IGNEOUS ROCKS Igneous derived from the Latin word

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IGNEOUS ROCKS Igneous – derived from the Latin word ignis, meaning Fire.

IGNEOUS ROCKS Igneous – derived from the Latin word ignis, meaning Fire.

IGNEOUS ROCKS Lava is molten rock found at or near Earth’s surface. Magma is

IGNEOUS ROCKS Lava is molten rock found at or near Earth’s surface. Magma is molten rock found beneath Earth’s surface. Igneous Rocks form from both lava and magma.

3 Ways Magma Can Form • Pressure – The high pressure inside Earth causes

3 Ways Magma Can Form • Pressure – The high pressure inside Earth causes Hot rocks and minerals to remain solid. When those hot rocks rise and the pressure lowers, the minerals melt. • Temperature – High temperatures melt minerals. Each mineral has a different melting point – so some minerals melt when others remain solid. • Composition – If fluids, such as water, combine with the rock, the composition of the rock changes which lowers the melting point enough for it to melt and lower temperatures.

Igneous Rock • Forms when hot, liquid rock or magma, cools and solidifies •

Igneous Rock • Forms when hot, liquid rock or magma, cools and solidifies • Found near volcanic activity • Liquid magma is a mixture of many minerals

Intrusive & Extrusive Those igneous rocks that form from magma are referred to as

Intrusive & Extrusive Those igneous rocks that form from magma are referred to as INTRUSIVE = Inside Those igneous rocks that form from lava are referred to as EXTRUSIVE = Outside

Lava Extrusive La va La Intrusive Magma va

Lava Extrusive La va La Intrusive Magma va

TEXTURE of Igneous Rocks • Determined by how fast the magma cools • Smooth

TEXTURE of Igneous Rocks • Determined by how fast the magma cools • Smooth grained rocks are formed by magma that cools quickly (Extrusive) • Coarse grained rocks are formed when magma cools slowly (Intrusive)

IGNEOUS ROCK FORMATIONS Intrusive Extrusive • Form Below Earth’s surface and inside the Earth

IGNEOUS ROCK FORMATIONS Intrusive Extrusive • Form Below Earth’s surface and inside the Earth • Forms on the Earth’s surface • Intrusive rocks have a coarse grained texture because ? • Extrusive rocks have a smooth texture because ?

COMPOSTITION of Igneous Rocks • Light colored rocks are less dense and rich in

COMPOSTITION of Igneous Rocks • Light colored rocks are less dense and rich in Quartz Felsic (aluminum, potassium, silicon and sodium) • Dark colored rocks more dense and contain Plant Nutrients. (calcium, iron, magnesium) Mafic are

Igneous Rock QUESTION Obsidian is a dark-colored volcanic glass that forms from the very

Igneous Rock QUESTION Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form. • Is this rock Felsic or Mafic? • Is it fine-grained or coarse-grained? • Is this rock Intrusive or Extrusive? Mafic, fine grained, extrusive

Andesite – Fine-grained, extrusive Felsic igneous rock

Andesite – Fine-grained, extrusive Felsic igneous rock

Basalt is also an abundant rock on the Moon. Much of the Moon's surface

Basalt is also an abundant rock on the Moon. Much of the Moon's surface is underlain by basaltic lava flows and flood basalts. These areas of the Moon are known as "lunar maria. " Basalt – Fine-grained, extrusive Mafic

Diorite – Coarse-grained, intrusive. Mixture of Mafic and Felsic

Diorite – Coarse-grained, intrusive. Mixture of Mafic and Felsic

Gabbro – Coarse-Grained, intrusive, Mafic igneous rock

Gabbro – Coarse-Grained, intrusive, Mafic igneous rock

Pumice – Extremely Fine-Grained, Extrusive Felsic Igneous Rock Form during explosive volcanic eruptions from

Pumice – Extremely Fine-Grained, Extrusive Felsic Igneous Rock Form during explosive volcanic eruptions from the cooling of the frothy magma

Forms when some volcanoes erupt, a rush of gas blows out of the vent.

Forms when some volcanoes erupt, a rush of gas blows out of the vent. This gas was once dissolved in the magma below. The gas often blows out small bodies of magma that solidify as they fly through the air. Scoria – Extremely fine-grained, Extrusive Mafic Igneous Rock