EARTH SCI | Rock Cycle

Weathering

breakdown of rocks by physical or chemical means

Erosion

the sediment is transferred from one material to the next through natural forces

Deposition

the materials that have broken down and transferred settle in one location

Igneous rock | Formation

From the word “ignis” meaning fire, they are formed when magma cools and solidifies through the process of crystallization

Extrusive rocks

also known as volcanic rocks, they are molten rocks that solidify at the surface

Intrusive Rocks

also known as plutonic rocks, they are formed at depth

Igneous rocks | Characterization

they are characterized by crystal size and texture

Igneous Rock Texture

overall appearance based on size, shape, and arrangement of the crystals

Phaneritic

Coarse grained or large crystals that visible to the eye

Aphanitic

small crystals that cannot be seen by the eye, even with hand lens

Porphyritic

combination of fine and large crystals

Glossy-textured

non crystalline and has no mineral grains due to incredibly rapid cooling, a mineral loid

Felsic

rocks with light color, implying feldspar (Fel) of the potassium rich variety and (Sic) high percentage of silica

Mafic

dark in color, implying magnesium and iron

Andesitic

light and dark color

Ultramafic

mostly dark-colored

Crystal Size

The slower the cooling, the larger the crystals since the slow cooling time gives the crystals time to form

Sedimentary Rocks

from sediments created by the the uplift and weathering, which are then transported and deposited, then compacted and cemented

Lithification

sediments are transformed into solid sedimentary rocks

Compaction

files of sediments accumulate and the materials below are compacted by the weight of the overlying layers

Cementation

water seeps through pore spaces between particles may contain cementing materials that bind particles together (calcite, silica, and iron oxide)

Strata

distinctive characteristics of sedimentary rocks where fossils or imprints of animals that existed are seen

Detrital Sedimentary Rocks

they come from weathered rock and are identified based on size of particles

Conglomerate

coarse particles with gravel (rounded particles)

Breccia

coarse gravel particles (angular particles)

Sandstone

medium sized sand particles

Slitstone

fine mud particles

Shale

very fine mud particles

Chemical sedimentary rocks

come from weathered rocks and are identified based on chemical composition

Rocks with Calcite

Coquina/limestone, Fossiliferous limestone, chalk

Light-colored rocks with Quartz

Chert

Dark-colored rocks with Quartz

flint

Rock with Gypsum

rock gypsum

Rock with Halite

rock salt

Metamorphic Rocks

they come from pre-existing parent rocks that went under heat, pressure, or chemical agents that lead to changes in mineralogy, texture, and chemical composition

Metamorphism

process of transformation of a parent rock into a textually and mineralogical new rock

Foliation

tectonic forces squeeze rocks as they are heated, the rocks deform into folds and form layers

Stress as a metamorphic agent

applies pressure to rocks, causing spaces to close and producing a more compact rock

Chemically-active Fluids

are catalysts for crystalization, examples include water, CO2, and other volatile chemicals

Slate | Description

foliated and fine-grained

Slate | Parent Rock

Shale

Gneiss | Description

Foliated and medium to coarse-grained

Gneiss | Parent Rock

granite, volcanic rock

Marble | Description

non foliated; medium to coarse-grained

Marble | Parent Rock

Limestone