DAFTAR ISI
HALAMAN JUDUL...........................................................................................
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HALAMAN PENGESAHAN .............................................................................
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HALAMAN PERNYATAAN ............................................................................ iii KATA PENGANTAR ........................................................................................ iv DAFTAR ISI ....................................................................................................... vi DAFTAR GAMBAR .......................................................................................... viii DAFTAR TABEL ............................................................................................... xi INTISARI............................................................................................................ xii ABSTRACT ........................................................................................................ xiii BAB I PENDAHULUAN ................................................................................... 1 I.1 Latar Belakang .......................................................................................... 1 I.2 Rumusan Masalah ..................................................................................... 3 I.3 Tujuan Penelitian ...................................................................................... 3 I.4 Batasan Masalah ....................................................................................... 4 I.5 Lokasi Penelitian ....................................................................................... 4 I.6 Manfaat Penelitian .................................................................................... 5 I.7 Peneliti Terdahulu ..................................................................................... 5 BAB II TINJAUAN PUSTAKA......................................................................... 7 II.1 Geologi Regional Daerah Penelitian ....................................................... 7 II.1.1 Stratigrafi Regional .......................................................................... 8 II.1.2 Struktur Geologi Regional ............................................................... 11 II.2 Dasar Teori .............................................................................................. 12 II.2.1 Mineralogi dan Tipe Deposit Mangan ............................................. 12 II.2.1.1 Mineralogi ................................................................................ 12 II.2.1.2 Tipe Deposit Mangan ............................................................... 15 II.2.2 Konsep Dasar Metode Induce Polarization ..................................... 18 vi
II.2.2.1 Fenomena Penyebab Efek IP.................................................... 18 II.2.2.2 Rangkaian Ekuivalen................................................................ 20 II.2.2.3 Sumber – Sumber Efek Polarisasi pada Batuan ....................... 21 II.2.2.4 Prinsip Pengukuran .................................................................. 25 II.2.2.5 Metode Pengukuran Kawasan Waktu (Time Domain) ............. 26 II.2.2.6 Metode Pengukuran Kawasan Frekuensi ................................. 28 II.2.3 Konsep Dasar Sistem Informasi Geografis ............................................... 30 II.2.3.1 Definisi Sistem Informasi Geografis............................................. 30 II.2.3.2 Data Management System (DBMS) .............................................. 31 II.2.3.3 Analisis dan Pemodelan Data Spasial ........................................... 35 II.2.4 Hipotesis .................................................................................................... 41 BAB III METODE PENELITIAN...................................................................... 43 III.1 Metode Penelitian ................................................................................... 43 III.1.1 Pengolahan Data Induced Polarization ........................................... 43 III.1.2 Integrasi Data dengan Sistem Informasi Geografis ........................ 43 III.2 Diagram Alir Penelitian.......................................................................... 44 BAB IV HASIL DAN PEMBAHASAN ............................................................ 46 IV.1 Pengutaraan Data ................................................................................... 46 IV.2 Hasil dan Pembahasan............................................................................ 49 IV.2.1 Data Model Integrasi Data Polarization dan Geologi..................... 49 IV.2.2 Hasil Interpretasi Data Geologi ...................................................... 52 IV.2.3 Pemodelan Data IP dan Geologi ke dalam Sistem Informasi Geografis ........................................................................................ 69 BAB V KESIMPULAN DAN SARAN.............................................................. 107 V.1 Kesimpulan ......................................................................................... 107 V.2 Saran ................................................................................................... 108 DAFTAR PUSTAKA ......................................................................................... 109 LAMPIRAN ........................................................................................................ 112
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DAFTAR GAMBAR
Gambar
Halaman
1.1 Peta lokasi penelitian ................................................................................ 4 2.1. Peta geologi regional lokasi penelitian (modifikasi dari Silitonga dan Kastawa,1995) .................................................................................. 7 2.2. Urutan stratigrafi (modifikasi Silitonga dan Kastawa,1995).................. 9 2.3. Distribusi ion dalam pori (modifikasi Slater dan Lesmes) ...................... 18 2.4. Contoh batuan yang mengandung mineral (Reynolds,1997) .................. 19 2.5. Grafik peluruhan potensial (Reynolds,1997) .......................................... 19 2.6. Rangkaian ekuivalen yang digunakan sebagai model untuk menggambarkan efek polarisasi terimbas (Reynolds,1997) .......... 20 2.7. Model penampang melintang batuan (Reynolds,1997) ........................... 22 2.8. Gerakan ion – ion pada pori – pori batuan (modifikasi Telford, 1990) .. 23 2.9.Proses terjadinya polarisasi membran pada pori – pori batuan (Reynolds,1997) ............................................................................... 24 2.10.Susunan elektroda konfigurasi dipol – dipol dan plotting point (Milsom, 2003) ................................................................................ 25 2.11.Grafik arus listrik dan potensial dalam kawasan waktu (modifikasi Telford, 1990) ................................................................................. 27 2.12.Tahapan pemetaan potensi mineral dengan SIG (modifikasi Bonham – Carter, 1994).................................................................................. 31 2.13.Data model dari fenomena ke dalam database, dan dari model digital kartografis dan peta analog sebagai visualisasi (Kanz, 2010) .......... 32 2.14.Alur data geofisika (modifikasi Tedla, 2005) ........................................ 34 2.15.Contoh organisasi data geofisika dan geologi (modifikasi Tedla, 2005) ................................................................................................ 35 2.16.Perbedaan struktur data tipe vektor dan raster (Buckley, 1997) ............ 38 2.17.(a)Histogram data distribusi normal, (b) Histogram data tidak terdistribusi normal (Krivoruchko, 2012) ........................................ 40 3.1 Diagram alir penelitian ............................................................................. 45 viii
4.1 Peta lintasan IP dan geologi .................................................................... 48 4.2 Struktur geodatabase penelitian dan RS .................................................. 50 4.3 Skema model data penelitian ................................................................... 51 4.4 (a)Titik pengamatan Mn 10, (b) Titik pengamatan Mn 20 ...................... 52 4.5 Singkapan mangan ................................................................................... 53 4.6 Peta unit litologi daerah penelitian ........................................................... 60 4.7 Pseudosection IP untuk line 1(a), line 2(b), line 3(c), dan line 4(d) ........ 65 4.8 Pseudosection IP untuk line 5(a), line 6(b),line 7(c),dan line8 (d) ......... 66 4.9 Pseudosection IP untuk line 9(a), line 10(b) , line11(c),dan line12(d) ... 67 4.10 Pseudosection IP untuk line13(a), line14(c), dan line15(d) .................. 68 4.11 (a) Garis lintasan IP, (b)Titik lintasan IP .............................................. 69 4.12 (a) Histogram nilai resistivity dan (b) Histogram nilai resistivity dengan transformasi ....................................................................... 72 4.13 (a) Histogram nilai chargeability dan (b) Histogram nilai chargeability dengan transformasi ................................................. 73 4.14 (a) Variogram nilai resistivity dan (b) Variogram nilai chargeability .......................................................................................................... 74 4.15 Peta surface resistivity untuk n 1 (a), n 2 (b), n 3 (c), dan n 4 (d) ......... 75 4.16 Peta surface resistivity untuk n 5 (a), n 6 (b), n 7 (c), dan n 8 (d) ......... 76 4.17 Peta surface resistivity untuk n 9 (a), n 10 (b), n 11 (c) ........................ 77 4.18 Peta surface chargeability untuk n 1 (a), n 1 (b), n 3(c), dan n 4 (d) .... 78 4.19 Peta surface chargeability untuk n 5 (a), n 6 (b), n 7(c), dan n 8 (d) .... 79 4.20 Peta surface chargeability untuk n 9 (a), n 10 (b), n 11(c) ................... 80 4.21 Peta reclassify resistivity untuk n1 (a), n2 (b), n3 (c), dan n4 (d) ......... 84 4.22 Peta reclassify resistivity untuk n5 (a), 6 (b), n7 (c), dan n8 (d) .......... 85 ix
4.23 Peta reclassify resistivity untuk n9 (a), n 10 (b), n11 (c) ....................... 86 4.24 Peta reclassify chargeability untuk n1(a), n2 (b), n3 (c), dan n4 (d) .... 87 4.25 Peta reclassify chargeability untuk n5(a), 6(b), n7(c), dan n8(d) ........ 88 4.26 Peta reclassify chargeability untuk n9 (a), n 10 (b), n11 (c) ................. 89 4.27 Peta indikasi potensi mangan kedalaman 1,71m .................................... 90 4.28 Peta indikasi potensi mangan kedalaman 5,21m .................................... 91 4.29 Peta indikasi potensi mangan kedalaman 8,72m .................................... 92 4.30 Peta indikasi potensi mangan kedalaman 12,86m .................................. 93 4.31 Peta indikasi potensi mangan kedalaman 17m ....................................... 94 4.32 Peta indikasi potensi mangan kedalaman 22m ....................................... 95 4.33 Peta indikasi potensi mangan kedalaman 27m ....................................... 96 4.34 Peta indikasi potensi mangan kedalaman 33,1m .................................... 97 4.35 Peta indikasi potensi mangan kedalaman 39,2m .................................... 98 4.36 Peta indikasi potensi mangan kedalaman 46,2m .................................... 99 4.37 Peta indikasi potensi mangan kedalaman 53,9m ....................................100 4.38 Gambar IP integration tools ...................................................................101 4.39 Model builder conversion tools ..............................................................102 4.40 Tampilan conversion tools .....................................................................104 4.41 Model builder modeling tools.................................................................105 4.42 Tampilan builder modeling tools ...........................................................106
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DAFTAR TABEL
Tabel
Halaman
2.1. Mineralogi dari mangan (Jacoby, 1983).................................................. 14 2.2. Komposisi kimia dari nodul mangan (Agarwal et al, 2012) ................... 16 2.3. Chargeability mineral sulfida (Telford,1990) ......................................... 28 2.4. Percent frequency efect batuan (Telford,1990) ....................................... 29 2.5. Harga metal factor untuk masing – masing batuan (Telford,1990) ........ 30 2.6. Tipe data dalam SIG (Bonham-Carter, 1994) ......................................... 36 2.7. Metode analisis spasial multi peta (Bonham-Carter, 1994) .................... 39 4.1. Titik pengamatan lapangan ..................................................................... 54 4.2. Nilai kedalaman tiap n ............................................................................. 70 4.3. Nilai resistivity dan chargeability pada titik bor 1 dan 2 untuk kedalaman 1,71 m dan 5 m............................................................... 82
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