Sedimentary Rocks Quiz

Questions and Answers

How do sedimentary rocks form?

Sedimentary rocks form when small pieces of sediments are packed together.

What do other rocks need to become before they can become sedimentary rock?

They need to become sediment.

What two processes form sediments?

Weathering and erosion.

What three characteristics are used to classify sedimentary rocks?

Rock type, texture, and structure. Signup and view all the answers

What are the three types of sedimentary rock?

Clastic, chemical, and organic. Signup and view all the answers

How do clastic sedimentary rocks form?

They form when organic matter and sedimentary rocks are compacted together. Signup and view all the answers

What are the four sizes of sediment that might make up a clastic rock?

Boulder, cobble, sand, and clay or silt. Signup and view all the answers

Name one rock that compacted sand might form.

Sandstone. Signup and view all the answers

Name one rock that compacted clay might form.

Siltstone. Signup and view all the answers

Give one example of a chemical sedimentary rock.

Gypsum. Signup and view all the answers

Name one type of organic matter that might be used to form an organic sedimentary rock.

Decomposed plants. Signup and view all the answers

What does it mean if a sedimentary rock has a coarse texture?

It is made up of large obvious particles. Signup and view all the answers

What does it mean if a sedimentary rock has fine texture?

There are no visible sediments. Signup and view all the answers

How is a crystalline rock different from a resinous rock?

A crystalline rock has a crystal shape, while a resinous rock appears to contain resin. Signup and view all the answers

What does it mean if a rock has a glassy structure?

It looks or seems shiny. Signup and view all the answers

How do metamorphic rocks form?

They form when existing rocks are subjected to heat and pressure. Signup and view all the answers

What does it mean if a rock is foliated?

It means that the rock cleaves along its existing layers. Signup and view all the answers

What is a parent rock?

It is a metamorphic rock before it had heat and pressure applied. Signup and view all the answers

What is the parent rock of schist?

Phyllite. Signup and view all the answers

What is the parent rock of slate?

Shade and mudstone. Signup and view all the answers

What is the parent rock of quartzite?

Quartz and sandstone. Signup and view all the answers

What are rocks?

They are mixtures of different mineral crystals. Signup and view all the answers

What is the continental crust?

Granite (rock) composed of quartz, biotite, and feldspar. Signup and view all the answers

What is the oceanic crust?

Basalt (rock) composed of pyroxene and olivine. Signup and view all the answers

What is rock?

A mixture of minerals, rock fragments, volcanic glass, or organic matter. Signup and view all the answers

Most rocks contain?

One or more common minerals called rock forming minerals. Signup and view all the answers

What does the rock cycle show?

It shows how rocks slowly change through time. Signup and view all the answers

What is an igneous rock?

A rock that forms when magma or lava cools and hardens. Signup and view all the answers

What is a metamorphic rock?

Forms from other rocks changed by heat and pressure. Signup and view all the answers

What is a sedimentary rock?

Forms when pieces of sediments are cemented together. Signup and view all the answers

What does matter refer to?

Matter cannot be created nor destroyed. Signup and view all the answers

What are grains?

Fragments that make up a rock. Signup and view all the answers

What do geologists use to classify rocks?

A grain's size, shape, and chemical composition. Signup and view all the answers

What is texture in rocks?

The grain size and the way grains fit together. Signup and view all the answers

How is texture used to classify rocks?

It provides clues to determine the environment in which a rock formed. Signup and view all the answers

What does composition refer to in geology?

The minerals or grains present in a rock. Signup and view all the answers

What is the temperature range of magma?

650 degrees to 1,200 degrees. Signup and view all the answers

What is lava?

Magma that reaches Earth's surface. Signup and view all the answers

What is another heat source for the formation of igneous rocks?

Decay of radioactive elements. Signup and view all the answers

What is an intrusive igneous rock?

Rock formed from magma that cools slowly below the surface. Signup and view all the answers

How do extrusive igneous rocks form?

They form from quickly cooling lava exposed to air and water. Signup and view all the answers

What are examples of volcanic glass?

Pumice, obsidian, and scoria. Signup and view all the answers

How to identify igneous rocks?

By where they form, type of magma, texture, melting temperature, and color. Signup and view all the answers

What is mafic (basaltic) rock?

These rocks are more dense, darker in color, and high in iron and magnesium. Signup and view all the answers

What is felsic rock?

Less dense, lighter in color, high in aluminum and silicon. Signup and view all the answers

What is andesitic rock?

Rocks with mineral compositions between basaltic and granitic rocks. Signup and view all the answers

What are examples of igneous rocks?

Basalt and obsidian. Signup and view all the answers

What are examples of metamorphic rocks?

Gneiss and marble. Signup and view all the answers

What are examples of sedimentary rocks?

Conglomerate and limestone. Signup and view all the answers

What does foliated mean?

Curvy thin crystal lines. Signup and view all the answers

What does non-foliated mean?

No lines in the rock structure. Signup and view all the answers

What percentage of rocks on the surface are sedimentary?

75%. Signup and view all the answers

What are the classifications of sedimentary rocks?

Detrital/clastic, chemical, or organic. Signup and view all the answers

Define compaction.

Pressure overlaying sediments packs grains and squeezes water from pores. Signup and view all the answers

What is cementation?

Pore spaces fill with ions that precipitate from water. Signup and view all the answers

What are organic rocks made of?

Once living things. Signup and view all the answers

Study Notes

Formation and Types of Sedimentary Rocks

Sedimentary rocks form through the packing together of sediments.
Pre-existing rocks must first be transformed into sediment to become sedimentary rocks.
Sediments are generated through weathering (breaking down rock and soil) and erosion (movement of particles by wind or water).

Classification of Sedimentary Rocks

Sedimentary rocks are classified based on rock type, texture, and structure.
Three primary types of sedimentary rocks are:
- Clastic: Formed from pre-existing rocks pressed together.
- Chemical: Result from dissolution and precipitation of minerals, often involving evaporated solutions.
- Organic: Composed of compacted organic matter like decomposed plants.

Characteristics of Sediments

Clastic sedimentary rocks can be categorized by the size of their sediment:
- Boulder size (e.g., conglomerate)
- Cobble, pebble, or granule size (e.g., breccia)
- Sand size (e.g., sandstone, graywacke)
- Finer sizes (e.g., siltstone, clay)

Texture and Structure of Rocks

Coarse texture indicates large, visible particles in the rock.
Fine texture suggests the absence of visible sediments.
Crystalline rocks have a defined crystal structure, whereas resinous rocks resemble resin.
A glassy structure appears shiny and smooth.

Formation of Metamorphic Rocks

Metamorphic rocks develop from existing rocks subjected to high temperatures and pressures deep within the Earth.
Foliation refers to the layering seen in some metamorphic rocks; they cleave along these layers.
Parent rocks are the original rocks before metamorphism occurs, such as:
- Schist: Parent rock is phyllite.
- Slate: Parent rocks include shale and mudstone.
- Quartzite: Parent rock is sandstone.

Basic Concepts of Rocks and the Rock Cycle

Rocks are aggregates of mineral crystals and can consist of rock fragments, volcanic glass, and organic materials.
The continental crust is primarily granite, composed of quartz, biotite, and feldspar.
The oceanic crust consists mainly of basalt, composed of pyroxene and olivine.
Most rocks are made up of common minerals such as quartz, feldspar, mica, or calcite.

Rock Cycle Overview

The rock cycle illustrates the slow transformation of rocks over time through various geological processes.
Igneous rocks form from the cooling of magma or lava.
Metamorphic rocks are altered by heat and pressure.
Sedimentary rocks form from cemented sediments.

Identification and Composition

Rocks can be identified based on grain size, shape, chemical composition, and texture.
Grains are fragments that compose the rock.
Igneous rocks can be classified as:
- Mafic (Basaltic): Dense, dark, high in iron and magnesium.
- Felsic: Less dense, lighter in color, high in aluminum and silicon.
- Andesitic: Intermediate composition between basaltic and granitic rocks.

Rock Examples and Classifications

Common examples:
- Igneous Rocks: Basalt, obsidian.
- Metamorphic Rocks: Gneiss, marble.
- Sedimentary Rocks: Conglomerate, limestone.
Foliated rocks show curvy, thin crystal lines, while non-foliated rocks lack such lines.

Geological Processes

Compaction: Pressure from overlaying sediments compresses grains and expels pore water.
Cementation: Pore spaces are filled with ions that precipitate from water, forming solid bonds.

Additional Key Facts

Approximately 75% of rocks on the Earth's surface are sedimentary.
Organic sedimentary rocks are formed from once-living materials.

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Description

Test your knowledge about the formation of sedimentary rocks with this engaging quiz. Explore how sediments are formed and the processes involved in turning pre-existing rocks into sedimentary rocks. Perfect for geology enthusiasts and students alike!