Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 34 views

    Rocks (Grade 11)

    Uploaded by

    Kristhia Cyra Rivera
    Earth's crust consists of solid rock up to 2,900 km deep. Rocks are naturally occurring aggregates of minerals that are classified into three main types: igneous, sedimentary, and metamorphic. Igneous rocks form from cooling magma, either below ground as intrusive rocks or above ground as extrusive rocks. Sedimentary rocks form from compression of sediments and include clastic, chemical, and organic types. Metamorphic rocks form from changes to existing rocks through heat, pressure, and chemical processes.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Rocks (Grade 11)

    Uploaded by

    Kristhia Cyra Rivera
    34 views2 pages
    Earth's crust consists of solid rock up to 2,900 km deep. Rocks are naturally occurring aggregates of minerals that are classified into three main types: igneous, sedimentary, and metamorphic. Igneous rocks form from cooling magma, either below ground as intrusive rocks or above ground as extrusive rocks. Sedimentary rocks form from compression of sediments and include clastic, chemical, and organic types. Metamorphic rocks form from changes to existing rocks through heat, pressure, and chemical processes.

    Copyright

    © © All Rights Reserved

    Available Formats

    PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    Earth's crust consists of solid rock up to 2,900 km deep. Rocks are naturally occurring aggregates of minerals that are classified into three main types: igneous, sedimentary, and metamorphic. Igneous rocks form from cooling magma, either below ground as intrusive rocks or above ground as extrusive rocks. Sedimentary rocks form from compression of sediments and include clastic, chemical, and organic types. Metamorphic rocks form from changes to existing rocks through heat, pressure, and chemical processes.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    34 views2 pages

    Rocks (Grade 11)

    Uploaded by

    Kristhia Cyra Rivera
    Earth's crust consists of solid rock up to 2,900 km deep. Rocks are naturally occurring aggregates of minerals that are classified into three main types: igneous, sedimentary, and metamorphic. Igneous rocks form from cooling magma, either below ground as intrusive rocks or above ground as extrusive rocks. Sedimentary rocks form from compression of sediments and include clastic, chemical, and organic types. Metamorphic rocks form from changes to existing rocks through heat, pressure, and chemical processes.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    You are on page 1of 2

    Topic #3: ROCKS

    Earth is a solid rock to a depth of 2,900 kilometers, where mantle meets the liquid outer core. A rock is
    a naturally occurring solid aggregate of one or more minerals. The aggregate minerals forming the rocks are
    held together by chemical bonds. Grains can be different in color, texture, and sizes. Geologists then group
    rocks into three categories based on how the rocks form: igneous sedimentary and metamorphic rock.
    Petrology is the scientific study of rocks. Petrologists classify rocks based on how they were formed.

    Three types of Rocks


    Igneous Rocks formed from hardening and crystallization of magma or molten material that originates
    deep within the earth.

    Two types of igneous rock:

    A. Extrusive/Volcanic rock - forms when magma makes its way to Earth’s surface as lava and then
    cools. The crystals are very small (fine grained) since the cooling process is fast.

    B. Intrusive/Plutonic - It cools slowly beneath the Earth surface and are created by magma. The
    intrusive igneous rocks have very large crystals (coarse grained).

    Igneous rocks are classified based on


    1. COMPOSITION
    FELSIC - light in color; feldspar and silicates
    MAFIC - dark in color; made up of magnesium and iron
    INTERMEDIATE – between mafic and felsic
    ULTRAMAFIC - very dark color

    2. TEXTURE - overall appearance of rock


    APHANISTIC - fine grained
    PHANERITIC - coarse grained
    PORPHYRITIC - large crystals with small crystals
    GLASSY - non-ordered solid from rapid quenching
    PYROCLASTIC - composite of ejected fragments

    Examples: Obsidian, pumice, basalt, granite, diorite, gabbro.

    Sedimentary rocks provide information about surface conditions that existed in the Earth’s past.

    • Particles of sand, shells, pebbles, and other fragments of materials called sediments, accumulate
    in layers and over long period of time harden into rocks.
    • Compaction-due to increase of pressure of layered sediments it bind together to form the
    sedimentary rocks.
    •
    Three types of sedimentary rocks
    A. Clastic Sedimentary Rock - formed from accumulation of clasts: little pieces of broken rocks and
    shells. Examples: conglomerate, breccia, sandstone, shale.

    B. Chemical Sedimentary Rock - formed when dissolved minerals precipitate from a solution.

    Example: Coal - composed of organic matter in the form of plants fragments.

    C. Organic Sedimentary Rock - rocks formed from the accumulation of animal debris.

    Metamorphic Rocks forms from pre-existing rocks: either metamorphic, igneous, sedimentary.

    • Metamorphism - transformation of one rock type into another.

    2 TYPES OF METAMORPHISM
    1. Regional - due to changes in pressure and temperature over large region of the crust

    2. Contact - mainly by heat due to contact with magma

    CLASSIFICATION:
    a. Texture – refers to the size arrangement ad grains within the rock.
    b. Foliation – any planar arrangement of mineral grains or structural features within the rock.
    c. Foliated – appeared banded or layered, contains crystals Example: mica
    d. Non-foliated – made up of only few minerals

    You might also like