The Rock Cycle

Front

Geologist Noun

---

[jee-ol-uh-jist]

Back

Geologist

---

A scientist who studies the solid, liquid, and gaseous matter that constitutes the Earth and its history through rocks.

---

Example: A geologist is a scientist who studies the Earth, including rocks and minerals, often by examining them up close in the field to understand their properties.

Front

Magma Noun

---

[mag-muh]

Back

Magma

---

Molten or semi-molten natural material found beneath the Earth's surface, from which igneous rocks are formed by cooling.

---

Example: This diagram shows magma, which is molten rock, located beneath the Earth's oceanic crust, ready to rise at a divergent plate boundary.

Front

Igneous Rock Noun

---

[ig-nee-uhs rok]

Back

Igneous Rock

---

A type of rock that is formed through the cooling and solidification of magma or lava, either above or below ground.

---

Example: This diagram shows how igneous rocks form from cooling magma. Magma cooling slowly underground creates coarse-textured rocks like granite, while lava cooling quickly creates fine-textured rocks like basalt.

Front

Intrusive Adjective

---

[in-troo-siv]

Back

Intrusive

---

Describes igneous rock that has formed from magma that cooled and solidified slowly beneath the Earth's surface.

---

Example: This diagram shows that intrusive igneous rock forms when magma cools slowly deep inside the Earth's crust, resulting in large mineral crystals.

Front

Extrusive Adjective

---

[ik-stroo-siv]

Back

Extrusive

---

Describes igneous rock that has formed from lava that cooled and solidified rapidly on the Earth's surface.

---

Example: This diagram shows magma rising from below the Earth's crust to erupt from a volcano, forming extrusive rock as it cools on the surface.

Front

Sediment Noun

---

[sed-uh-muhnt]

Back

Sediment

---

Naturally occurring material broken down by weathering and erosion, such as rock pieces, mineral grains, or shell fragments.

---

Example: This diagram shows how sediment is created in mountains (source), carried by a river (transport), and deposited to form a delta, a key part of the rock cycle.

Front

Weathering Noun

---

[weth-er-ing]

Back

Weathering

---

The geological process that breaks down rocks, soils, and minerals through contact with the Earth's atmosphere, water, and organisms.

---

Example: This image shows four types of weathering, the process of breaking down rocks. Examples include frost action, where ice splits rock, and biological weathering.

Front

Erosion Noun

---

[ih-roh-zhuhn]

Back

Erosion

---

The geological process in which earthen materials are worn away and transported by natural forces such as wind or water.

---

Example: Water flowing over a cliff erodes the softer rock layer underneath more quickly, causing the harder top rock layer to collapse and the waterfall to retreat.

Front

Compaction Noun

---

[kuhm-pak-shuhn]

Back

Compaction

---

The process by which the porosity of a given form of sediment is decreased as its mineral grains are squeezed together.

---

Example: This diagram shows how pressure squeezes particles together, reducing the space between them. This process, called compaction, is how layers of sediment become rock.

Front

Cementation Noun

---

[see-men-tey-shuhn]

Back

Cementation

---

The process where dissolved minerals crystallize and bind sediment particles together into solid rock, hardening and gluing them.

---

Example: This diagram shows how loose sediments (white circles) are glued together by natural cement (dark, shaded areas), which is how sedimentary rock is formed.