimen

 Sediment = loose particulate material (clay,
  sand, silt, gravel, etc.)
 Sediment becomes sedimentary rock
  through lithification, which involves:
 Compaction
 Cementation
 Recrystallization (of carbonate sediment)
     Wentworth scale   - grain size scale
   Particle name      Particle diameter Gravel
   Boulders           > 256 mm
   Cobbles            64 - 256 mm
   Pebbles            2 - 64 mm
   Granules           2 - 4 mm
   Sand
   Very coarse sand   1 - 2 mm
   Coarse sand        0.5 - 1 mm
   Medium sand        0.25 - 0.5 mm
   Fine sand          0.125 - 0.25 mm
   Very fine sand     0.0625 - 0.125 mm
   Silt               1/256 - 1/16 mm
                       (or 0.004 - 0.0625 mm)
 Clay                 < 1/256 mm
                       (or < 0.004 mm) sesetengah
                       buku guna takrif <2 mikron
Ternary diagram Sand-Silt-Clay
Kitar batuan (Rock cycle)
Pengelasan batuan mendak

1 Terrigenous (detrital or clastic) – bumi/benua
  –   Conglomerate or Breccia
  –   Sandstone
  –   Siltstone
  –   Shale
2 Chemical/biochemical
  – Evaporites
  – Carbonate sedimentary rocks (limestones and dolostone)
  – Siliceous sedimentary rocks
3 Organic (coals)
  – Other - ironstones
Classification of sedimentary rocks
          Hjulstrom Curve




Menghubungkait vel-size dgn proses (1939)
  A. Terrigenous (also called detrital or clastic)
   Terrigenous sedimentary rocks are derived from
   the weathering of pre-existing rocks, which have
   been transported to the depositional basin. They
   have a clastic (broken or fragmental) texture
   consisting of:
1. Clasts (larger pieces, such as sand or gravel)
2. Matrix (mud or fine-grained sediment
   surrounding the clasts)
3. Cement (the glue that holds it all together), such
   as:
    1.calcite
    2.iron oxide
    3.silica
Clasts and
matrix
(labelled),
and iron oxide
cement
(reddish brown
color)
 Sand: Grain size 1/16 to 2 mm
 Sandstone
 If dominated by quartz grains = quartz
  sandstone (also called quartz arenite)
 If dominated by feldspar grains = arkose
 If dominated by sand-sized rock fragment
  grains = lithic sandstone (also called
  litharenite or graywacke)
conglomerate
breccia
Quartz sandstone
Arkose (mengandungi banyak feldspar)
Greywacke (sand-sized rock
       fragments)
 Silt: Grain size 1/256 to 1/16 mm (gritty)
 Siltstone
 Clay: Grain size less than 1/256 mm
  (smooth) (< 2 micron)
 Shale (if fissile)
 Claystone (if massive)
  Note: Mud is technically a mixture of silt and
  clay. It forms a rock called mudstone (or
  mudshale if fissile).
shale
kaolin
 B. Chemical/biochemical Sedimentary
  Rocks
 This group includes the evaporites, the
  carbonates (limestones and dolostone),
  and the siliceous rocks. These rocks form
  within the depositional basin from chemical
  components dissolved in the seawater
 Evaporites - The evaporites form from the
  evaporation of water (usually seawater).
 Rock salt - composed of halite (NaCl).
 Rock gypsum - composed of gypsum
  (CaSO4.2H20)
 Travertine - composed of calcium
  carbonate (CaCO3), and therefore, also
  technically a carbonate rock; travertine
  forms in caves and around hot springs.
Bonneville Salt Flats of the Great Salt Lake, Utah. The lake
bed is covered with rock salt which gives it the white color.
      The salt is mined by the Morton Salt Company.
gypsum
Gypsum crystals, Marion lake,
         Australia
 Carbonates - The carbonate sedimentary rocks
  are formed through both chemical and
  biochemical processes. They include the
  limestones (many types) and dolostones.
 Two minerals are dominant in carbonate rocks:
  – Calcite (CaCO3) (batu   kapur)-mudah berbuih
    dgn asid lemah
                             digores jadi
  – Dolomite (CaMg(CO3)2) – perlu
    serbuk, baru bertindakbalas dgn asid
 Carbonate rock names:
 Micrite (microcrystalline limestone) - very fine-
  grained; may be light gray or tan to nearly black in
  color. Made of lime mud, which is also called
  calcilutite.
 Oolitic limestone (look for the sand-sized oolites)
 Fossiliferous limestone (look for various types of
  fossils in a limestone matrix)
 Coquina (fossil hash cemented together; may
  resemble granola)
 Chalk (made of microscopic planktonic organisms
  such as coccolithophores; fizzes readily in acid)
 Crystalline limestone
 Travertine (see evaporites)
 Others - intraclastic limestone, pelleted limestone
Stromatolitic limestone
Batuan karbonat di Mexico
 Siliceous rocks - The siliceous rocks are those
  which are dominated by silica (SiO2). They
  commonly form from silica-secreting organisms
  such as diatoms, radiolarians, or some types of
  sponges. Chert is formed through chemical
  reactions of silica in solution replacing
  limestones.
 Diatomite - looks like chalk, but does not fizz in
  acid. Made of microscopic planktonic organisms
  called diatoms. May also resemble kaolinite, but
  is much lower in density and more porous).
  Also referred to as Diatomaceous Earth.
 Chert - Massive and hard, microcrystalline
  quartz. May be dark or light in color. Often
  replaces limestone. Does not fizz in acid.
 . Organic Sedimentary Rocks (Coals)
 This group consists of rocks composed of organic
  matter (mainly plant fragments). Because of this, they
  lack minerals (which must be inorganic, be definition).
  These are the coals. In order of increasing depth of
  burial (temperature and pressure):
 Peat (porous mass of brownish plant fragments
  resembling peat moss)
 Lignite (crumbly and black)
 Bituminous coal (dull to shiny and black; sooty;
  layers may be visible)
 Anthracite coal (extremely shiny and black, may
  have a slight golden shine; low density; not sooty;
  technically a metamorphic rock due to high
  temperatures and pressures to which it has been
  subjected)
               others


There are several other interesting
sedimentary rock types: Ironstones -
Oolitic hematite, banded iron formations
Abundance of sedimentary rocks
               Soalan
Maklumat apakah yang boleh dicerap dari
pemerhatian batuan mendak?
Senaraikan…
              Sedimentary Structures
   Sedimentary structures form in the basin of
    deposition, as a result of the action of
    natural processes such as waves, currents,
    drying events, etc.
   Beds or strata
   Cross-bedding
   Graded beds
   Ripple marks
    -Current ripple marks (asymmetrical ripples)
    Oscillation or wave ripple marks
    (symmetrical ripples)
   Mud cracks
Structures formed during deposition
      1-4, after deposition 5,6
         1          2         3




         4              5         6
Ripple marks
Graded bedding, Jurassic of New
           Jersey
Graded bedding
                 halus


                 kasar

                 halus

                 kasar
mudcracks   bagaimana terjadi?
ripples
rounding
                  sorting




High energy enviroment   Low energy enviroment
varves
Cross stratification (berlaku semasa
 transgression-regression air laut)
             Important note
 Descriptive properties => interpretive
  properties
 Geology => engineering
 Objective: to aid planning, design,
  construction, mitigation, conservation,
  preservation
   Sedimentary Environments
 Sedimentary environments are places where
  sediments accumulate and sedimentary rocks
  form. They can be grouped into:
 Terrestrial environments (non-marine)
  – Rivers (fluvial environment)/sungai)
  – Alluvial fans (kipas lanar)
  – Lakes (lacustrine environment)/tasik
 - Swamps/paya
 - Deserts (aeolian environment)
 - Glacial environments
 Transitional environments (at the
  transition between the marine and non-
  marine environments)
 Beach and barrier islands
 Delta
 Lagoons
 Estuaries
    Marine environments
   Continental shelf
   Continental slope and rise (deep sea fans)
   Abyssal plain
   Reefs (karang)
Alluvial fan
Enviroment of sedimentary rx
SEDIMENTARY ENVIROMENTS
AGENTS &
 ENERGY
SOURCES
ALLUVIAL
WIND ACTION (Eolian)
Continental enviroment: fluvial
layering
beach
Marine environment
Depositional environments
Model for landform development
                  Fossils

 Fossils are the remains or traces of
  prehistoric life.
 Outcrop in Nova Scotia, Canada of the McCoy
  Brook Formation of Early Jurassic age in which
  a dinosaur skeleton was found (box) Drawing of
  the outcrop on left, emphasizing layering.
 Facies - the characteristics of a unit of
  sediments, which can be used to interpret
  the depositional environment.
           Batuan mendak
 Batuan hos kepada petroleum dan gas asli
 Mendapan mineral spt Cu, Pb, Zn, Tungsten
 dll
a bit about Si
 14                 www.webelements.com
  Si
  28.0855(3)The essentials
 Name: silicon
 Symbol: Si
 Atomic number: 14
 Atomic weight: 28.0855 (3) r
 CAS Registry ID: 7440-21-3
 Group number: 14
 Group name: (none)
 Period number: 3
 Block: p-block
 Description
 Here is a brief description of silicon.
 Standard state: solid at 298 K
 Colour: dark grey with a bluish tinge
 Classification: Semi-metallic

Silicon is present in the sun and stars and is a
principal component of a class of meteorites known
as aerolites. Silicon makes up 25.7% of the earth's
crust by weight, and is the second most abundant
element, exceeded only by oxygen. It is found
largely as silicon oxides such as sand (silica),
quartz, rock crystal, amethyst, agate, flint, jasper
and opal. Silicon is found also in minerals such as
asbestos, feldspar, clay and mica.
Silicon is important in plant and animal life.
Diatoms in both fresh and salt water extract silica
from the water to use as a component of their cell
walls. Silicon is an important ingredient in steel.
Silicon carbide is one of the most important
abrasives. Workers in environments where
silicaceous dust is breathed may develop a serious
lung disease known as silicosis.
              Important facts

 Hydrolysis and condensation of substituted
  chlorosilanes can be used to produce a very
  great number of polymeric products, or
  silicones. These range from liquids to hard,
  glasslike solids with many useful properties.
 Elemental silicon transmits more than 95%
  of all wavelengths of infrared and and has
  been used in lasers to produce coherent
  light at 456 nm.
    Isolation
   Here is a brief summary of the isolation of silicon.
   There is normally no need to make silicon in the
    laboratory as it is readily available commercially. Silicon
    is readily available through the treatment of silica, SiO2,
    with pure graphite (as coke) in an electric furnace.
   SiO2 + 2C Si + 2CO
   Under these conditions, silicon carbide, SiC, can form.
    However, provided the amount of SiO2 is kept high,
    silicon carbide may be eliminated.
   2SiC + SiO2 3Si + 2CO
   Very pure silicon can be made by the reaction of SiCl4
    with hydrogen, followed by zone refining of the resultant
    silicon.
   SiCl4 + 2H2 Si + 4HCl
Fakta penting mengenai Malaysia
Most cities and large towns in the
 Peninsula are located on a thin
surface alluvium over limestone
           and granite.
 Malaysia is generally formed by highland,
  floodplain, and coastal zones (Figure 1.2 ).
  In the Peninsula, the Banjaran Titiwangsa
  from north to south divides the West Coast
  and East Coast states, while in Sarawak the
  Banjaran Kapuas Hula and Banjaran Iran
  border Indonesia. All of these ranges are
  governed by virgin forest
 Malaysia is warm and humid throughout the
  year, as characterised by the equatorial
  climate, and has an average annual rainfall
  of more than 2500 mm with spatial variation
  shown in Figure 1 . 3 .
 In the Peninsula wettest area is Taiping in Perak
  whilst the driest is Kuala Pilah in Negeri Sembilan
  (Figure 1 . 5 ).
 Average daily temperatures range from a
  minimum of 25o C to a maximum of 33o C.
  Relative humidity is high, sometimes exceeding
  80%. Daytime cloudy hours are also high while
  haze lately is a frequent occurrence that will
  contribute to acid rains.
 Urbanisation poles are formed in many different
  ways including;
 ·      centrally in dense arrangements such as
  towns, cities, ports, commercial/business centres,
  and new development areas
 ·      linearly along road, highway, railway, river,
  estuary, and coastal areas
 ·      randomly located, including villages and
  high class residential areas
      Next lecture


on metamorphic rocks

				
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