STUDI GEOKIMIA UNSUR UTAMA BATUAN GUNUNGAPI BATUR KABUPATEN BANGLI, PROPINSI BALI.
DAFTAR ISI
Halaman
SARI .................................................................................................................
i
ABSTRACT.......................................................................................................
ii
KATA PENGANTAR ......................................................................................
iii
DAFTAR ISI ....................................................................................................
vi
DAFTAR TABEL ...........................................................................................
ix
DAFTAR GAMBAR .......................................................................................
x
BAB I
PENDAHULUAN ............................................................................
1
1.1
LatarBelakangMasalah ....................................................................
1
1.2
BatasanMasalah ..............................................................................
1
1.3
MaksuddanTujuan...........................................................................
2
1.4
Lokasi Daerah Penelitian .................................................................
3
1.5 TahapanPenelitian ..............................................................................
3
BAB II
TATANAN GEOLOGI ....................................................................
5
2.1
TektonikRegional ............................................................................
5
2.2
GeologiGunungapi Regional ...........................................................
7
2.3
Stratigrafi Gunungapi Regional .......................................................
10
2.4Landasan Teori .............................................................................................
14
2.4.1 Magmatisma dan Petrografi .....................................................
14
BAB III METODE PENELITIAN ................................................................
22
3.1
Peralatandan Data ..........................................................................
22
3.2
Langkah – langkahPenelitian...........................................................
22
3.2.1 StudiPendahuluan ....................................................................
22
3.2.2 Pengamatan Data ....................................................................
22
3.2.3 AnalisisdanPengolahan Data ...................................................
23
3.2.3.1Analisis Petrografi .........................................................
23
3.2.3.2Analisis Kimia ..............................................................
24
3.2.3.2.1Klasifikasi Batuan Menurut Wilson (1989) .................
25
vi
3.2.3.2.2Klasifikasi Batuan Menurut Irvine dan Baragar(1971)
26
3.2.3.2.3Diagram Variasi Unsur Utama .......................................
33
3.2.3.2.4 Pembagian Jenis Magma Menurut Irvine dan
Baragar (1971) ..................................................
33
3.2.3.2.5Hubungan Zona Benioff dengan kedalaman magma
asal ....................................................................
34
3.2.3.2.6 Penentuan Magma Asal Menurut Pearce
(1977) ...............................................................
35
TahapPenyusunan Laporan .............................................................
36
BAB IV PEMBAHASAN ..............................................................................
37
3.3
4.1
PengamatanLapangan......................................................................
37
4.2
Petrografi ........................................................................................
43
4.3
Analisis Kimia Batuan ....................................................................
44
4.3.1 Klasifikasi Batuan Menurut Wilson (1989) ..............................
46
4.3.2 Klasifikasi Batuan Menurut Irvine & Baragar (1971) ...............
47
4.3.3 Diagram Variasi Unsur Utama .................................................
53
4.3.4 Pembagian Jenis Magma Menurut Irvine&Baragar (1971) .......
54
4.3.5 Hubungan Zona Benioff Dengan Kedalaman Magma Asal .......
56
4.3.6 Perhitungan Magma Asal Menurut Pearce (1977) ....................
58
KESIMPULAN ................................................................................
60
DAFTAR PUSTAKA .......................................................................................
62
BAB V
DAFTAR TABEL
vii
Tabel
Halaman
2.1
Legenda Peta Geologi Kaldera Gunungapi Batur ...............................
13
4.1
Komposisi Kimia Unsur Utama Gunungapi Batur ..............................
46
4.2
Nama Batuan Berdasarkan nilai SiO2 dan Alkali ................................
46
4.3
Jenis Batuan Berdasarkan Normatif Indeks Warna dan Normatif
Plagioklas ..........................................................................................
4.4
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-01) ...................................................................................
4.5
4.9
51
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-04) ...................................................................................
4.8
50
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-03) ...................................................................................
4.7
49
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-02) ...................................................................................
4.6
47
52
Jenis Magma Berdasarkan Perbandingan Alkali, Oksida Besi dan
Oksida Magnesium ............................................................................
55
Asal Magma Berdasarkan Kandungan MgO, FeO, Fe2O3, dan Al2O3 .
58
DAFTAR GAMBAR
viii
Gambar
Halaman
1.1
PetaLokasiGunungapi Batur ...............................................................
3
2.1
TektonikIndonesia (Katili, 1973) ........................................................
5
2.2
Penampang Pulau Bali .......................................................................
6
2.3
Peta Geologi Kaldera Gunungapi Batur (Sutawidjaja, 1992) ..............
9
2.4
Peta Geologi Dalam Kaldera Gunungapi Batur (Sutawidjaja, 1992) ...
9
2.5
Kristalisasi dan Settling......................................................................
16
2.6
Asimilasi Magma ...............................................................................
17
2.7
Differensiasi Magma ..........................................................................
18
2.8
Deret Bowen ......................................................................................
19
3.1
Diagram TAS (Wilson, 1989) ............................................................
26
3.2
Diagram Normatif Indeks Warna Serta Normatif Komposisi Mineral
Plagioklas(Irvine dan Baragar, 1971) ................................................
32
3.3
Diagram Jenis Magma (Irvine dan Baragar, 1971)..............................
33
3.4
Diagram Kedalaman Zona Benioff (Whitford & Nichols, 1973) .........
35
3.5
Diagram Penentuan Magma Asal (Pearce, 1977) ................................
36
4.1
Endapan Lava Songan ........................................................................
38
4.2
Endapan Lava 1849............................................................................
39
4.3
Endapan Lava 1888............................................................................
39
4.4
Endapan Lava 1904............................................................................
40
4.5
Endapan Lava 1905............................................................................
41
4.6
Endapan Lava 1926............................................................................
41
4.7
Endapan Lava 1963............................................................................
42
4.8
Endapan Lava 1968............................................................................
43
4.9
Peta Lokasi Contoh Batuan Terpilih Untuk Analisis Kimia ................
45
4.10
Pencantuman Sampel Pada Diagram TAS (Wilson, 1989) ..................
46
4.11
Pencantuman Sampel Pada Diagram Normatif Indeks Warna Serta
Normatif Komposisi Mineral Plagioklas (Irvine&Baragar, 1971) .......
48
4.12
Diagram Variasi Unsur Utama ...........................................................
53
4.13
Diagram Jenis Magma (Irvine dan Baragar, 1971)..............................
55
ix
4.14
Diagram Kedalaman Zona Benioff (Whitford & Nichols, 1973) .........
4.15
Pencantuman Sampel Pada Diagram Penentuan Magma Asal
Berdasarkan Kandungan Al2O3, Fe2O3, FeO dan MgO .......................
x
57
58
Halaman
SARI .................................................................................................................
i
ABSTRACT.......................................................................................................
ii
KATA PENGANTAR ......................................................................................
iii
DAFTAR ISI ....................................................................................................
vi
DAFTAR TABEL ...........................................................................................
ix
DAFTAR GAMBAR .......................................................................................
x
BAB I
PENDAHULUAN ............................................................................
1
1.1
LatarBelakangMasalah ....................................................................
1
1.2
BatasanMasalah ..............................................................................
1
1.3
MaksuddanTujuan...........................................................................
2
1.4
Lokasi Daerah Penelitian .................................................................
3
1.5 TahapanPenelitian ..............................................................................
3
BAB II
TATANAN GEOLOGI ....................................................................
5
2.1
TektonikRegional ............................................................................
5
2.2
GeologiGunungapi Regional ...........................................................
7
2.3
Stratigrafi Gunungapi Regional .......................................................
10
2.4Landasan Teori .............................................................................................
14
2.4.1 Magmatisma dan Petrografi .....................................................
14
BAB III METODE PENELITIAN ................................................................
22
3.1
Peralatandan Data ..........................................................................
22
3.2
Langkah – langkahPenelitian...........................................................
22
3.2.1 StudiPendahuluan ....................................................................
22
3.2.2 Pengamatan Data ....................................................................
22
3.2.3 AnalisisdanPengolahan Data ...................................................
23
3.2.3.1Analisis Petrografi .........................................................
23
3.2.3.2Analisis Kimia ..............................................................
24
3.2.3.2.1Klasifikasi Batuan Menurut Wilson (1989) .................
25
vi
3.2.3.2.2Klasifikasi Batuan Menurut Irvine dan Baragar(1971)
26
3.2.3.2.3Diagram Variasi Unsur Utama .......................................
33
3.2.3.2.4 Pembagian Jenis Magma Menurut Irvine dan
Baragar (1971) ..................................................
33
3.2.3.2.5Hubungan Zona Benioff dengan kedalaman magma
asal ....................................................................
34
3.2.3.2.6 Penentuan Magma Asal Menurut Pearce
(1977) ...............................................................
35
TahapPenyusunan Laporan .............................................................
36
BAB IV PEMBAHASAN ..............................................................................
37
3.3
4.1
PengamatanLapangan......................................................................
37
4.2
Petrografi ........................................................................................
43
4.3
Analisis Kimia Batuan ....................................................................
44
4.3.1 Klasifikasi Batuan Menurut Wilson (1989) ..............................
46
4.3.2 Klasifikasi Batuan Menurut Irvine & Baragar (1971) ...............
47
4.3.3 Diagram Variasi Unsur Utama .................................................
53
4.3.4 Pembagian Jenis Magma Menurut Irvine&Baragar (1971) .......
54
4.3.5 Hubungan Zona Benioff Dengan Kedalaman Magma Asal .......
56
4.3.6 Perhitungan Magma Asal Menurut Pearce (1977) ....................
58
KESIMPULAN ................................................................................
60
DAFTAR PUSTAKA .......................................................................................
62
BAB V
DAFTAR TABEL
vii
Tabel
Halaman
2.1
Legenda Peta Geologi Kaldera Gunungapi Batur ...............................
13
4.1
Komposisi Kimia Unsur Utama Gunungapi Batur ..............................
46
4.2
Nama Batuan Berdasarkan nilai SiO2 dan Alkali ................................
46
4.3
Jenis Batuan Berdasarkan Normatif Indeks Warna dan Normatif
Plagioklas ..........................................................................................
4.4
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-01) ...................................................................................
4.5
4.9
51
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-04) ...................................................................................
4.8
50
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-03) ...................................................................................
4.7
49
Perhitungan Normatif Komposisi Mineral Berdasarkan Metoda
CIPW (RG-02) ...................................................................................
4.6
47
52
Jenis Magma Berdasarkan Perbandingan Alkali, Oksida Besi dan
Oksida Magnesium ............................................................................
55
Asal Magma Berdasarkan Kandungan MgO, FeO, Fe2O3, dan Al2O3 .
58
DAFTAR GAMBAR
viii
Gambar
Halaman
1.1
PetaLokasiGunungapi Batur ...............................................................
3
2.1
TektonikIndonesia (Katili, 1973) ........................................................
5
2.2
Penampang Pulau Bali .......................................................................
6
2.3
Peta Geologi Kaldera Gunungapi Batur (Sutawidjaja, 1992) ..............
9
2.4
Peta Geologi Dalam Kaldera Gunungapi Batur (Sutawidjaja, 1992) ...
9
2.5
Kristalisasi dan Settling......................................................................
16
2.6
Asimilasi Magma ...............................................................................
17
2.7
Differensiasi Magma ..........................................................................
18
2.8
Deret Bowen ......................................................................................
19
3.1
Diagram TAS (Wilson, 1989) ............................................................
26
3.2
Diagram Normatif Indeks Warna Serta Normatif Komposisi Mineral
Plagioklas(Irvine dan Baragar, 1971) ................................................
32
3.3
Diagram Jenis Magma (Irvine dan Baragar, 1971)..............................
33
3.4
Diagram Kedalaman Zona Benioff (Whitford & Nichols, 1973) .........
35
3.5
Diagram Penentuan Magma Asal (Pearce, 1977) ................................
36
4.1
Endapan Lava Songan ........................................................................
38
4.2
Endapan Lava 1849............................................................................
39
4.3
Endapan Lava 1888............................................................................
39
4.4
Endapan Lava 1904............................................................................
40
4.5
Endapan Lava 1905............................................................................
41
4.6
Endapan Lava 1926............................................................................
41
4.7
Endapan Lava 1963............................................................................
42
4.8
Endapan Lava 1968............................................................................
43
4.9
Peta Lokasi Contoh Batuan Terpilih Untuk Analisis Kimia ................
45
4.10
Pencantuman Sampel Pada Diagram TAS (Wilson, 1989) ..................
46
4.11
Pencantuman Sampel Pada Diagram Normatif Indeks Warna Serta
Normatif Komposisi Mineral Plagioklas (Irvine&Baragar, 1971) .......
48
4.12
Diagram Variasi Unsur Utama ...........................................................
53
4.13
Diagram Jenis Magma (Irvine dan Baragar, 1971)..............................
55
ix
4.14
Diagram Kedalaman Zona Benioff (Whitford & Nichols, 1973) .........
4.15
Pencantuman Sampel Pada Diagram Penentuan Magma Asal
Berdasarkan Kandungan Al2O3, Fe2O3, FeO dan MgO .......................
x
57
58