GEOL 103

Halite

A mineral form of sodium chloride (NaCl), often found in evaporite deposits.

What is the cleavage type of Halite?

The cleavage of Halite is cubic.

What is a special property of Halite used for identification?

Halite can taste salty.

Gabbro

An igneous rock that is mafic and phaneritic in texture.

What type of rock is Gabbro?

Gabbro is an igneous rock.

What is the texture of Gabbro?

Gabbro has a phaneritic texture.

Sediment

Material derived from pre-existing rock, biogenic sources, or precipitated by chemical processes, deposited at, or near, the earth's surface.

What are the processes involved in making sedimentary rocks?

The processes include weathering, erosion, and transportation.

What is weathering?

Processes acting on Earth’s surface to break down pre-existing rock.

What are the two types of weathering?

Chemical weathering and mechanical weathering.

What is mechanical weathering?

The physical breakdown of rocks into smaller pieces without changing their chemical composition.

What are the three products of weathering?

Quartz sand, clay, and minerals in solution.

What is erosion?

Transportation of materials away from the site of weathering.

What is lithification?

The process by which sediments compact under pressure, expel fluids, and become solid rock.

What is compaction in lithification?

Pressure from overlying sediments reduces pore space and removes water.

What is cementation in lithification?

Precipitation of secondary minerals from solution that fills pore spaces and binds grains together.

Clastic sedimentary rocks

Rocks made from broken pieces of other rocks cemented together.

Chemical sedimentary rocks

Rocks formed from the dissolved minerals that precipitate out of solution.

What is breccia?

A clastic rock with angular fragments, indicating short transportation distances.

What is conglomerate?

A clastic rock with well-rounded grains, indicating longer transportation distances.

What are evaporites?

Chemical sedimentary rocks that form from the evaporation of water.

What is coal?

Fossilized plant tissue formed in a bog.

What is chert?

A hard sedimentary rock that is chemically or biologically formed, often composed of silica.

Phaneritic texture

A texture of igneous rocks that cool slowly, allowing for the growth of large crystals.

What is obsidian?

An igneous rock with a glassy texture, formed by rapid cooling.

What is a clast?

A piece of a rock.