petrologi [TGS7208] 2 SKS teori 1 SKS praktikum Semester 2, 2017-2018 by: hill. gendoet hartono

UTS UAS Siklus Batuan, Kontrak Kuliah, Kelulusan, & Praktikum Magma, Diferensiasi, Viskositas, Gas dan Komposisi Batuan Beku, Intrusi Dalam & Karakteristiknya Batuan Gunung Api, Intrusi Dangkal & Karakteristiknya Batuan Gunung Api, Lelehan, Letusan & Karakternya Klasifikasi Batuan Beku & Gunung Api Batuan Alterasi UTS Batuan Sedimen, Jenis & Proses Pembentukan Batuan Sedimen Silisiklastika Batuan Sedimen Karbonat Klasifikasi Batuan Sedimen Batuan Metamorf, Jenis & Proses Pembentukan Batuan Metamorf Derajat Rendah, Menengah & Tinggi Klasifikasi Batuan Metamorf UAS

Minerals to Rocks: Major Rock Groups

Igneous Rocks: Approximately 90% of the earth's crust is composed of igneous rocks but their great abundance is hidden on the earth's surface by a relatively thin layer of sedimentary and metamorphic rocks. "Igneous rocks" are formed by cooling and solidification of magma. 'Magma' is a hot viscous, siliceous melt containing water vapor and gases. It comes from great depth below the earth's surface. It is composed mainly of O, Si, Al, Fe, Ca, Mg, Na and K. When magma comes out upon the earth's surface, it loses its gases. Such magma is called "lava".

Intrusive Rocks: Intrusive rocks are formed when magma crystallizes beneath the earth's surface. Depending on the depth of formation, intrusive rocks are divided into two groups: (1) plutonic rocks, and (2) hypabyssal rocks. Plutonic Rocks - Rocks crystallized at great depths are called "plutonic rocks". A magma which is deeply buried in the earth's crust. Cools slowly with the retention of the volatiles. As a result the mineral constituents crystallizing from it have time to grow to considerable size giving the rock a coarse grained texture. Hypabyssal Rocks-hypabyssal rocks are formed when magma solidifies close to the earth's surface. These rocks occur as injections within the country rocks. Their textures are usually finer grained than those of plutonic rocks but coarser than those of volcanic rocks. The hypabyssal rocks commonly show porphyritic texture.

BATUAN BEKU PLUTONIK/ INTRUSI DALAM

Definition of plutonic rock : an igneous rock (as granite) of holocrystalline granular texture regarded as having solidified at considerable depth below the surface Plutonic (pluːˈtɒnɪk) Adj (Geological Science) (of igneous rocks) derived from magma that has cooled and solidified below the surface of the earth. Also: abyssal Dictionary

In geology, a pluton is a body of intrusive igneous rock (called a plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, stocks, dikes, sills, laccoliths, lopoliths, and other igneous formations. In practice, "pluton" usually refers to a distinctive mass of igneous rock, typically several kilometers in dimension, without a tabular, or flat, shape like those of dikes and sills. Examples of plutons include Denali, Cuillin, Cardinal Peak, Mount Kinabalu and Stone Mountain. The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite. Generally light colored, coarse-grained plutons of these compositions are referred to as granitoids. From Wikipedia, the free encyclopedia

A Jurassic pluton of pink monzonite intruded below a section of gray sedimentary rocks and then was subsequently uplifted and exposed, near Notch Peak, House Range, Utah.

Plutonic igneous rock example: El Capitan Yosemite Nat. Park, California

Plutonic igneous rock example: Kondur Barat, Batam

Intrusive Granite (large crystals)

Note: different crystal sizes

Coarse-grained igneous rock Close up of crystals Note the variety of crystal sizes

Lens-shaped Intrusions Amygdaloidal structure Forms and Structures of Igneous Rocks Intrusive Structures Extrusive Structures Sheet Intrusions Lens-shaped Intrusions Cone-sheet, Ring Dikes Subjacent Plutons Lava Plateau Volcanic Cone Laccolith Batholith Ropy lava Vesicular structure Dikes Sills Phacolith Stock Columnar Jointing Lopolith Diapirs Pillow lava Block lava Amygdaloidal structure

Subjacent Plutons Batholith Large, irregular, major deep seated intrusive masses of very large size, elongated parallel to major tectonic regime. They have an outcrop areas greater than 100 km2 Stock Is similar to batholiths, with surface area less than 100 km2. They have steeply plunging contact with no visible floor. Boss is a term applied to stocks of circular section Diapirs are bodies of rock and/or magma that are buoyant and moves upwards, piercing rocks above them. They appear as ballon like bodies intruded and displaced the country.

Also called Plutonic Rocks form inside the earth. Granite is the most common. Cools slowly - Large crystals (course grain) Magma - molten rock inside the earth.

Phaneritic Over 25% quartz, about 65% or more feldspar Very abundant - often associated with mountain building The term granite includes a wide range of mineral compositions

quartz biotite mica, amphibole feldspar

Phaneritic Has less quartz than garanite Has less dark plagioclase than gabbro Composed mainly of intermediate feldspar and amphibole

Intrusive equivalent of basalt Phaneritic texture consisting of pyroxene and calcium-rich plagioclase Significant % of the oceanic crust

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