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    Geologi Fisik(Batuan Beku)

    Oleh :

    Irvani

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Referensi :

    • Thomson, G. R. and Turk, J. 1991. Modern Physical Geology. SaunderCollege Publishing, USA.

    • Lutgens, F. K., Tarbuck, E. J. and Tasa, D. 2012. Essentials of Geology,11th Edition, Pearson Prentice Hall, New Jersey.

    • Freeman, T. 2004. Environmental Geology Laboratory. John Wiley & Sons,Inc., USA.

    • Monroe, J. S. and Wicander, R. 2009. The Changing Earth: ExploringGeology and Evolution. 5th Edition. Pre-Press PMG, USA.

    • Carlson, D. H., Plummer, C. C. and Hammersley, L. 2011. Physical Geology: Earth Revealed. 9th Edition. McGraw-Hill, New York.

    • Bates, R.L. and Jackson, J.A., 1987. Glossary Geology. 3th Edition. American Geological Institute Elexandria, Virginia.

    • Williams, L. 2004. Earth Science Demystified. McGraw-Hill, New York.

    • Frisch, W., Meschede, M. And Blakey, R., 2011. Plate Tectonics :

    Continental Drift and Mountain Building. Springer-Verlag Berlin Heidelberg.German.

    • DLL

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Materi :

    - Pendahuluan (P.1)- Sejarah, Struktur & Komposisi Bumi (P.2)

    - Proses-Proses Geologi & Tektonik Lempeng (P.3-4)

    - Pengenalan Unsur, Mineral & Batuan (P.5-8) :

    - Unsur & Mineral

    - Batuan Beku- Batuan Sedimen

    - Batuan Metamorf 

    - Prinsip Stratigrafi, Paleontologi & Umur Geologi (P.9)

    - Pengenalan Struktur Geologi (P.10-11)

    - Pengenalan Hidrogeologi & Geomorfologi (P.12)- Pengenalan Kebencanaan Geologi (P.13)

    - Pengenalan Peta, Kompas, Navigasi dan PeralatanGeologi (P.14)

    - Kuliah Lapangan (Situasional)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    THE ROCK CYCLE

    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    The Rock Cycle - Plate Tectonics (Convergent

    Plate Boundary)

    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Locations of Magma Formation

    (Schmincke, 2004)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Magma is molten rock, usually rich in silica and

    containing dissolved gases. (Lava is magma on the

    Earth’s surface.

    Country rock, incidentally, is an accepted term for anyolder rock into which an igneous body intruded.

    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    3 model offormation of

    basaltic magmasfrom partialmelting ofperidotite(Schmincke, 2004)

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Magma Source: Partial Melting

    Mineral

    Hypothetical Solid Rock:Intermediate Composition

    A (Mafic)

    B (Int)

    C (Felsic)

    Melting

    Temp

    1200°C

    1000°C

    800°C

    Temperature = 500°C

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Mineral

    A (Mafic)

    B (Int)

    C (Felsic)

    Melting

    Temp

    1200°C

    1000°C

    800°C

    Temperature = 900°C Magma

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Mineral

    A (Mafic)

    B (Int)

    C (Felsic)

    Melting

    Temp

    1200°C

    1000°C

    800°C

    Temperature = 900°C

    Magma

    Magma Separates Felsic

    Remaining Rock: More Mafic

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Composition: Magma Source

    Mafic Intermediate Felsic

    Source: Partial Melting of ultramafic mantle at

    Divergent Zones and…

    Ultramafic mantle

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Mafic Intermediate Felsic

    Source: Partial Melting of ultramafic mantle at

    Divergent Zones and … Hot Spots

    ..... Composition: Magma Source

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Mafic Intermediate Felsic

    Source: Partial Melting of mantle, ocean crust and continent at

    Subduction Zones

    ...... Composition: Magma Source

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Mafic Intermediate Felsic

    Source: Partial melting felsic continent above

    Hot Spots & Subduction Zones

    ...... Composition: Magma Source

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    The Origin of Magma at Spreading Ridges

    and Subduction Zones

    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Hot Spot and the Origin of Magma

    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    MAGMATIC DIFFERENTIATION

    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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     Assimilation and Magma Mixing

    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Magma Mixing

    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    ROCK AND MINERAL TYPES

    • Examples of Igneous Rocks and their constituent

    minerals :

    Basalt, Gabbro, Rhyolite, Granite

    • Basalt and Gabbro differ not in composition, but in

    crystallinity; likewise Rhyolite and Granite.

    • Basalt and Gabbro differ in relative composition, of the

    five major constituents above, from Rhyolite and Granite.

    • Basalt and Rhyolite have small crystals because they are

    erupted by volcanoes and cool rapidly from the moltenstate.

    • Gabbro and Granite have large crystals because they

    cool slowly from the molten state, underground.Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Igneous MineralsMineral Properties

    Olivine Green to yellow-green; vitreous; fractures;

    small, equidimensional grains

    Plagioclase Usually white or gray;

    2 cleavages at 90°;

    elongate grains; striations sometimes visible

    Pyroxene Greenish black or brow nish black;rather dull luster;

     blocky grains

    Amphibole Black with shiny, splinter y appearance;

    two cleavages at 60° and 120°;elongate grains

    Biotite Shiny, black sheets;

    one perfect cleavage

    Orthoclase Usually white or pin k;

    2 cleavages at 90°;equidimensional grains

    Muscovite Shiny, silvery sheets;

    one perfect cleavage

    Quartz Colorless to gray;vitreous with conchoidal fracture;irregular grains in intrusive rocks;

    equidimensional phenocrysts in extrusive rocks

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    28

    Types of Minerals

    • Essential – Minerals which must be

    present in order for a rock to be classified

    with a certain name

    •  Accessory – Minerals need not bepresent in a rock, but which may be

    present in small amounts

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Compositional Terms for Igneous Rocks

    Felsic: feldspar + silica

    ~55-70% silica, K-feldspar > 1/3 of feldspars present

    light-colored silicate minerals — Continental crust

    Intermediate: between felsic and mafic

    ~55-65% silica, plag > 2/3 of feldspars present

    Na-rich plag predominates over Ca-rich plag

    Mafic: magnesium + ferric iron

    ~45-50% silica; Ca-rich plag dominant feldspar 

    dark silicate minerals — Oceanic crust

    Ultramafic: >90% mafic minerals, silica < 45%, few or no

    feldspars Mantle-derived

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Composition of Igneous Rocks

    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Best, 2003

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Textural Classification of Igneous Rocks

    Phaneritic: crystals visible with naked eye

    Plutonic or intrusive rocks

     Aphanitic: crystal too small for naked eye

    Volcanic or extrusive rocks

    Porphyritic: two different, dominant grain sizes

    Large xtals = phenocrysts; small xtals =

    groundmassFragmental: composed of disagregated igneous

    material Pyroclastic rocksSetijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Igneous Rock Textures

    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    35

    Porphyritic Size Distribution

    • Porphyritic - bimodal size distribution,with large grains surrounded by numeroussmall grains or glass

    • Phenocrysts - Large crystals formed byrelatively slow cooling below the earth’ssurface

    • Groundmass - Small crystals or glass,formed by more rapid cooling

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Textural Classification of Igneous Rocks

    Pegmatitic: very large xtals (cm to 10s of cm); i.e., slowlycooled

    Forms veins or layers within plutonic body

    Glassy: non-crystalline; cools very fast (e.g., obsidian)Volcanic rocks

    Vesicular: vesicles (holes, pores, cavities) form as gasesexpand

    Volcanic rocks

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Igneous Textures - Crystalline

    Coarse Grained Fine Grained

    Phaneritic Aphanitic

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Igneous Textures - Crystalline

    Porphyritic

    Phenocrysts

    Groundmass

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Glassy

    Vesicular

    Igneous Textures - Crystalline

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Igneous Textures - Pyroclastic/Fragmental

    Made of rock fragments

    rather than crystals

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Types of Igneous Rocks

    GraniteDioriteGabbro

    RhyoliteAndesiteBasalt Dacite

    GranodioriteMafic Intermediate Felsic

       F   i  n  e

       C

      o  a  r  s  e

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Ultramafic Rock - Dunite

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Schematic block diagram of some intrusive bodies.

    Bentuk Tubuh Batuan Beku (intrusif)

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Monroe & Wicander, 2009

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Massive Intrusive Bodies:

    Batholiths, Stocks, and Laccoliths

    BATHOLITHS. By far the largest intrusive igneous bodies

    are batholiths(bathos = depth, lithos = stone). Batholiths

    occur as mammoth linear structures several hundreds of

    kilometers long and up to 100 kilometers wide.

    STOCKS. By definition, a plutonic body must have a

    surface exposure greater than

    100 square kilometers (40 square miles) to be considered

    a batholith. Smaller plutons of this type are termed stocks.LACCOLITHS.

    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Lutgens, et al. (2012)

    Batholiths

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Tablular Intrusive Bodies: Dikes and Sills

    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Lutgens, et al. (2012)

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Carlson, et al. 2011

    Xenoliths, fragments of rock that are distinct from the body of igneous

    rocks in which they are enclosed.

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    Carlson, et al. 2011

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

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    1. Klasifikasi Batuan Piroklastik

    (a) Based on type of material. After Pettijohn (1975) Sedimentary Rocks, Harper & Row, and

    Schmid (1981) Geology, 9, 40-43. (b) Based on the size of the material. After Fisher (1966)

    Earth Sci. Rev., 1, 287-298.Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

    U i i k li

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    Best, 2003

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

    Q

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    2.A. Klasifikasi Batuan Beku

    Fanerit yang Baku adalah

    Klasi fikasi QAPF dari IUGS

    (Streckeisen, 1976)

    A classification of the phaneritic igneous rocks. a.

    Phaneritic rocks with more than 10% (quartz + feldspar +

    feldspathoids). After IUGS.

    Syarat:

    1.Batuan harus mengandung minimal

    total mineral Plagioklas, Ortoklas dan

    Kuarsa (atau Feldspatoid) minimal 10%

    2.Jumlah mineral-mineral tersebut

    dinormalisasi ke 100%

    Quartz-richGranitoid

    9090

    6060

    2020 Alkali Fs.Quartz Syenite

    QuartzSyenite

    QuartzMonzonite

    Quartz

    Monzodiorite

    Syenite Monzonite Monzodiorite

    (Foid)-bearingSyenite

    5

    10 35 65

    (Foid)-bearingMonzonite

    (Foid)-bearingMonzodiorite

    90

     Alkali Fs.

    Syenite

    (Foid)-bearing Alkali Fs. Syenite

    10

    (Foid)Monzosyenite

     (     F     o   i     d       )     S    

      y    e   n   i     t    e   

    (Foid)Monzodiorite

         (       F   o     i    d      )       G

       a     b     b    r   o

    Qtz. Diorite/Qtz. Gabbro

    5

    10

    Diorite/Gabbro/ Anorthosite

    (Foid)-bearingDiorite/Gabbro

    60

    (Foid)olites

    Quartzolite

    Granite Grano-diorite

    T     o   n   a   l     i     t    e   

         A      l      k

        a      l      i      F

        e      l    d    s    p    a    r     G

        r    a    n      i     t    e

    Q

     A P

    F

    60

    2. Klasifikasi Batuan Plutonik

    Setijadji (2011) - Slide

    U i it B k B lit

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    Best, 2003

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

    2 B Kl ifik i IUGS t k B t B k F it

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    A classification of the phaneritic igneous rocks.

    b. Gabbroic rocks. c. Ultramafic rocks. AfterIUGS.

    Plagioclase

    OlivinePyroxene

        G   a    b    b   r   o

      T     r    o   

    c   t     o   

    l     i     t     e   Olivine gabbro

    Plagioclase-bearing ultramafic rocks

    90

    (b)

     Anorthosite

    OlivineOlivine

    ClinopyroxeneClinopyroxeneOrthopyroxeneOrthopyroxene

    LherzoliteLherzolite

        H  a   r   z    b

       u   r   g     i   t

      e

    W    e  h   

    r   l   i   t   e  

    Websterite

    OrthopyroxeniteOrthopyroxenite

    ClinopyroxeniteClinopyroxenite

    Olivine Websterite

    PeridotitesPeridotites

    PyroxenitesPyroxenites

    90

    40

    10

    10

    DuniteDunite

    (c)

    Batuan Mafik

    (Gabbroit)

    Batuan Ultramafik

    2. B. Klasifikasi IUGS untuk Batuan Beku Fanerit

    yang Mafik (b) dan Ultramafik (c)

    Setijadji (2011) - Slide

    Q

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    A classification and nomenclature of volcanic

    rocks. After IUGS.

    (foid)-bearing  Trachyte

    (foid)-bearing  Latite

    (foid)-bearing Andesite/Basalt

    (Foid)ites

    10

    60 60

    35 65

    10

    20 20

    6060

    F

     A P

    Q

    Rhyolite Dacite

    Trachyte Latite Andesite/Basalt

    Phonolite Tephrite

    3. Klasifikasi Batuan Beku Afanit (Vulkanik) yang Bakuadalah dari IUGS (Streckeisen,1976)

    Syarat:

    1.Batuan harus mengandung minimal

    total mineral Plagioklas, Ortoklas dan

    Kuarsa (atau Feldspatoid) minimal

    10%2.Jumlah mineral-mineral tersebut

    dinormalisasi ke 100%

    Setijadji (2011) - Slide

    U i e it B k Belit

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    Klasifikasi Batuan Vulkanik

    • Secara umum, penamaan batuanvulkanik non-piroklastik adalahberdasarkan komposisi mineral penyusunnya, dengan menggunakanklasifikasi QAPF yang disusunoleh Streckeisen (1967).

    • Namun, jika prosentasi modal mineral yang disyaratkan untukklasifikasi tersebut tidak dipenuhi, maka klasifikasi tersebuttidak bisadigunakan. Kandungan mineral sering tidak bisa ditentukan secara

    prosentase modal karena kehadiranmineral berukuran halus ataukarena kehadiranmaterial gelasan.

    • Untuk mengatasi hal tersebut , maka IUGS Subcommission on theSystematics of Igneous Rocks membuat rekomendasi untukmembuatberdasarkan diagram Total Alkali – Silika atau dikenal sebagai diagram TAS (Le Bass dkk., 1986).

    • Klasifikasi ini dipakai jika 1) analisa kimia yang valid diperoleh, 2)analisis modal mineral tidak diperoleh dan 3) tidak berlaku untuk batuanvulkanik piroklastik.

    Setijadji (2011) - Slide

    Universitas Bangka Belitung Jurusan Teknik Pertambangan 

    3 B Kl ifik i TAS (T t l Alk li Sili ) t k

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    3.B. Klasifikasi TAS (Total Alkali Silica) untuk

    Batuan Vulkanik

    A chemical classification of volcanics based on total alkalis vs. silica. After Le Baset al. (1986) J.

    Petrol., 27, 745-750. Oxford University Press. Setijadji (2011) - Slide

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    COMPOSITION (Minerals Present)

    Ultramafic

    Olivine(Pyroxene) 

    Mafic

    Ca-Plagioclase

    Pyroxene

    Olivine 

    Intermediate

     Na-Plagioclase

    Amphibole

    Pyroxene

    Biotite 

    Intermediate

     Na-PlagioclaseAmphibole

    Quartz

    Biotite 

    Felsic

    QuartzOrthoclase

    Biotite

     Na-Plagioclase 

    Coarse-

    grained*

    DUNITE GABBRO DIORITE GRANODIORITE GRANITE

    Fine-

    grained*BASALT ANDESITE DACITE RHYOLITE

    Glassy OBSIDIAN

    Vesicular SCORIA PUMICE   T   E   X   T   U   R   E   S

    Fragmental

    (Pyroclastic)TUFF

    *Some igneous rocks have a porphyritic texture. If a rock has 2 grain sizes, the rock is named after

    the smaller grain size and the word porphyritic is added as an adjective.For example, if a rock is

     predominantly fine-grained and mafic, it would be a basalt. If phenocrysts are present in the fine-

    grained matrix, this rock would be called a porphyritic basalt.

    Universitas Bangka Belitung J T k ik P t b

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    Lutgens, et al. (2012)

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    Universitas Bangka Belitung J T k ik P t b

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    Lutgens, et al. (2012)

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    Universitas Bangka Belitung J s Tek ik Pe t b g

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    Terima Kasih

    Universitas Bangka Belitung Jurusan Teknik Pertambangan