Post on 01-Oct-2021
ETROLO
U NA P
[TGS7404]
Dr. Hill. Gendoet Hartono
Semester 7, 2017-2018
2 SKS teori
GI BA
GI
T UAN
PENDAHULUAN 1X
Berisi tentang latarbelakang, bumi, batuan beku dan
batuan gunung api, dan kedudukan di bidang geologi
TATAAN TEKTONIK 2X
Berisi tentang tektonik global, regim tektonik, dan
peranannya dalam magmatisme dan volkanisme
GENERASI MAGMA 2X
Berisi tentang magmatisme, diagram fase
KLASIFIKASI 2X
Klasifikasi magma atau afinitas magma
Rock Forming Mineral 1X
Kimia Mineral Pembentuk Batuan 1X
Petrologi Batuan Intrusi Dangkal 2X
Petrologi Batuan Ekstrusi 2X
Alterasi Batuan Gunung Api 1X
(Hartono, 2010)
BATUAN GUNUNG API
•BATUAN YANG TERBENTUK SEBAGAI HASIL AKTIVITAS GUNUNG API, BAIK LANGSUNG MAUPUN TIDAK LANGSUNG
• LANGSUNG: HASIL ERUPSI MEMBEKU/MENGENDAP INSITU
• TIDAK LANGSUNG: SUDAH MENGALAMI PEROMBAKAN/ DEFORMASI
KELOMPOK UTAMA BATUAN GUNUNG API
• LAVA KOHEREN (INTRUSI DANGKAL & BATUAN BEKU LUAR)
•BATUAN KLASTIKA GUNUNG API
CIRI-CIRI BATUAN GUNUNG API
• TEKSTUR HIPOKRISTALIN -GELAS/HOLOHEALIN
•STRUKTUR MENCERMINKAN PENDINGINAN SANGAT CEPAT (embayment, glass inclusions, skeletal, etc.)
•KOMPOSISI SELALU MENGANDUNG GELAS
Hypocrystalline is a textural term describing an igneous
rock consisting of a mixture of glass and crystals where
the ratio of crystals to glass is greater than 3:5.
Porphyritic texture is an igneous rock texture in which
large crystals are set in a finer-grained or glassy
groundmass. Porphyritic textures occur in coarse,
medium and fine-grained igneous rocks. Usually the
larger crystals, known as phenocrysts, formed earlier in
the crystallisation sequence of the magma. A porphyritic
texture in which there is a continuous variation in crystal
size is termed seriate. Hypabyssal rocks with porphyritic
textures are sometimes termed porphyrys.
Hypocrystalline Texture
Porphyritic textures develop when conditions during
cooling of a magma change relatively quickly. The
earlier formed minerals will have formed slowly and
remain as large crystals, whereas, sudden cooling
causes the rapid crystallization of the remainder of the
melt into a fine grained (aphanitic) matrix. The result is
an aphanitic rock with some larger crystals (phenocrysts)
imbedded within its matrix. Porphyritic texture also
occurs when magma crystallizes below a volcano but is
erupted before completing crystallization thus forcing
the remaining lava to crystallize more rapidly with much
smaller crystals.
DASAR PENAMAAN
•DESKRIPSI NAMA (SECARA DESKRIPSI)
•DESKRIPSI GENESA NAMA (SECARA GENESA)
•KOMBINASI NAMA SECARA DESKRIPSI & GENESA
LINGKUP PENAMAAN
•MEGASKOPIK CONTOH SETANGAN
•MEGASKOPIK DI LAPANGAN
•MIKROSKOPIK
•KIMIAWI
PARAMETER DESKRIPSI
•WARNA
• TEKSTUR (BENTUK & UKURAN BUTIR/KRISTAL, KEMAS, SORTASI)
•STRUKTUR (PENDINGINAN CEPAT & PENGENDAPAN)
•KOMPOSISI (MINERAL, BATUAN)
PARAMETER GENESA
•SUMBER (ERUPSI GUNUNG API)
•PROSES (MEKANISME PEMBEKUAN/ PENGENDAPAN)
•UMUR (PEMBEKUAN/ PENGENDAPAN)
• LINGKUNGAN (PEMBEKUAN/ PENGENDAPAN
PENAMAAN DESKRIPTIF MINERALOGI LAVA KOHEREN
WARNA gelap/ hitam abu-abu
TEKSTUR afanit porfiri
STRUKTUR masif -
skoria
masif
KOMPOSISI - fenok: plg &
hbl, msdsr
afanit
NAMA Basal Andesit
PENAMAAN DESKRIPTIF SECARA KIMIA
NAMA BATUAN % Berat SiO2Basal 45 - 52
Andesit basal 53 – 57
Andesit 58 – 63
Dasit 64 – 68
Riolit 69 - 75
BASALT TYPES-MAJOR ELEMENT VARIATION
SILICA SATURATION
Silica-oversaturated: rocks contain Q (quartz or its polymorphs-
cristobalite and tridymite), such as granite
Silica-saturated: rocks contain Hy, but no Q, Ne, or Ol (no quartz,
feldspathoids, or olivine), such as diorite and andesite
Silica-undersaturated: rocks contain Ol and possibly Ne (Mg-
olivine and possibly feldspathoids, analcime, perovskite, melanite
garnet, and melilite), such as nepheline syenite
Presenter’s notes: Igneous features inthe Bight Basin are typical of intrusionsobserved elsewhere; they areexpressed as very high-amplitudeanomalies, which are typicallydiscordant to concordant with encasingstrata and are underlain by velocitypull-ups that attest to theiracoustically-fast properties. Intrusiveigneous features in the Bight Basin areoverlain by a field of genetically-related extrusive igneous features,including large features interpreted asvolcanoes and smaller featuresinterpreted as hydrothermal vents.Intrusive igneous features are alsoassociated with folding of overlyingstrata; we shall return to the genesisand importance of these folds later inthe presentation.
Presenter’s notes: Thisfigure highlights the impactthat igneous systems canhave on petroleum systemdevelopment in sedimentarybasins.This figure principallyhighlightscompartmentalisation ofbasin by vertically- andlaterally-extensive intrusions;furthermore, in the upperpart of the basin, the impactof intrusions on trapdevelopment is highlighted.A secondary aim of thispresentation, which wasnoted in anotherpresentation, is how seismicreflection data, in particularhigh-quality, three-dimensional data, can helpus understand igneousprocesses in a more generalsense.
PENAMAAN GENETIK LAVA KOHEREN
• INTRUSI DANGKAL: RETAS (DIKE), SILL, LEHER GUNUNG API
•BATUAN EKSTRUSI: KUBAH LAVA, ALIRAN LAVA
CIRI DESKRIPTIF INTRUSI DANGKAL
•BENTUK GEOMETRI
•EFEK KONTAK (WARNA, TEKSTUR, STRUKTUR & KOMPOSISI)